Abstracts

Oral Free Paper Sessions

Sunday, 9 September 2018, 08:30 - 12:00, Room A2

OFP-01 | Joint Session: Molecular Pathology / Haematopathology

OFP-01-001

Microfluidic-based automated multiplex immunophenotyping and imaging

B. Pelz^*, D. Migliozzi, G. Cappi, D. Dupouy, M. Gijs

*EPFL, Laboratory of Microsystems 2, Lausanne, Switzerland

Background & Objective: The tumour microenvironment plays a vital role in cancer development. Multiplex immunostainings allow studying the interaction of different cell types in the tumour microenvironment using a single tissue slide. The objective is to develop a fully automated microscope integrated method for rapid 10-plex fluorescent immunostaining and imaging of tissue sections.

Method: FFPE tonsil sections underwent manual dewaxing and antigen retrieval step. All subsequent steps of staining, antibody elution and imaging were automated on the microscope integrated microfluidic device. A single tissue section was stained sequentially for CD3, CD4, CD8, CD20, CD56, CD68, FOXP3, PD-1, PD-L1 and CK with mouse or rabbit primary antibody and corresponding Alexa Fluor labelled secondary antibody. The section was imaged after each staining step and subsequently eluted before staining the next marker.

Results: Our microscope integrated microfluidic system allowed automated 10-plex staining with conventional primary and fluorescently labelled secondary antibodies in less than five hours, including image acquisition steps. Protocol optimization resulted in a high signal to background noise ratio for each marker, while fully eluting antibodies from the previous staining step.

Conclusion: With the microscope integrated microfluidic system, it is possible to perform fast multiplex stainings including image acquisition without removing the tissue slide. Moreover, due to the sequential nature of the system it would be easily possible to further increase the number of markers in the multiplex staining. We believe that this technique greatly facilitates the execution of high-plex stainings and thereby the discovery of novel tumour-microenvironment interactions.

OFP-01-002

The potential biomarker HR23b regulates sensitivity towards histone deacetylase inhibitors (HDACi) via the NGFR death receptor pathway

S. Wagener^*, M. A. Ihle, C. Alidousty, C. Heydt, J. Fassunke, S. Merkelbach-Bruse, R. Büttner

^*University Hospital Cologne, Institute of Pathology, Germany

Background & Objective: Deregulation of histone deacetylases (HDACs) plays an important role in tumourigenesis and progression. Restoring a regular acetylation profile by HDAC inhibitors (HDACi) is a promising therapeutic approach. Human Rad Homolog B (HR23b), has been identified as a predictive biomarker of HDACi sensitivity in haematological and hepatocellular tumours. We showed previously that HDACi also exhibit antiproliferative and pro-apoptotic effects in sarcomas in dependence of HR23b expression. We therefore aim to elucidate the regulatory relationship between HR23b expression and sensitivity towards HDACi.

Method: A stable knockout of HR23b was generated in a malignant peripheral nerve sheath tumour (MPNST) cell line (ST-8814) using CRISPR /Cas9-technology. An efficient knockout was verified both, on DNA- and expression level. Its influence on proliferation and apoptosis was measured with the ApoTox ™ Glo assay. HDACi vorinostat was adminstered at IC50 concentration to wildtype and HR23bKO cells. Afterwards expression analysis of important signaling pathways was performed with the nCounter PanCancer Pathways panel on a NanoString platform.

Results: qPCR and Western Blot analysis confirmed a stable knockout of HR23b in ST-8814 cells. HR23b dependent sensitivity towards HDACi is mediated by apoptosis induction via the NGFR death receptor pathway. In contrast, HR23b loss reduces apoptosis induction and shifts response to TLR2-regulated autophagy.

Conclusion: Understanding the key pathways by which HDAC inhibitors affect tumour growth plays a major role for future therapeutic approaches. In particular, the importance of HR23b as a predictive biomarker should help to select patients who may benefit from HDACi therapy.

OFP-01-003

Patient-derived colorectal cancer explants retain the histological and molecular key features of their primary counterparts

S. Mata^*, S. Abreu, R. Fonseca, B. Filipe, S. Morgado, I. Francisco, M. Mesquita, T. Franchi Mendes, C. Albuquerque, P. Chaves, E. R. Boghaert, V. E. Santo, I. Rosa, C. Brito

^*IPOLFG, Anatomia Patológica, Lisboa, Portugal

Background & Objective: Colorectal cancer (CRC) 5-year overall survival is 64.9%. Chemotherapy responses are limited. In order to improve clinical outcomes, reliable models predictive of drug response are needed. Patient derived explants (PDE) are ex-vivo cultures that can overcome representability limitations of other models.

Method: Our aim is to develop PDEs from CRC samples dissociated and placed in a dynamic system; evaluate their viability by metabolic and morphologic evaluations; characterize their phenotype (architecture, senescent phenotype, stroma cellularity, inflammatory cells); and assess PDE representation of the primary tumour (gland formation, p53 and mismatch repair proteins, microsatellite instability, KRAS exon2 and BRAFV600E mutations).

Results: Eleven adenocarcinomas were successfully cultured. All PDEs retained their originals’ glandular architecture. There was viable tumour for at least 28 days (~46(28-87 days)) and for most of the cases (N=7/11) viable stroma was evident as long as neoplastic cells were present. PDEs (N=10/11) lost architectural complexity and stroma cellularity at the first evaluation (days 7-11), but less significantly thereafter. Tumour cells progressively acquired a senescent phenotype. PDEs (N=10/11) replicate the tumours’ immunohistochemical and genetic features. KRAS mutated clones seem to be positively selected in culture (N=3/5). For one PDE, KRAS status and p53 staining were consistently different from the primary counterpart since the starting point.

Conclusion: PDE is an efficient method to culture CRC. Overall the key pathological features of the primary tumours are retained over time, supporting their use in drug predictive assays. Divergent results may be due to intratumoural heterogeneity and optimization in tumour collection should improve PDE representation of the tumour.

OFP-01-004

A study of gene expression profiling in gastric adenocarcinoma: comparison between Epstein-Barr-Virus positive and microsatellite unstable tumours

I. Gullo^*, P. Oliveira, C. Oliveira, F. Carneiro

^*Centro Hospitalar São João, Pathology Dept., Porto, Portugal

Background & Objective: Different molecular classifications have been proposed for gastric cancer (GC), trying to decipher its molecular heterogeneity. Epstein-Barr virus positive (EBV+) and microsatellite unstable (MSI-high) GCs are well-recognized molecular subgroups. The Singapore-Duke group classification is based on gene expression data and identified three GCs subtypes, with implications for response to therapy: mesenchymal, proliferative and metabolic [doi:10.1053/j.gastro.2013.05.010]. In this study we aimed at exploring and comparing RNA expression profiling of EBV+ and MSI-high GCs.

Method: Fifteen EBV+ and 27 MSI-high GCs were selected by RNA in situ hybridization for EBV and PCR/fragment analysis for MSI, respectively. RNA expression profiling was performed using the NanoString nCounter platform, analysing 474 genes, previously published [doi:10.1136/esmoopen-2015-000009] and additional 21 genes, associated with immune response. We searched for differentially expressed genes (FDR<0.05) between the EBV+ and MSI-high molecular groups (nSolver Analysis Software).

Results: EBV+ GCs showed up-regulation of genes related to immune response (T-cell activation, IFNγ/TNFα pathways, proinflammatory cytokines/chemokines) and degradation of extra-cellular matrix. Gene expression data of a subset of EBV+ GCs fitted into the mesenchymal subtype (30 out of 31 genes, 96.8%). In contrast, MSI-high GCs showed enrichment of genes related to cell division, cell cycle and mitotic activity and, accordingly, could be classified as GCs belonging to the proliferative subtype (27 out of 34 genes, 79.4%).

Conclusion: The search for EBV infection and MSI-high status might aid on the stratification of GC into molecular subtypes with clinical relevance. We demonstrated the differential transcriptional profile between EBV+ and MSI-high GCs, which have putative therapeutic implications.

OFP-01-005

Epigenetic changes in DAXX and/or ATRX negative pancreatic neuro-endocrine tumours

A. Di Domenico^*, C. Pipinikas, C. Simillion, T. Wiedmer, R. Maire, C. Thirlwell, A. Perren, I. Marinoni

^*University of Bern, Institute of Pathology, Switzerland

Background & Objective: MEN1, DAXX and ATRX are the most commonly mutated genes in Pancreatic Neuroendocrine Tumours (PanNETs). Interestingly all these genes are involved in epigenetic regulation. DAXX and ATRX mutations correlate with loss of protein and predict for poor patient outcome. DAXX and ATRX participate in the chromatin structure organization as well as in regulating DNA methylation (DNAme) while MEN1 recruits MLL1 (mixed lineage complex) which plays a crucial role in chromatin remodelling. We hypothesized that MEN1 mutations and DAXX/ATRX loss induce epigenetic changes which mediate PanNET progression. We aim to describe epigenetic profiles of MEN1 mutated and DAXX/ATRX negative PanNETs and to identify specific epigenetically regulated pathways that contribute to tumour development.

Method: We analysed genome wide DNAme profiles (Illumina 450K) in 55 PanNETs. miRNA expression (800 miRNA) in a subset of 24 PanNETs and the expression of a panel of 398 potentially epigenetically regulated genes (Nanostring) on 48 matching primary tumours.

Results: We found that MEN1 mutated and DAXX/ATRX negative tumours showed a specific methylation profile for 3078 genomic regions, including 393 differentially methylated promoters. Thirtyone miRNAs were differentially expressed in DAXX/ATRX negative vs. DAXX/ATRX positive tumours. We integrated these data with publically available RNAseq data. Based on these analyses we identified 398 genes for which the expression was assessed and validated.

Conclusion: Our results strongly support the hypothesis that DAXX/ATRX loss and MEN1 mutation in PanNETs result in consistent dysregulation of DNAme, accompanied by expression changes in genes and miRNAs.

OFP-01-006

Can routine gene mutation profiles help favor a specific tumour origin?

M. Rassy^*, T. Sticca, I. Laios, D. Larsimont

^*Institut Jules Bordet, Pathology, Etterbeek, Belgium

Background & Objective: Gene mutation profiles can be extracted from routinely used Next Generation Sequencing (NGS). However, can they be used as a complementary tool to favor a tumour origin over another?

Method: 503 quality-controlled cases were routinely sequenced on the Illumina Miseq, using the Truseq Amplicon Cancer Panel (48 genes), at the Jules Bordet Institute. For each case, we retrieved clinical data, pathology results, molecular quality control scores and detailed DNA variants. We then used a multinomial logistic regression test with a p-value threshold of 0.01 for more power.

Results: From a total of 72076 DNA variants, only 2548 (3.5%) were exonic quality-controlled modifying non-polymorphism variants, reported in COSMIC as pathogenic. That averaged 5 mutations per case. Cases were mainly colorectal cancers (40.0%), lung cancers (27.2%) and melanomas (10.5%). Genes favoring lung over colorectal cancer had low sensitivity (3.6-12.4%) and high specificity (97.0-99.0%): NPM1, EGFR, ABL1 and VHL. APC was the only high sensitivity/specificity gene (43.3%/89.1%) favoring colorectal over lung cancer, compared to PTEN (9.5%/90.5%) and PDGFRA (4.5%/95.6%). Analysis of melanoma and colorectal cancer yielded higher sensitivity (39.6-58.2%) and lower specificity (81.1-94.5%) genes: NRAS and BRAF favoring melanoma, and APC and TP53 favoring colorectal cancer.

Conclusion: Lung cancer and colorectal cancer were distinguished by few low sensitivity/high specificity mutated genes, with the exception of APC. Genes distinguishing between melanoma and colorectal cancer had higher sensitivity but slightly lower specificity (NRAS, BRAF, APC and TP53). Bearing in mind these limitations, NGS can be considered complementary to the gold standard microscopic examination for tumour origin identification.

OFP-01-007

STARTRK-2 basket trial for TRK, ROS1 and ALK fusions in cancer patients treated in a single institution

A. Tysarowski^*, M. Wagrodzki, K. Seliga, A. Szumera-Cieckiewicz, J. H. Christiansen, S. J. Potts, M. Kotarska-Puerto, J. A. Siedlecki, M. Prochorec-Sobieszek

^*Cancer Center Institute, Dept. of Pathology, Warsaw, Poland

Background & Objective: The STARTRK-2 (Studies of Tumour Alterations Responsive to Targeting Receptor Kinases) trial is a potentially registration-enabling Phase 2 global basket trial of the investigational tyrosine kinase inhibitor compound entrectinib in patients with solid tumours harboring TRK, ROS1, or ALK gene fusions. Phase 1 studies of entrectinib reported a 79% Overall Rate of Response across multiple histology types in patients with gene fusions who were naive to inhibitors of these targets, received an efficacious dose, and had extracranial disease. In general patients harboring these gene fusions account for <3% of cancer population; however, they have been seen in over 40 histologies, including gastrointestinal, lung, head & neck, and sarcoma. In this presentation, we report on the occurrence of TRK, ROS1, and ALK fusions in patients treated in Cancer Center Institute of Oncology.

Method: The occurrence of TRK, ROS1, and ALK gene fusions in solid tumours was studied in FFPE specimens from 645 patients. We used 2-step diagnostic test. At first, the IHC screening was performed using a pan-receptor tyrosine kinase cocktail of antibodies targeting those proteins, secondly an RNA-based anchored multiplex-PCR next generation sequencing (NGS) assay was performed in IHC positive specimens.

Results: The 221 out of 645 clinical specimens screened by IHC were positive and further analyzed by NGS. The presence of gene fusions was confirmed in 17 (2,6%) of them.

Conclusion: The two-step testing approach is an effective strategy to identify patient populations with low prevalence of molecular alterations and can be included into standard clinical practice.

OFP-01-008

Epitranscriptomics in testicular germ-cell tumours: the value of m6A and related proteins for tumour subtyping and prognostication

J. Lobo^*, A. L. Costa, M. Cantante, R. Guimarães, P. Lopes, L. Antunes, I. Braga, J. Oliveira, M. Pelizzola, C. Jerónimo, R. Henrique

^*IPO Porto, Dept. of Pathology, Portugal

Background & Objective: Epitranscriptomics is a growing new field in Science. RNA modifications, such as N-6-methyladenosine(m6A), play a role in various biological processes but their role in cancer remains largely unexplored. We aimed to assess the value of these epimarkers in a cohort of Testicular Germ Cell Tumours (TGCTs).

Method: In silico analysis (TCGA database) showed altered expression of the writer KIAA1429 and reader YTHDF3 in 51% and 48% of TGCTs, hence they were chosen for further validation. Formalin-fixed paraffin-embedded (FFPE) tissues from 122 TGCT patients (2005-2016) were included. RNA extraction, cDNA synthesis and real-time qPCR (Taqman assay) for KIAA1429 and YTHDF3 was performed. Immunohistochemistry for KIAA1429, YTHDF3 and m6A was performed and staining intensity assessed.

Results: There were significant differences in KIAA1429/YTHDF3 mRNA expression levels among tumour subtypes, with Seminomas (SEs) exhibiting higher levels than Non-Seminomatous tumours (NSTs) (p<0.01, p<0.01). KIAA1429 showed the best performance, discriminating SEvsNST with AUC=0.85(sensitivity 77.3%, specificity 81.1%, PPV 71.6%, NPV 85.3%, Accuracy 79.7%). Stage I patients had higher YTHDF3 expression(p=0.04). A moderate correlation was found between expression levels of KIAA1429 and YTHDF3(correlation coefficient 0.44). Immunohistochemistry reproduced transcript findings, with patients showing strong KIAA1429 immunoexpression exhibiting higher mRNA expression levels(p<0.001). KIAA1429 immunostaining also discriminated SEvsNST(p<0.01). Patients with strong m6A immunoexpression showed significantly higher KIAA1429 mRNA expression levels and stronger KIAA1429 immunostaining (p<0.001, p<0.01), indicating an association between the writer and the established RNA modification (m6A). KIAA1429/YTHDF3 were differentially expressed among individual TGCT components, both at mRNA and immunohistochemistry levels.

Conclusion: We confirmed that m6A and related proteins are differentially expressed among TGCT subtypes and might serve as useful biomarkers for diagnosis and prognosis.

OFP-01-009

Monitoring leukemic mutations using ultrasensitive IBSAFE digital droplet analysis predicts relapse of acute myeloid leukemia

L. Pettersson^*, Y. Chen, A. M. George, C. Orsmark-Pietras, H. Lilljebjörn, R. Rigo, V. Lazarevic, T. Fioretos, G. Juliusson, L. H. Saal, M. Ehinger

^*Halland Hospital Halmstad, Clinical Pathology and Cytology, Sweden

Background & Objective: Optimal management of patients with acute myeloid leukemia (AML), a dismal disease with poor prognosis, depends on accurate monitoring of minimal residual disease (MRD), which predicts outcome and affect treatment decisions. Current MRD methods either suffers from limited sensitivity or can only be applied on leukemias carrying the targeted mutation. We developed an innovative digital droplet PCR technique, IBSAFE, that enables an improved limit of detection down to 0.001% mutant allele frequency (MAF). Given that even patients with negative multicolor flow cytometry (MFC)-MRD results (<0.1%) often have poor prognosis, we set out to analyze AML patients using IBSAFE to investigate if this method could predict the outcome.

Method: 10 relapsing and 4 non-relapsing AML patients were retrospectively tested for MRD with IBSAFE in bone marrow aspirates taken at several follow-up time points. First, the mutational profile was determined at diagnosis and relapse by next generation sequencing (NGS). Mutations for MRD monitoring were selected with priority towards mutations in recurrently mutated genes.

Results: For all relapsing patients, IBSAFE was able to track early recurrence of leukemic clones. At most follow-up time points, residual leukemia was apparent with IBSAFE, but absent with MFC-MRD. For the non-relapsing patients, some mutations were detected during follow-up, but the levels gradually declined in response to different therapeutic strategies.

Conclusion: We demonstrate that our IBSAFE method can track early recurrence of leukemic clones, with possible applications in clinical routine AML-MRD analyses. The advantage as compared to other MRD methods is the high sensitivity and applicability on virtually all AML patients.

OFP-01-010

Burkitt-like lymphoma with 11q aberration: clinico-pathological and genetic characterisation

B. Gonzalez Farre^*, J. E. Ramis-Zaldivar, J. Salmeron-Villalobos, M. Garrido, J. Verdu, N. Garcia, A. Ferrandez, F. Garcia-Bragado, O. Balague, E. Campo, I. Salaverria

^*Hopital Clinic, Pathology, Barcelona, Spain

Background & Objective: Burkitt-like lymphoma with 11q aberration (BLL-11q) is a new provisional category in the 2016 WHO classification. Due to the few published cases it is still controversial if it should be upgraded to a definitive entity. Here we performed a complete study of BLL-11q aiming to improve its knowledge.

Method: A total of 60 cases diagnosed of BL or atypical BL in patients ≤40 years were included. Clinico-pathological and genetical data (immunohistochemical and FISH) were recorded. Copy number (CN) analysis and Target Next Generation Sequencing (NGS) mutational status (including ID3, CCND3, TCF3, MYC and ETS1 genes) were performed in the subset of BLL-11q cases identified.

Results: Ten cases lack MYC translocations and present 11q aberration by FISH. Seven were male and the mean age at diagnosis was 16 years (8-37). The presentation was nodal in 8 cases. All patients received chemotherapy and are alive without disease after 25 months of follow-up. Histologically, all of them mimicked BL but with greater cellular pleomorphism. One case was positive for BCL2 and 3/8 were negative for LMO2. CN array confirmed the presence of alteration of the 11q arm with different patterns in all cases (Range 2-15, Mean alterations 6.85). Most recurrently mutated genes in the 9 cases analysed by target sequencing NGS analysis were MYC, BTG2 and ETS1. Any case harboured mutations in ID3, CCND3 or TCF3.

Conclusion: In our series nodal involvement is frequent in BLL-11q cases and the prognosis is good. 11q alteration pattern is wider than previously described and BL-related mutations are not present.

OFP-01-011

Three cases of Epstein-Barr virus-positive plasmacytoma in immunocompetent patients: a diagnostic dilemma

L. He^*, J. Chen, Z. Li, X. Fan

^*Nanjing Drum Tower Hospital, Dept. of Pathology, People's Republic of China

Background & Objective: By literature review, plasmacytomas arising in immunocompetent patients are rarely associated with Epstein-Barr virus (EBV) infection. EBV-positive plasmacytoma may cause a diagnostic dilemma as it may morphologically and phenotypically overlap with a clinically aggressive plasmablastic lymphoma (PBL).

Method: Three cases of EBV-positive plasmacytoma in immunocompetent status were retrospectively reviewed in this study followed at the Affiliated Hospital of Nanjing University, Nanjing Drum Tower Hospital between January 2008 and March 2018 (two cases of extramedullary plasmacytomas, one case of solitary plasmacytoma of bone). We summarized the available ancillary studies including pre-existing H&E-stained tissue sections, immunohistochemistry, in situ hybridization, molecular analysis, radiological findings and laboratory results upon diagnosis.

Results: Microscopically, these tumours were characterized by proliferation of mature differentiated plasma cells in a diffuse and sheet pattern, which were diffusely positive for EBV encoded RNA (EBER) by in situ hybridization. The neoplastic plasma cells were positive for CD138 and CD38 while Ki67 proliferation index ranges from 2%-20%. The plasma cells were clonal and exhibit light chain restriction on immunohistochemical staining for kappa and lambda light chains. All the three patients were alive with no evidence of disease at last follow up.

Conclusion: EBV-positive plasmacytomas in immunocompetent patients can have a lot of morphological and phenotypical overlaps with PBL. Comprehensive clinical findings, morphological and phenotypical investigation may contribute to a specific diagnosis.

OFP-01-012

Assessment of CD34-positive blasts in bone marrow core biopsy: inter-observer agreement study

E. E. Torlakovic^*, K. R. Calvo, T. I. George, E. Hyjek, S.-H. Lee, J. Mazur, E. Sabattini, L. Saft, A. Tzankov, A. Porwit

^*Royal University Hospital, Pathology and Laboratory Medicine, Saskatoon, Canada

Background & Objective: A value of immunohistochemistry (IHC) in the assessment of CD34+ cells in the bone marrow biopsy (BMBx) is well established. Various protocols for the IHC protocols, different cutoff points for the readout of stained slides, and various statistical methods for analysis of readout results were published. Our study specifically addressed one component of this method, namely inter-observer agreement in percent of CD34-positive cells consistent with blasts. This study was performed by the working group of the International Council for Standardization in Haematology (ICSH).

Method: 110 CD34 IHC slides were included with equal representation of cases in the following diagnostic groups: <5%, 6-9%, 10-19%, and ≥20%. Eight expert haematopathologists were asked to determine the percent of CD34+ cells.

Results: Several different methods were applied for the readout of CD34 IHC slides. Although there was a significant correlation between all observers (Kendall W=0.441), Kappa-value was mostly poor and varied from 0.174 to 0.557. SD and CV of each individual samples were not dependent on the CD34 counts. Congruency of CD34 diagnostic group assignment was: all in one for 11%, all in 2 for 68%, all in 3 for 31%, and all in four for 2%.

Conclusion: Experienced haematopathologists use different methods for readout of CD34 IHC slides and showed poor kappa for classifying patients into different diagnostic groups. These results call for harmonized, evidence-based methods for the readout of CD34 IHC slides as well as for reassessment how the CD34 IHC readouts should be used in the work up of haematological malignancies (e.g. MDS).

OFP-01-013

Pyrosequencing analysis of KRAS, NRAS and BRAF in pancreatic adenocarcinoma, PanIN precursor lesions and normal pancreatic tissue

R. Jouini^*, M. Ferchichi, F. Khanchel, W. Koubaa, I. Helal, O. Khayat, A. Chadli-Debbiche, E. Ben Brahim

^*Habib Thameur Hospital, Pathology, Tunis, Tunisia

Background & Objective: Pancreatic cancer has a high mortality rate and forms the 7th cause of cancer deaths. Histologically, 90% of pancreatic tumours are pancreatic ductal adenocarcinoma (PDAC). Conventional PDAC mainly originates from pancreatic intraepithelial neoplasia (PanIN) and results from accumulation of genetic alterations. The aim of this study was to analyze the genetic status of KRAS, NRAS and BRAF on a series of normal pancreatic tissue, PanIN and PDAC.

Method: We analyzed mutation status of codons 12, 13, 59, 60, 117 and 146 of KRAS and NRAS; and codon 600 of BRAF; using pyrosequencing via a Pyromark Q24 in 25 normal pancreatic tissues, 25 pancreatic intraductal neoplasia (PanIN), and 39 PDAC. These samples were prepared using an enrichment method via 4 mm punch macrodissection of formalin-fixed paraffin-embedded (FFPE) tissues.

Results: There was a statistically significant progressive increment (p < 0.001) in the percentage of mutated cases through normal pancreas (8%), PanIN-1A (28.6%), PanIN-1B (33.3%), PanIN-2 (60%), and PanIN-3 (85.7%) to PDAC (94.8%). These mutations were arising in codons 12 and 61 of KRAS and in codon 600 of BRAF. Most frequent mutations were G12D (46%), G12A (23%), and G12V (18%) of KRAS. No mutations were found in codons 13, 59, 117, and 146 of KRAS or in codons 12, 13, 59, 61, 117, and 146 of NRAS.

Conclusion: Our study supports the model progression of PanIN to PDAC. We found a slight difference in predominant mutation subtypes; which suggest an ethnic role in pancreatic carcinogenesis. Further studies on larger Tunisian series should be performed to confirm our results.

OFP-01-014

Detection of NAB2-STAT6 gene fusions in solitary fibrous tumour by targeted RNA-seq

J. Diaz-Martin^*, E. Aguado, M. Biscuola, M. Delgado, M. Hernández-Barrera, D. Marcilla, J. Martín-Broto, E. de Alava

^*IBiS-HUVR, Molecular Pathology. Lab203, Sevilla, Spain

Background & Objective: Solitary fibrous tumour (SFT) is a rare mesenchymal neoplasm presenting three pathologic variants: typical (TSFT), malignant (MSFT) and dedifferentiated (DDSFT), the latter with a worse prognosis. An intrachromosomal fusion between NAB2 and STAT6 is the defining driving event. These genes lye adjacent in the genome hindering FISH analyses, but nuclear STAT6 expression is consistently detected by IHC. We evaluated targeted RNA-seq performance in detecting NAB2-STAT6 fusions and investigated the association between fusion and histological variants.

Method: We used Archer™ FusionPlex™ Sarcoma Panel for fusion transcripts detection in a series of 56 SFT comprising 22 TSFT, 31 MSFT and 3 DDSFT. IHC for STAT6 expression was performed in a subset of 25 cases. Molecular findings were correlated with pathological features.

Results: STAT6 nuclear staining was observed in 22 cases and SFT fusion transcripts were identified in 21 cases, thus achieving 95% sensitivity for detection of SFTs predicted by IHQ. No fusion transcripts were detected in two IHC negative samples, but SS18-SSX6 fusion (pathognomonic of synovial sarcoma) was identified in the remaining IHC negative case. The most frequent fusion variants in the whole series (n=56) were NAB2ex6-NAB2ex16 (18 cases) and NAB2ex4-STAT6ex2 (16 cases). Any correlation was found between fusion variants and histopathology. Interestingly, no fusion was detected in 2 out of 3 DDSFT.

Conclusion: Targeted RNA-seq detects with high accuracy different variants of NAB2-STAT6 fusion which are not related to different histology. Targeted RNA-seq could be useful when SFT diagnosis is uncertain and may prevent misdiagnosis of other mesenchymal tumours expressing STAT6 protein.

OFP-01-015

Intravascular large B-cell lymphoma (IVLBCL) – a case presenting with anemia, thrombocytopenia and a two-year history of a difficult to classify tremor

R. Rottscholl^*, B. Ritter, S. Tebbe, B. Ruten, I. Berger

^*Klinikum Kassel, Institute of Pathology, Germany

Background & Objective: Intravascular large B-cell lymphoma (IVLBCL) is a rare aggressive entity with a broad spectrum of clinical symptoms

Method: We present a case of 72-year old female with a 2-week history of physical decline. She further reported on an increasing tremor which started to develop two years before. Laboratory testing revealed a normochromic normocytic anemia with Hb of 8.2 g/dl, thrombocytopenia with 47,000/μl and elevated LDH of 1018 U/l. A bone marrow aspirate was unremarkable. The CT scan showed a splenomegaly. Since a haematologic malignancy was suspected the spleen was removed for diagnostic reasons. The 1020 g splenectomy specimen showed a pronounced extension of the red pulp with moderate siderosis. In the adjacent soft tissue an atypical lymphoid infiltrate composed of large- and medium-sized tumour cells located mainly in small sized vessels was noted. Immunohistochemical characterization revealed a CD20+, CD79a+, PAX5+, MUM1+, CD5+, IgM+, bcl2+, bcl6+, CD10–, CD30–, CD23–, Cyclin D1– phenotype and a Mib1 proliferation index of greater than 95 percent, thus the diagnosis of IVLBCL was made.

Results: A six-cycle chemotherapy consisting of vincristine, prednisolone, cyclophosphamide and doxorubicin in a reversed CHOP regimen combined with eight-cycles of Rituximab was administered. During the first cycle of chemotherapy the patient recovered, the Hb returned to normal and the tremor improved and finally dissolved.

Conclusion: A complete neurological assessment performed 3 months after completion of the chemotherapy was unremarkable. The most recent follow-up, 2.5 years after diagnosis, did not show signs of a relapse and the patient reported well-being.

Sunday, 9 September 2018, 17:15 - 19:15, Room A3

OFP-02 | Digestive Diseases Pathology - Liver / Pancreas

OFP-02-001

Long-term survivors of pancreatic cancer exhibit a potent anti-tumoural immune response

M. Wartenberg^*, J. Brugger, E. Vassella, M. Worni, B. Gloor, E. Karamitopoulou-Diamantis

^*University of Bern, Institute of Pathology, Switzerland

Background & Objective: Tumour microenvironment (TME), especially immune cells, modulate cancer progression and pose promising novel therapeutic targets. However, their influence on tumour characteristics and clinical outcomes in pancreatic ductal adenocarcinoma (PDAC), a neoplasm considered highly immunosuppressive, is ill defined.

Method: Three well-characterized PDAC-cohorts, surgically resected with curative intent and composed of long-term survivors (LTS, n=30, overall survival (OS) >60 months), medium-term survivors (MTS, n=40, OS 12-60 months), and short-term survivors (STS, n=40, OS 3-12 months), were included. An integrative tumour analysis was carried out by immunophenotyping (CD3, CD4, CD8, CD20, Foxp3, dendritic cells, iNOs, CD163, RHAMM, MHC1, PD-L1) and next-generation sequencing. Results were correlated with clinico-pathologic characteristics, including tumour budding.

Results: The TME of LTS exhibited numerous CD3+, CD4+ and CD8+ T-cells, and CD20+ B-cells with frequent presence of tertiary lymphoid tissue (TLT), was enriched with iNOS+ M1-macrophages and dendritic cells, and scarce of Foxp3+ Tregs, and CD163+ M2-macrophages. Moreover, LTS displayed no PD-L1 expression, were less frequently RHAMM-positive, and showed the highest MHC1 positivity. STS presented an immunosuppressive TME, rich in Foxp3+ Tregs and CD163+ M2-macrophages, and poor in T- and B-cells, while MTS lied in-between. On genomic level, LTS displayed low mutation frequency in common cancer genes, with significantly less CDKN2A and SMAD4 alterations, and were characterized by significantly lower tumour budding.

Conclusion: Different immune host responses correlate with different molecular and morphological tumour characteristics, affecting cancer progression in PDAC. A combination of tumour-related and host-related microenvironmental features confers a significant survival advantage in PDAC-patients.

OFP-02-002

Critical role of the ECM-molecule Tenascin C for the viability of activated pancreatic stellate cells in pancreatic ductal adenocarcinoma

B. Wingerath^*, I. Zeinert, M. Wirth, I. Esposito

^*University Hospital Düsseldorf, Pathology, Germany

Background & Objective: Pancreatic ductal adenocarcinoma (PDAC) possibly develops from acinar-to-ductal metaplasia (ADM) and is accompanied by an abundant fibrotic reaction rich in extracellular matrix (ECM) molecules. Activated pancreatic stellate cells (aPSC) secrete a variety of signalling and ECM molecules, including Tenascin C (Tnc), thereby modulating tumour microenvironment and promoting epithelial to mesenchymal transition (EMT). Here, we aim at investigating the relevance of Tnc in epithelial-stromal interaction in a PDAC mouse model.

Method: PSC isolated from wildtype and Tnc-knock-out (Tnc-/-) mice were compared concerning their activation status (α-SMA, fibronectin) and EMT promoting cytokines (IL-6, TGF-β) by qPCR. Cancer cells isolated from p48Cretg/+;LSL-KrasG12D/+;p53flox/flox(KPC);Tnc+/+ and KPC;Tnc-/- mice were tested for proliferation and adhesion. Expression levels of ADM markers (Mist1, Ptf1a, Sox9, Ck19) were analysed in pancreatic tissue of KPC and KPC;Tnc-/- mice by qPCR. 3D co-cultures of aPSC from Tnc-proficient and deficient mice with Tnc+/+ cancer cells were established and viability was measured.

Results: Tnc+/+ and Tnc-/- aPSC did not show difference in their activation status or cytokine expression. Moreover, no differences were found regarding proliferation and adhesion of isolated cancer cells or expression of ADM markers in pancreas tissue of KPC;Tnc+/+ and KPC;Tnc-/- mice. Remarkably, in 3D co-cultures, Tnc-/- aPSC displayed significantly increased viability compared to Tnc+/+ aPSC (p = 0.04).

Conclusion: In conclusion, Tnc influences the viability of aPSC in a PDAC-like in vitro scenario, suggesting a pivotal role of this protein in a relevant biologic feature of aPSC in vivo.

OFP-02-003

Morphology and immunohistochemistry predict two unique basal molecular subtypes in pancreatic ductal adenocarcinoma

S. N. Kalimuthu^*, G. Wilson, K. Ng, R. Vajpeyi, S. Gallinger, F. Notta, R. Chetty

^*University Health Network, Anatomical Pathology, Toronto, Canada

Background & Objective: Recently, transcriptional analyses have identified several distinct molecular subtypes. However, to date, a morphological analysis of these molecular subtypes has not been performed. Herein, we investigated specific morphological features and immunophenotype associated with distinct molecular subtypes of PDAC.

Method: We profiled gene expression of 79 primary PDAC specimens from University Health Network (UHN) using RNA sequencing. Gene expression data was deconvoluted using non-negative matrix factorization (NMF), to distinguish tumour and stromal gene expression signatures, resulting in 2 molecular subtypes (basal and classical). The histology of all cases were reviewed and IHC panel incorporating genes enriched in the different subtypes were performed (Basal= CK5, p63, p40, CK14; classical= MUC5AC). IHC was quantified based on proportion of positive tumour cells and scored as 0%, <25% 25-49%, 50-75% and >75%.

Results: Classical subtype (N=59; 75%) uniformly showed a glandular morphology. The basal subtype (N=20; 25%) displayed an array specific histological patterns present in >40% tumour. All basal tumours showed staining in 3/> basal markers and can could be further subdivided into 2 groups based on the % of staining (Group 1=<50% in <3 basal IHC; Group 2= >50% in 3/> basal IHC). Interestingly, this group also showed CK14 selectively staining the leading edge cells, suggesting a potential role for “collective invasion” in PDAC. All classical cases were negative for basal markers and showed variable staining of MUC5AC.

Conclusion: This is the first study to correlate morphology and immunohistochemistry to specific molecular subtypes of PDAC. Additionally, we have identified 2 distinct basal molecular subtypes. However, presently the clinical significance of these subgroups is not known.

OFP-02-004

Keratin 7 expression in hepatic cholestatic diseases

C. Michaelides^*, S. Sakellariou, I. Vlachogiannakos, D. Tiniakos, I. Delladetsima

^*1st Department of Pathology, Medical School, National and Kapodistrian University of Athens, Laiko General Hospital of Athens, Greece

Background & Objective: We aimed to evaluate keratin 7 (K7) immunohistochemical expression in cholestatic liver disease of variable aetiology in relation to bile duct loss, fibrosis stage, bilirubinostasis and serum biochemistry.

Method: K7 expression was assessed and semiquantified in liver biopsies from 103 patients [males 41%/females 59%, mean age ±SD 53±16 years] with bile duct obstruction/destruction (BDO/D) (58%) [partial 55/60 (91%), complete 5(9%)] or parenchymal cholestasis (P-CH) (42%) [acute hepatitis-AH 19(44.2%), pure/mixed cholestasis (P/M-CH) 24(55.8%)].

Results: K7 expression was detected in hepatocytes in 87/103 (84.5%) cases. It was more frequent in BDO/D-CH [55/60 (91.7%) vs P-CH 32/43 (74.4%), p=0.026] with no statistical difference among the subgroups of each category, including zonal distribution pattern with the exception of zone 1 extensive positivity in P/M-CH (6/24, 25%) vs AH (0/19) p=0.027. It also correlated with bile duct loss (p=0.0046) with more extensive zone 1 expression in 15/38 cases (39.5%) vs 8/65 (12.3%) with intact bile ducts (p=0.003). There was no correlation with fibrosis stage or bilirubinostasis besides more frequent panzonal K7 expression in severe bilirubinostasis (56.3%) compared to mild/moderate (25%). K7 expression was negatively correlated with lower levels of direct bilirubin (p=0.047), AST(p<0.001) and ΑLT(p=0.012), while there was a positive correlation trend with γGT values (p=0.074) but no correlation with ALP.

Conclusion: K7 hepatocyte expression is a sensitive cholestatic marker almost constantly present in cholestatic liver diseases. It predominates in BDO/D showing a strong association with bile duct loss. K7 expression does not reflect the severity of liver biochemical profile indicating differences in pathogenetic mechanisms.

OFP-02-005

Necroptosis is associated with a better survival in intrahepatic cholangiocarcinoma

D. Sacchi^*, U. Cillo, S. Sarcognato, E. Gringeri, L. Fabris, M. Di Giunta, L. Nicolè, V. Guzzardo, M. Guido

^*University of Padova, Pathology, Italy

Background & Objective: Intrahepatic cholangiocarcinoma (iCC) has a poor prognosis and few therapeutic options. Necroptosis is a programmed cell-death pathway, which depends on several signaling proteins among which the Receptor-interacting Protein Kinase-3 (RIPK3) activates the necroptosis executioner Mixed Lineage Kinase domain-like (MLKL). In turn, RIPK3 may be activated by RIPK1. By the assessment of the necroptotic pathway protein expression, triggering the necroptosis could be very important in cancer treatment. The expression of RIPK3, MLKL and RIPK1 has not yet been investigated in iCC; therefore, the aim of this study was to assess their immunohistochemical expression and their relationship with patient survival in a cohort of iCC.

Method: RIPK3, MLKL and RIPK1 expression was assessed in 61 paraffin-embedded samples obtained from resected iCC patients. Immunostaining was semi-quantitatively scored by a four-tier scale based on the percentage of positive cancer cells as follows: 0 = <5%, 1+ = 5-30%, 2+ = 31-60%, and 3+ = >60%.

Results: The highest percentage (3+) of RIPK3 was found in 52.4% of cases, MLKL in 41% and RIPK1 in 23.8% and it was associated with a significant decrease of perineural invasion and lymph nodes metastasis (the latter was related only to RIPK3). A diffuse expression of RIPK3 and RIPK1 was related to an improvement of the overall (p=0.01 and p=0.02, respectively) and disease-free (p= 0.01 and p= 0.02, respectively) survival.

Conclusion: Overexpression of RIPK3 and RIPK1 is related to a better prognosis in iCC, which opens the way to new therapeutic options.

OFP-02-006

Lysyl oxidase-like protein 2 in cholangiopathies

M. Pollheimer^*, S. Racedo, A. Mikels-Vigdal, C. Bowlus, C. Lackner, T. H. Karlsen, J. R. Hov, S. K. Lyman, J. Adamkewicz, V. Smith, E. Moreau, T. J. Eide, T. Stojakovic, R. E. Stauber, M. Trauner, P. Fickert

^*Institute of Pathology, Medical University of Graz, Austria

Background & Objective: The lysyl oxidase-like protein 2 (LOXL2) promotes stabilization of the extracellular matrix, cell growth and cell mobility. We aimed to (i) identify stimuli of LOXL2 in cholangiopathies, (ii) characterize the effects of LOXL2 on biliary epithelial cells’ (BECs) barrier function, (iii) compare LOXL2 expression in PSC, PBC, and disease controls, and (iv) to determine LOXL2 expression and cellular sources in 4 mouse models for cholangiopathies.

Method: Murine BECs were challenged with triggers of cellular senescence, hypoxia, Abcb4-/- mouse bile and chenodeoxycholic acid (CDCA) and investigated for LOXL2, SNAIL1 and E-cadherin expression and transepithelial electrical resistance (TEER) with and without LOX-inhibition. In vivo, LOXL2 expression was studied in PSC livers, and controls and mouse models. We compared LOXL2 serum levels in PSC, SSC, PBC patients, and controls.

Results: Cellular senescence, hypoxia, Abcb4-/- bile and CDCA induced LOXL2 and SNAIL1 expression, repressed E-cadherin expression, and significantly reduced TEER in BECs. All of the pathological changes could be recovered via pharmacological LOX-inhibition. Mouse models showed induced LOXL2 expression in the portal region and in association with ductular reaction. LOXL2 serum levels were significantly elevated in patients with cholangiopathies. In PSC, LOXL2 expression was located to periductal onion skin-type fibrosis, ductular reaction, Kupffer cells, and fibrotic septa. In PSC, LOXL2 overexpression was paralleled by E-cadherin loss in BECs from medium-sized bile ducts.

Conclusion: Reactive BECs produce LOXL2, resulting in increased tight junction permeability, which can be ameliorated by pharmacological LOX-inhibition in vitro. Reactive BECs, portal myofibroblasts, and Kupffer cells are the main sources of LOXL2 in cholangiopathies.

OFP-02-008

Hepatocyte transporters expression in hepatocellular adenoma subtypes and focal nodular hyperplasia helps to understand their imaging at Gd-EOB-DTPA magnetic resonance imaging

A. Sciarra^*, S. Schmidt, A. Pellegrinelli, M. Maggioni, C. Cigala, G. Bulfamante, G. Viale, S. Bosari, P. Bioulac-Sage, C. Sempoux

^*Lausanne University Hospital, Switzerland

Background & Objective: GdEOBDTPA enhanced magnetic resonance imaging (MRI) has simplified the diagnosis of focal nodular hyperplasia (FNH) vs. hepatocellular adenoma (HCA) (91% specificity, 92% sensitivity), but the ability of this technique to clearly distinguish the different HCA subtypes is more controversial. Aim of this study was to investigate the expression of hepatocyte transporters (HTs) (OATP2/8, MRP2, MRP3) involved in GdEOBDTPA pharmacodynamics in a large series of FNH and subtyped HCA.

Method: We semiquantitatively scored the immunohistochemical expression of OATP2/8, MRP2 and MRP3 in resected FNH (n=40) and HCA (n=54). From the results of this first step of our study, we further validated our working hypothesis in a supplementary set of FNH (n=7) and HCA (n=10) with GdEOBDTPA imaging data.

Results: All FNH showed consistent expression of all three HTs. HNF1a-inactivated-HCA (H-HCA, n=24) and inflammatory HCA (I-HCA, n=15) subtypes were characterized by a loss of OATP2/8 expression, predictive of no uptake of GdEOBDTPA, as opposed to beta-catenin-activated-HCA (B-HCA, n=11) and HCA with malignant transformation (n=4) (p<0.01). The latter entity also showed an overexpression of MRP3 (p<0.01), predictive of a faster efflux of GdEOBDTPA. At imaging, on the validation set, FNH and HCA uptake of GdEOBDTPA was congruent with tissue expression of HTs, with H-HCA and I-HCA showing no GdEOBDTPA uptake, by contrast to B-HCA and FNH.

Conclusion: Tissue expression of HTs in FNH and HCA subtypes correlates with hepatocyte GdEOBDTPA uptake at MRI. GdEOBDTPA uptake pattern helps in distinguishing H-HCA and I-HCA lacking typical features at nonhepatospecific MRI from B-HCA and HCA with malignant transformation.

OFP-02-009

Pre-operative diagnosis of pancreatic cystic lesions: value of molecular analysis of cytologic samples

L. Haeberle^*, L. Frohn, W. Goering, N. Pomjanski, M. Schramm, I. Esposito

^*Institute of Pathology, Düsseldorf, Germany

Background & Objective: The spectrum of pancreatic cystic lesions ranges from benign to malignant lesions. Cytology is increasingly performed, but results are often inconclusive. Molecular testing of cytologic samples could possible increase pre-operative diagnostic accuracy. The aims of this study were to evaluate the diagnostic accuracy of pre-operative cytology and to assess the value of molecular analysis.

Method: 52 surgically resected pancreatic lesions with pre-operative cytology were analyzed retrospectively. 15/52 cases (28.8%) were excluded, as lesions were non-cystic (10/52; 19.2%) or had biliary origin (5/52; 9.6%) at final diagnosis. Molecular analyses (DNA cytometry/FISH/GNAS sequencing/NGS panel sequencing) were performed in 14/37 cases (37.8%).

Results: At final diagnosis, 28/37 cases (75.7%) were intraductal papillary mucinous neoplasms (IPMN). Additionally, two pancreatic ductal adenocarcinomas, one intraductal tubulopapillary neoplasm, one solid pseudopapillary neoplasm, one mucinous cystic neoplasm, one serous cyst adenoma, one pyloric gland adenoma, one non-neoplastic cyst and one inflammatory pseudocyst were found. Correct diagnosis was possible by cytology alone in 18/37 cases (48.6%). Indication for surgery was correct in 30/37 cases (81.1%). Molecular analysis helped establish a correct diagnosis or indication for further treatment in 9/14 cases without certainly positive cytologic diagnosis (64.3%). In 17/37 cases (46%), (further) molecular analysis could have supported 'suspicious'/'equivocal' cytological diagnosis or confirmed neoplasia in cytologically negative diagnosis.

Conclusion: Our preliminary results underline the need to increase pre-operative diagnostic accuracy in pancreatic cystic lesions, which can potentially be achieved by molecular analysis. However, this needs to be confirmed in a prospective larger cohort.

OFP-02-010

ROS1, ALK, MET and HER2 rearrangements and or amplifications in a series of biliary tract carcinomas

J. Augustin^*, C. Gabignon, A. Scriva, O. Scatton, F. Paye, P. Cervera, D. Wendum

^*Pitié Salpétrière, Pathology, Paris, France

Background & Objective: Biliary tract carcinomas (BTC) are aggressive carcinomas associated with a poor prognosis and no alternative treatment but surgery. In this context, it is urgent to find targetable molecular alterations.

Method: Using a fluorescent in situ hybridization assay, we retrospectively evaluated the frequencies of ROS1, ALK, MET and HER2 rearrangements and or amplifications in a series of 138 BTC (62 intrahepatic cholangiocarcinomas (CC), 29 hilar CC, 15 common bile duct CC, 32 gallbladder adenocarcinomas). ROS1, ALK, MET and HER2 immunostaining was performed together.

Results: We detected HER2 amplifications in 2% (1/62) of intrahepatic CC and in 16% (5/32) of gallbladder adenocarcinomas. Anti-HER2 immunostaining was strongly positive in these 6 cases. We detected 1 MET amplification in the whole series. This case was an intrahepatic CC and was associated with a strong anti-MET immunostaining. We did not detect any other targetable molecular alterations using our panel of probes against ROS1, ALK, MET, HER2. Particularly, hilar and common bile duct CC showed no targetable molecular alteration. We observed several chromosomic alterations suggestive of chromosomal instability in 12% of BTC. Interestingly, 5 cases (all intrahepatic CC) harbored a centromeric alpha-sequences amplification.

Conclusion: HER2 amplifications are recurrent molecular alterations in BTC and seem to be more frequent in gallbladder adenocarcinomas. Immunostaining seems to be performant to detect these cases in routine practice. MET amplifications seem to be rare events. Nevertheless, due to a low rate of targetable molecular events detected in this series, we could not perform any survival analysis and this would require a larger series.

OFP-02-011

Evaluation of necroptosis related genes RIPK1, RIPK3 and MLKL-p immunogenicity in hepatocellular carcinoma

L. Nicolè^*, T. Sanavia, R. Cappellesso, V. Maffeis, V. Guzzardo, C. M. Radu, M. Guido, G. Zanus, A. Fassina

^*University of Padova, Medicine, Italy

Background & Objective: Necroptosis is a form of programmed necrosis. When necroptosis occurring in cancer, dispersed tumoural elements may contribute to boost the immune response. Receptor-interacting protein kinases 1 and 3 (RIPK1 and RIPK3) and the mixed-lineage kinase domain-like protein (MLKL) are the main elements composing the subcellular pathway that realizes necroptosis. Aim of this study was to assess expression of RIPK1, RIPK3 and phosphorylated MLKL in a cohort of HCC patients and their correlation with infiltrating CD8+ T-cells and clinical follow-up data.

Method: RIPK1, RIPK3 and MLKL-p expression was assessed with immunohistochemistry (IHC) in 83 FFPE samples of resected HCC patients. Expression was evaluated on a 4-tired scale. Tumoural and peritumoural infiltrating CD8+ T cells were automatically assessed on digitized sections. Co-localization of necroptotic factors was verified by multiplex imaging. Wilcoxon Rank Sum test and survival analysis were applied to: 1) compare the correlation between RIPK1, RIPK3, MLKL-p and their combination with T cell-infiltration; 2) evaluate the prognostic impact of these necroptotic kinases in HCC. Results were compared with those obtained from computational analysis of RNA-seq data in 373 HCC patients from TCGA.

Results: RIPK1, RIPK3 and MLKL-p expression are significantly associated with tumoural but not peritumoural CD8+ T-cells infiltration (p-values < 6e-05 and > 0.4, respectively). By combining the IHC scores of the three kinases, the strength of the association with tumour infiltrating CD8+ T-cell increases (p-value 2.6e-09). Results are confirmed by TCGA RNAseq data.

Conclusion: Necroptosis occurs in a subsets of HCC patients and it is correlated to the entity of infiltrating CD8+ T-cells.

OFP-02-012

Immunohistochemical staining patterns of the PDAC stroma and their prognostic implications

T. Oguzsoy^*, P. Bagci, G. Akbas

^*Marmara University, Pathology Dept., Istanbul, Turkey

Background & Objective: Our aim is to evaluate the relationship between stromal markers (Galectin-1, SMA, Collagen Type IV) and histopathological parameters of pancreatic ductal adenocarcinoma (PDAC), to investigate the role of these parameters in predicting the prognosis, and to show their relationship with response to therapy, if any.

Method: 76 consecutive resections diagnosed as PDAC, were immunostained with SMA, Collagen Type IV and Galectin-1 antibodies. Statistical analysis was performed over the semiquantitative results of immunhistochemistry (IHC).

Results: Mean survival was 17.9 months (1,6-75 months). M/F = 48/28. Male gender, high grade, and surgical margin positivity were independent poor prognostic factors. There was a significant correlation between high SMA expression, and presence of angioinvasion (p= 0.006). High Galectin-1 immunreactivity had an effect over survival independent of the N stage (p= 0.035). Although not statistically significant, Collagen Type IV high-reactive cases were found to have better prognosis (HR= 0.595), independent of the pathological stage.

Conclusion: This is the first microscopy-based study to show relationship between Collagen Type IV and PDAC. Collagen Type IV can also be included in the study objectives during antiangiogenic and antistromal treatments are being developed. SMA IHC might be helpful in determining the risk of angioinvasion and capacity of systemic spread. Unlike the literature, we showed high stromal Galectin-1 expression is a good prognostic factor independent of the pathological stage. Our findings suggest, the stroma is trying to limit the spread of the tumour.

Sunday, 9 September 2018, 17:15 - 19:15, Barria

OFP-03 | Dermatopathology

OFP-03-001

25 kgy radio-sterilised human skin graft shows effective skin regeneration in nude mice

J. Tomaz De Miranda^*, F. De Andrade Bringel, V. Protocevich, A. P. Pereira Velosa, V. Capelozzi, M. B. Mathor, W. R. Teodoro

^*Faculdade de Medicina / USP, Ciências Medicas / FMUSP, São Paulo, Brazil

Background & Objective: There has been a growing interest in radio-sterilized skin grafting, especially in extensive and deep burns. Our purpose was to evaluate the histoarchitecture of the human skin graft irradiated during the tissue repair process in NUDE mice.

Method: Nude mice received skin grafts irradiated with dose at 25 kGy and 50 kGy and non-irradiated, submitted to euthanasia on the 3rd, 7th and 21st days after surgery. Morphometric evaluation was performed to quantify keratinocytes, fibroblasts, defense cells and blood vessels. Expression of human type I collagen, mouse type I and III collagen, identified by immunofluorescence and histomorphometry.

Results: Histological results showed that irradiated human skin has influence on cell growth. At 25 kGy, on the 3rd there was an increase in fibroblasts (41.53±8.81vs21.68±4.90) and inflammatory cells respectively on 3rd and 7th (115.8±16.73vs11.17±6.56 and 144.1±19.15vs70.17±23.62) in relation to non-irradiated; on the 21st the keratinocytes increased in relation to the non-irradiated (260.9±69.46vs138.0±40.12) and 50 kGy (260.9±69.46vs0.0). On 21st, the three groups presented incorporation of the human graft, being 25 kGy better to skin regeneration with lower inclusion of the human collagen I (6.31±4.34vs43.20±18.78) and greater mouse collagen III (34.60±10.28vs22.48±10.66) in relation to non-irradiated.

Conclusion: This study showed that the group irradiated at 25 kGy presented greater cell proliferation and better regeneration, suggesting that this dose is probably more indicated for skin grafting, providing faster and more effective healing.

OFP-03-002

The lupus band test, an uncomplimentary diagnostic tool in the diagnosis of lupus erythematosus

S. Ní Mhaolcatha^*, C. C. Heffron

^*Cork University Hospital, Dept. of Pathology, Ireland

Background & Objective: The lupus band test (LBT) using Direct Immunofluorescence (DIF) is routinely used in the diagnosis of lupus erythematosus (LE) at Cork University Hospital, Cork. However, low positive LBT rates and poor concordance with histological diagnoses have warranted a review of the sensitivity of the LBT in the diagnosis of LE. We undertook a large case study to evaluate the efficacy of the LBT in the diagnosis of LE.

Method: From 2011 to 2017, all cases of DIF requested for the investigation of LE were retrieved and reviewed with key aspects recorded: lupus band test result; DIF detected antibodies; and diagnosis on histology. All skin biopsies sent for DIF had a corresponding skin biopsy sent for histology.

Results: 258 of 947 requests made for DIF were requested for LE. 24 (9.4%) had a positive lupus band test. 16(66.7%) of these cases showed IgG and IgM antibody distribution at the basement membrane zone. This was discordant with histology, as 102 (39.8%) cases were diagnosed with LE on histology, with only 19 of these cases having a positive LBT. The sensitivity and specificity of the LBT was 18.3% and 96.75% respectively.

Conclusion: This study has established that the LBT is not a sensitive diagnostic test in the diagnosis of LE. It is appreciated that DIF is a useful diagnostic tool however it would be a more prudent and cost effective to use DIF when an additional diagnostic tool is required to rule out LE. A case study of this size has not been reported before.

OFP-03-003

PTEN hamartoma of soft tissue: presentation of two cases and a literature review

O. B. Popescu^*, S. Hernández Bonilla, I. de la Peña Navarro, I. Ruz-Caracuel, M. Beato, E. Ruíz-Bravo

^*Hospital Universitario La Paz, Dept. of Pathology, Madrid, Spain

Background & Objective: PTEN gene was isolated and cloned in 1997 and germline mutations have been identified in Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, Proteus syndrome and Proteus-like syndrome. Since then, a variety of vascular anomalies have been reported in these patients. In 2012 a vascular lesion with a distinctive histopathologic feature was described and named phosphatase and tensin homolog (PTEN) hamartoma of soft tissue (PHOST).

Method: We present two cases diagnosed with PHOST in Hospital Universitario La Paz between 2012 and 2018. A 31-year-old female with Cowden syndrome (R233 de novo mutation of PTEN gene) with a lesion in the upper extremity and an 11-year-old male with a lesion in the lower extremity who is being studied for PTEN mutation.

Results: In both patients the lesions of the extremities had the same histopathologic characteristics and were composed of a variable admixture of adipose tissue, abnormal vessels, dense and myxoid fibrous tissue. The tissues appeared mature without cytologic atypia, necrosis or mitosis. The vascular component consisted of thick and thin walled dilated veins and of medium-sized tortuous arteries with smooth muscle hyperplasia. Nerves with periaxonal spindled cell proliferation resulting in onion bulb formation and lymphoid aggregates were observed.

Conclusion: In 2014 PHOST has been included in the International Society for the Study of Vascular Anomalies Classification. It is important to recognize it and the diagnoses should prompt a clinical evaluation and genetic testing for a PTEN mutation. To the best of our knowledge only one case has been published since the original report in 2012.

OFP-03-004

Clinical and molecular heterogeneity in DNA repair diseases predisposing to accelerated ageing: example of Xeroderma Pigmentosum and Cockayne syndrome

H. Yacoub-Youssef^*, I. Krawa, A. Chikhaoui, S. Bouchoucha, M. Zghal, S. Abdelhak, I. Turki

^*Institut Pasteur de Tunis, Tunisia

Background & Objective: Xeroderma pigmentosum (XP) and Cockayne syndrome (CS) are rare autosomal recessive disorders that affect DNA repair system (NER). Clinical and genetic heterogeneity within these pathologies makes genotype-phenotype correlation very difficult. Indeed, the XP is characterised by UV-induced skin dyspigmentation, sunburn, cancers, skin photo-ageing and in some patients, neurological degeneration. However, the CS is characterised by progressive neurological disorder, a progeroid appearance, microcephaly, severe psychomotor delay, and intracranial calcifications. The combined (XP/CS) phenotype, is characterized by severe growth defects, cognitive disability, premature aging, dwarfism, in addition to XP disease. Here we investigate 4 patients with severe clinical phenotype of CS and 2 patients with atypical mild XP phenotype.

Method: Blood were collected and DNA extracted. We carried out mutational analysis through Sanger and target gene sequencing.

Results: We identified a recurrent mutation (p. Tyr200LysfsX12) in ERCC8 gene in patients carrying typical characteristics of CS. This mutation seems to be specific to North African patients. Regarding XP patients, in two siblings, a homozygous variant p. L778P was found in ERCC5 gene, these are the first XPG patients reported in North Africa also.

Conclusion: This study extended the mutation spectrum of rare DNA repair diseases such as XP and CS. Defects in ERCC5 gene remain a paradigm in DNA repair diseases. Indeed, mutations in this gene could result in phenotypes that range from mild XP form to the most severe combined form of XP/CS. Both XPG and XP/CS are models for premature ageing studies, especially for immune system senescence and skin ageing investigations.

OFP-03-005

Is microsatellite-instability a prognostic factor in melanoma patients treated with immune-checkpoint inhibitors?

M. Koeller^*, M. Berger, S. Eder, G. Richtig, E. Richtig, M. Pichler, G. Winter, G. Hoefler, A. Aigelsreiter

^*Medical University Graz, Diagnostic and Research Institute of Pathology, Austria

Background & Objective: To investigate the prevalence of mismatch repair (MMR) deficiency and its correlation with treatment response (TR) and mortality in melanoma patients treated with immune checkpoint-inhibitors.

Method: In this retrospective study we investigated patients who received pembrolizumab, nivolumab or ipilimumab between 2012 - 2015 with melanoma cTNM stage III unresectable (n=1) or IV (n=21). Loss of MMR enzymes MLH1, MSH2, MSH6 and PMS2 was evaluated immunohistochemically. Five melanomas were further tested for microsatellite instability (MSI) and loss of heterozygosity (LOH) using the Promega-MSI-Analysis-System. Samples were classified as MMR deficient only if MSI was confirmed by PCR. TR was measured three and six months after therapy initiation using the immune related response criteria (irRC). Statistical testing regarding correlation of MMR deficiency and LOH status with TR and overall survival was performed using Fisher’s-exact-test and log-rank-test.

Results: None of the 22 patients showed MSI confirmed by PCR. LOH at the marker locus Penta D was detected in 2 of 5 patients (40%). No significant correlation between LOH-status with TR after 3 (p>0.05) and 6 (p>0.05) months was found. LOH-status had no impact on overall survival (p>0.05).

Conclusion: Our pilot study demonstrates that MMR deficiency was suspected immunohistochemically in a few cases but could not be confirmed by MSI testing. LOH was detected in 2 patients, but no correlation with TR or overall survival could be observed.

OFP-03-006

eIF6 is overexpressed in melanoma of the skin and might be a novel therapeutic target

S. Bracic^*, N. Woltsche, S. Krassnig, R. Seeboeck, I. Zalaudek, J. Haybaeck

^*Institute of Pathology, Graz, Austria

Background & Objective: Malignant melanoma (MM) of the skin ranges among the most frequently diagnosed cancer entities. Aim of this study was to determine which eIF subunits are involved in tumourigenesis of melanocytic skin neoplasms and melanoma progression. Therefore, eIF expression in MM was compared to corresponding normal skin tissue and benign naevi.

Method: The immunohistochemical evaluation included 62 patients: 13 MM (primary and recidive) and 49 benign naevi at the Medical University of Graz, Austria. Age at removal of lesion, location, histopathological diagnosis, congenital pattern for naevi, BRAF status for MM and time to recurrence were recorded. For eIF expression, tissue was stained for eIF2α, eIF3p110, eIF3H, eIF4E, eIF4H, eIF5 and eIF6. Based on the IHC results, siRNA knockdown of eIF6 was performed in two metastatic and two non-metastatic MM cell lines and evaluated for cell viability, apoptosis and migration.

Results: Our results demonstrated that in MM of the skin compared to naevi, eIF2α (p=0.013) and eIF6 (p=0.034) were significantly overexpressed. Based on these results, siRNA knockdown for eIF6 was performed in vitro. Successful eIF6 knockdown was confirmed in all cell lines using qRT-PCR. The siRNA mediated knockdown of eIF6 reduced cell viability in all analysed cell lines. Reduction of cell viability was more prominent in the metastatic cell lines than in the non-metastatic ones. Cell migration was only impaired in the metastatic cell lines upon siRNA treatment.

Conclusion: Our preliminary data reveal an important role for eIF6 in the carcinogenesis of MM and a potential novel target for new anti-cancer drugs in MM therapy.

OFP-03-008

Increased SMAD7 expression is associated with tumour aggressiveness and independently predicts poor survival in cutaneous melanoma patients

M. Kaczorowski^*, P. Biecek, P. Donizy, M. Pieniazek, R. Matkowski, A. Halon

^*Wroclaw Medical University, Dept. of Pathomorphology and Oncological Cytology, Poland

Background & Objective: SMAD7 is a key inhibitor of transforming growth factor-β signaling and its involvement in cancer development and progression has been identified in a number of tumour types. The aim was to characterize SMAD7 expression and clarify its clinical significance in skin melanoma.

Method: SMAD7 expression was evaluated by means of immunohistochemistry in formalin-fixed paraffin-embedded tissues of 205 cutaneous melanoma primary tumours. The results were correlated with classical clinicopathological characteristics, including patient survival.

Results: SMAD7 was expressed in melanoma cells, at least weakly, of virtually all tumours (204/205 cases) and the pattern was almost exclusively nuclear. Increased SMAD7 reactivity was most commonly observed in nodular melanomas and coincided with other features of aggressive tumour phenotype, including greater tumour thickness, higher mitotic rate and the presence of ulceration. According to Kaplan-Meier analysis, enhanced SMAD7 expression was correlated with considerably shorter melanoma-specific survival and recurrence-free survival. Prognostic significance of SMAD7 expression was confirmed after adjustment for Breslow thickness, pN status and the intensity of tumour-infiltrating lymphocytes in a multivariable analysis.

Conclusion: Our results indicate that SMAD7, a marker of aggressive tumour behavior and adverse clinical outcomes, plays an important role in melanoma progression. Targeting SMAD7 for therapeutic purposes in cutaneous melanoma merits further investigations.

OFP-03-009

Digital pathology versus light microscopy in evaluation of malignant melanoma

M. Biskup-Fruzynska^*, A. Stanek-Widera, B. Nikiel, D. Lange

^*COI Gliwice, Dept. of Tumour Pathology, Poland

Background & Objective: Malignant melanoma is not the most common skin neoplasm, but it is responsible for the vast majority of skin cancer deaths. Assessment of prognostic factors such as mitotic rate, tumour thickness and surgical margins is crucial for the therapy process. The aim of the study was to compare traditional and digital method in evaluation of histopathological parameters that are prognostically important in malignant melanoma.

Method: We examined 41 cases of malignant melanoma of the skin, diagnosed in 2001-2005. The histopathological slides were scanned and analysed with regard to features such as tumour thickness, mitotic rate per 1 square millimetre and the shortest surgical margin. Scanned slide images were evaluated using the available precise measuring tools. The results were compared with the interpretation of the features in traditional light microscopy.

Results: The use of precise digital measuring instruments caused changes in pT stage in 15% of cases. Mitotic rate was different in as much as 50% of cases: lowered in 20 cases and increased in 2 cases. Minimal changes concerned surgical margins, which varied averagely by 0,11 mm.

Conclusion: The diagnostics of malignant melanoma of the skin basing on the digital images of the scanned slides allows more precise and reproducible method to evaluate the parameters that are prognostically important.

OFP-03-010

Re-excision benign perineural epithelial infiltrates: a pitfall in the assessment of residual carcinoma

O. Neagu^*, M. Farcas, P. I. Stânga, A. Cioroianu, R. Andrei, S. A. Zurac, I. Marinescu, C. Socoliuc

^*Spitalul Clinic Colentina, Pathology, Bucharest, Romania

Background & Objective: Carcinomatous perineural invasion is a sign of aggressive tumour behavior and poor prognosis. Nonetheless, diagnosing perineural invasion can be complicated by benign mimics. Among these, one occurs in re-excision skin specimens and represents perineural infiltration by benign epithelial cells without any perineural spread beyond the previous biopsy site or residual malignant tumour adjacently, possibly explained by reactive eccrine duct regeneration into perineural spaces or displacement of the overlying epidermis.

Method: We present the case of a 66 year old man having undergone an excision and subsequent re-excisions for the treatment of a retroauricular tumour in a three-month interval.

Results: Histologic examination of the first excision specimen revealed a squamous cell carcinoma, grade 2, completely excised with close deep margins. The second surgical intervention revealed an incidental superficial basal cell carcinoma, completely excised and no residual squamous cell carcinoma. The third intervention revealed skin ulceration and small nerve fascicles cuffed by epithelial cells with morphology similar to the perilesional regenerated adnexal epithelium, some located right under the regenerative epidermis suggestive of a continuous lesion. Careful examination of the whole tissue submitted showed no residual tumour cells and permitted establishing the final diagnosis of benign perineural epithelial infiltrates.

Conclusion: Re-excision skin specimens may show benign perineural epithelial infiltrates, mimicking carcinomatous perineural invasion. These have to be carefully evaluated in order to avoid misdiagnosis and unnecessary additional treatment.

OFP-03-011

Hypoxic gene signature of primary and metastatic melanoma cell lines: focusing on HIF1-beta and NDRG-1

M. E. Ercin^*, O. Bozdogan, T. Cavusoglu, N. Bozdogan, P. Atasoy, M. Kocak

^*Karadeniz Technical University, Medical Pathology, Trabzon, Turkey

Background & Objective: Hypoxia is an important microenvironmental factor significantly affecting tumour proliferation and progression. The importance of hypoxia is not well known in oncogenesis of malignant melanoma.

Method: The mRNA expression levels of hypoxic genes in primary and metastatic melanoma cell lines and in primary cell line at experimental hypoxia conditions were evaluated by using real-time PCR. Depend on experimental data, we focused on two gene/protein, Hypoxia-inducible Factor-1 Beta (HIF-1β) and N-Myc Downstream Regulated 1 (NDRG1). The protein expression levels of two proteins were investigated by immunohistochemistry methods, in 16 primary and metastatic melanomas, 10 intradermal nevi, and commercial tissue array comprised of 208 cores, including 192 primary and metastatic malignant melanomas.

Results: The real-time PCR study showed that hypoxic gene expression signature was different between metastatic and primary cell lines. Hypoxic experimental conditions significantly affect hypoxic gene expression signature. In immunohistochemical study, NDRG-1 expression was found to be lower in primary cutaneous melanoma compared to intradermal nevi (p=0.001). In contrast, the cytoplasmic expression of HIF-1β was higher in primary cutaneous melanoma than in intradermal nevi (p=0.001). We also detected medium/strong significant correlations between studied two proteins in the study groups.

Conclusion: This study may show that hypoxic response consists of closely related proteins in more complex pathways. These findings will shed light to hypoxic processes in melanoma and unlock “Pandora’s box” for development of new therapeutic strategies.

Monday, 10 September 2018, 08:30 - 12:00, Room A1

OFP-04 | Digestive Diseases Pathology - GI

OFP-04-001

The consensus molecular subtypes (CMS) and tumour budding: a study on 1525 patients

I. Zlobec^*, A. Trinh, C. Lädrach, H. Dawson, S. ten Hoorn, P. J. K. Kuppen, M. S. Reimers, M. Koopman, C. J. A. Punt, A. Lugli, L. Vermeulen

^*University of Bern, Dept. of Pathology, Switzerland

Background & Objective: In colorectal cancer (CRC), tumour budding is recognized as an important prognostic factor. The molecular profile of tumour buds is consistent with (partial) epithelial-mesenchymal transition and stemness, similarly described in the “mesenchymal” Consensus Molecular Subtype (CMS4), representing a particularly poor prognostic subgroup. Here, we determine the association of tumour budding with CMS classification and prognosis.

Method: The AMC-AJCCII-90 series (n=76, stage II) was evaluated for peritumoural budding on H&E slides. The LUMC (n=470, stage I-IV), CAIRO (n=484, mCRC) and CAIRO2 (n=475, mCRC) cohorts were investigated for intratumoural budding using pan-cytokeratin-stained tissue microarrays. Budding was scored as a count/area, then classified as <5 or ≥ 5 buds. For all patients, CMS classifications were available (gene-expression/immunohistochemistry-based classifiers).

Results: High (≥5) budding predicted worse outcome in multivariate analysis in AMC-AJCCII-90 (p=0.018), LUMC (p<0.0001), and CAIRO (p=0.03), and in univariate analysis in CAIRO2 (p=0.042). Tumour budding counts were significantly higher in CMS4 mesenchymal tumours compared to epithelial CMS2/3 cancers (p<0.01, all), and associated with KRAS/BRAF mutations (p<0.01, all).

Conclusion: Tumour budding is an adverse prognostic factor across all CRC stages and associated with the mesenchymal CMS4 phenotype. KRAS/BRAF mutations are strongly correlated with tumour budding suggesting its involvement in regulation of this phenotype.

OFP-04-002

Assessing the stability of pathologist diagnostic rate over seven years in a cohort of 38,813 colorectal polyp specimens and implications for histomorphology and statistical process control / next generation quality

M. Bonert^*, A. Naqvi, M. Rahman, H. Kazerouni, P. Major

^*McMaster University, Hamilton, Canada

Background & Objective: The objective of this work was to understand the stability of diagnostic bias in colorectal polyps, focused on high grade dysplasia (HGD) and villous morphology (TVA|VA), and how this may impact the utility of statistical process control|next generation quality (SPC|NGQ) for histomorphologic diagnoses.

Method: All colorectal polyp specimens (CRPS) for 2011-2017 in a region were categorized using a previously validated hierarchical free text string matching algorithm. Pathologist diagnostic rates (PDRs) were assessed (1) longitudinally for each pathologist in yearly intervals with control charts (CCs), and with (2) logistic regression (LR).

Results: The study period included 64,115 CRPS. Fifteen pathologists each interpreted >150 CRPS/year in all years and together read 38,813 (range 1335 to 3644). Yearly PDRs compared to each pathologist’s overall PDR showed CC drift/outliers (P<0.05|P<0.001) in HGD (9|2 of 105 pathologists x PDR years), and TVA|VA (24|10 of 105). Few pathologists accounted for many of the P<0.05 outliers; two pathologists accounted for four of the HGD outliers and three pathologists for 15 in TVA|VA. LR confirmed, in the 27 pathologists reading >600 CRPS each (total 52,760 CRPS), that predictors for HGD and TVA|VA included pathologist, clinician, year (all P<0.0001), and hospital (P=0.01).

Conclusion: Pathologists have a mix of (1) drift in their yearly PDRs (that exceeds that expected due to sampling), and (2) PDR stability. The substantial PDR stability supports the hypothesis that histomorphology is amendable to calibration via SPC|NGQ and expert review. Adoption of SPC|NGQ would probably allow pathologists to deliver more uniformity and greater healthcare value, and result in better patient outcomes.

OFP-04-003

Does tumour budding contribute to the molecular classification of colorectal carcinoma?

M. C. Martinez Ciarpaglini^*, S. Oltra Sanchiz, F. Carrasco Bailén, N. Tarazona, C. Mongort, S. Rosello, D. Roda, A. Cervantes, S. Navarro

^*Hospital Clínico de Valencia, Biomedical Research Institute, Pathology, Spain

Background & Objective: The mesenchymal subgroup (CMS4) of the colorectal cancer (CRC) consensus molecular classification is the most aggressive subtype, showing upregulation of genes implicated in epithelial-to-mesenchymal transition (EMT). Tumour budding (TB) represents the histological picture of cells having undergone at least partial EMT. In the base of this knowledge, we aimed to explore the influence of TB in the expression of genes and microRNAs (miRNAs) implicated in EMT and to assess their value as survival predictor factors.

Method: We retrospectively analyzed tumour budding grade in 125 consecutive diagnosed formalin fixed paraffin-embedded (FFPE) colectomy specimens in all stages. The expression analysis of miR200a, miR200b, miR200c, ZEB1 and ZEB2 was made through Quantitative real time-PCR (qRT-PCR) from samples of two different areas: the tumour center and the invasion front with the higher concentration of buds.

Results: We found a significant overexpression of ZEB and a significant reduction of miRNAs in TB areas compared with the center of the tumour. Only the under expression of miR200c and miR200a measured in the TB areas showed a significant correlation with survival. In multivariate analysis of cases in clinical stage I to III, miR200c under expression in TB areas was an adverse tumour-specific survival factor (HR: 0.12, CI 95% 0.03-0.81, p=0.02) independent of clinical stage.

Conclusion: The molecular expression profile in TB areas define a worse prognosis subgroup of cases, suggesting the contribution of these areas to the CMS4 molecular classification. These results highlight the importance of including TB areas in samples for biomarkers evaluation.

OFP-04-004

Tumour budding versus T-cell infiltrates in colorectal cancer: can opposite forces be united?

H. Dawson^*, M. Eichmann, L. Christe, I. Zlobec, A. Lugli

^*University of Bern, Institute of Pathology, Switzerland

Background & Objective: Tumour budding and T-cell infiltrates are well-established prognostic factors in colorectal cancer (CRC), but their value in combination has only rarely been investigated. Here, we examine tumour buds and T-cell infiltrates in CRC each alone and together as a budding/T-cell score (BTS).

Method: This study was performed on a multi-punch tissue microarray containing material from 394 patients with Stage I-IV CRC. Areas from tumour center, front and microenviroment were stained for Pancytokeratin/CD3, Pancytokeratin/CD8 and Pancytokeratin/CD45RO. Tumour buds were scored manually and T-cell infiltrates digitally. Tumour buds, T-cell counts as well as combined BTS were associated with clinicopathological features and overall survival (OS).

Results: Out of the T-cell markers, CD8 and CD3 were markedly superior to CD45RO for predicting clinicopathological features and OS. A higher combined BTS score (Buds/CD8) performed slightly better than budding or CD8/CD3 alone in predicting nodal metastases (p<0.0001, OR 1.466, 95%CI: 1.115-1.928). Out of all scores (budding, T-cells and BTS), only higher BTS (Buds/CD3) was significantly associated with poorer OS on multivariate analysis (p= 0.012, HR 1.218, 95%CI: 1.044-1.419).

Conclusion: Although CD8+/CD3+ T-cells are strongly predictive of tumour biology in CRC, we found a combined BTS to be stronger in predicting survival and certain features with high clinical relevance, such as nodal metastases, in comparison to budding or T-cells alone. Further studies combining the assessment of T-cell infiltrates and tumour budding as markers of opposite forces are necessary to optimize risk assessment of CRC.

OFP-04-005

Profiling lymphocyte and macrophage infiltration in association with tumour budding to personalise stage II colorectal cancer prognosis

I. P. Nearchou^*, C. G. Gavriel, D. J. Harrison, P. D. Caie

^*University of St. Andrews, School of Medicine, United Kingdom

Background & Objective: A growing awareness exists that the tumour microenvironment (TME) contributes to cancer progression. Reporting infiltrating immune cells and tumour buds (TBs) within the TME, has been shown to correlate with clinical outcome. Traditionally these are studied in isolation of each other. The aim of this study is to evaluate the prognostic significance of their association and interaction in patients with stage II colorectal cancer disease (CRC).

Method: Multiplexed immunofluorescence and automated image analysis were used for the quantification of CD3+, CD8+ lymphocytes; CD68+, CD163+ macrophages and TBs, across whole slide images (n=114). Machine learning algorithms were used for feature selection and prognostic risk model development.

Results: A higher number of TBs was correlated with advanced pT stage (P = 0.004). A higher number of CD3+ cells at the invasive margin was correlated with a lower number of TBs (P = 0.03). A higher ratio of CD68+/CD163+ cells at the tumour core was associated with a higher number of TBs (P < 0.0001). A novel prognostic signature, derived from integrating TBs, lymphocytes and their spatial relationship reported a cohort stratification (P < 0.0001) which outperformed the clinical gold standard of pT stage (P = 0.003).

Conclusion: This study provides evidence that the interaction between lymphocytes and TBs holds prognostic significance in stage II CRC and the combination of these features shows a prognostic significance, which exceeds that of each in isolation.

OFP-04-006

Morphological assessment of immune checkpoint expression in colorectal adenocarcinoma

A. Canard^*, A. Scriva, K. Wanherdrick, M. Svrcek, J.-F. Fléjou, A. Duval, P. Cervera

^*Hôpital Saint-Antoine, Pathology, Paris, France

Background & Objective: 40% of patients with mismatch repair-deficient (MSI) tumours benefit from immunotherapy. The establishment of predictors of treatment response and the understanding of the immunomodulation have become a priority. In colorectal cancer, cytotoxic T cells density and location predict better outcome. However, immune checkpoint expression has been shown to be associated to worse prognosis, independently of tumour staging in MSI tumours, challenging the anti-tumoural cytotoxic T cells response in this subset of highly immunogenic colon tumours. Therefore, the purpose of this study is to assess the morphological immune profile counterpart of the transcriptomic analysis, by density and location of known immune key players, taking into account the molecular subtypes of colorectal cancer and the immunecheckpoints.

Method: A well studied population‐based series of 399 colon cancers (184 MSI tumours and 215 tumours without microsatellites instability (MSS)), operated on between 2004 and 2013, is investigated. Tissue microarray (TMA) samples have been collected from the tumour centre (IT), the invasive front (IF) and normal tissue (NT) away from tumour. They were immunostained with cytotoxic and immune modulators antibodies. A software dedicated to TMA morphometric analysis with virtual slides was developped, allowing to study the density of the immunostained cells.

Results: As expected, a significant increase of CD3+ T lymphocytes, cytotoxic T lymphocytes CD8+, Granzyme B+ , memory lymphocytes CD45RO+ is evidenced in MSI colorectal cancer compared to MSS and associated with an increase expression of immunecheck points (PD-L1, PD1, LAG-3) and immune modulators (IDO1).

Conclusion: The next step is to investigate the prognosis impact of these markers and a potential immunoscoring relevance.

OFP-04-007

E-learning for determining the tumour-stroma ratio (TSR) as addition in routine diagnostic pathology; the UNITED study

M. Smit^*, G. van Pelt, A. Farina Sarasqueta, V. Terpstra, J.-F. Fléjou, R. Tollenaar, H. van Krieken, W. Mesker

^*LUMC, Surgery, Leiden, The Netherlands

Background & Objective: The UNITED study (Uniform Noting for International application of the Tumour-stroma ratio as Easy Diagnostic tool) was designed to prepare implementation of the tumour-stroma ratio (TSR) in routine diagnostic pathology. For standardization and to reach consensus an E-learning was developed. TSR is a practical and fast assessment, to distinguish within stage II-III colon cancer (CC) patients, who will likely benefit of adjuvant therapy and who will not.

Method: The online training starts with an instruction movie available via www.watchstroma.com. The E-learning (developed in PathXL) consists of a training and test set, each with 40 CC cases. It is an online tool using digitalised Haematoxylin & Eosin stained sections. To evaluate the reproducibility of TSR scores, inter- and intra-observer agreements will be calculated. After completion of the E-learning, committed pathologists will participate in the prospective study measuring TSR in 1500 patients CC stage II and III.

Results: At this moment colorectal cancer pathologists from more than 10 European countries and 15 centres agreed to participate in the UNITED study. It takes about 45 minutes to complete a set. Eight pathologists tested the E-learning with inter-observer agreements (Kappa-score) between 0.6 and 0.81. The E-learning has become recently available. Based on preliminary results we expect all data to be ready to present at the congress.

Conclusion: Training by using an E-learning tool can result in a highly consistent and standardized method. This has an important effect on the strength of the UNITED prospective trial. Ultimately, this trial will lead to a new biomarker for selecting patients for adjuvant treatment.

OFP-04-009

MicroRNAs as markers of epithelial-mesenchymal transition in colorectal cancerogenesis

B. Rankovic^*, E. Boštjanèiè, M. Žlajpah, N. Zidar

^*Faculty of Medicine, UL, Institute of Pathology, Ljubljana, Slovenia

Background & Objective: MicroRNAs are small, noncoding RNAs that regulate gene expression by posttranscriptional regulation of target genes. miR-200 family (miR-200a/b/c, miR-141, miR-429) has been shown experimentally to regulate epithelial-mesenchymal transition (EMT) in various physiologic and pathologic conditions, including cancer. As EMT is the postulated mechanism of carcinoma development and progression, we analysed the expression of these microRNAs in colorectal cancerogenesis.

Method: We analysed the expression of miR-200 family using quantitative real-time polymerase chain reaction. Forty cases of formalin-fixed paraffin-embedded tissue were included (10 adenomas, 10 malignant adenomas/early carcinomas, 10 cases of carcinoma without nodal metastases and 10 cases of carcinoma with nodal metastases). Cases of carcinoma included both tumour tissue as well as corresponding normal mucosa.

Results: We found down-regulation of the miR-200a/c, miR-141 and miR-429 in carcinoma with nodal metastases compared to carcinoma without nodal metastases. Moreover, miR-200b/c showed up-regulation in malignant adenoma/early carcinoma compared to adenoma and carcinoma with and without nodal metastases. miR-429 showed up-regulation in malignant adenoma/early carcinoma and carcinoma without nodal metastases compared to adenoma.

Conclusion: Down-regulation of the miR-200 family in colorectal carcinoma with lymph node metastases compared to carcinoma without lymph node metastases strongly supports the postulated role of EMT in carcinoma progression and metastasizing. However, our finding of up-regulation of miR-200b/c and miR-429 in malignant adenoma/early carcinoma is not consistent with the postulated role of EMT in the progression of adenoma to malignant adenoma.

OFP-04-010

Somatic copy number alterations as a biomarker of recurrence in stage II colon cancer patients

I. Archilla^*, E. Hernandez-Illan, E. Asensio, Q. Ferrer, S. Lahoz, C. Montironi, A. Castells, M. Cuatrecasas, J. Camps

^*Hospital Clinic, UBarcelona, Pathology, Spain

Background & Objective: Stage II colon cancer (CC) holds a major therapeutic challenge since adjuvant chemotherapy is not systematically indicated. However, up to 15% of stage II CC patients show recurrence within 5 years after surgery. This is partially due to the fact that lymph node staging is not sensitive enough and the lack of molecular biomarkers able to predict relapse. We aimed to identify genomic imbalances associated with the increased risk of recurrence in stage II CC.

Method: Here we analyzed 84 stage II (pT3-T4, N0) CC using SNP-arrays and fluorescence in situ hybridization (FISH) to identify copy number alterations (CNAs). We also collected pathological risk factors data, microsatellite instability status, CDX2 expression, tumour infiltrating lymphocytes and microenvironment components.

Results: Our data showed that tumours of patients with recurrence have a greater amount of CNAs. Moreover, our results suggest several candidate genomic regions to discern patients at risk of recurrence, such as the loss of 6q22.31 and 17q24, the gain of 13q, and copy-neutral LOH at 17p13. The single-cell based analysis of FISH signals showed increased levels of intratumour heterogeneity in primary tumours with higher rates of chromosome instability (P<0.0002). Additionally, patients with relapse showed higher number of subclonal cell populations involving chromosome13 gains than those without recurrence (median of 4.56 vs 3.88).

Conclusion: Intratumour heterogeneity mediated by the increased levels of genomic instability and acquisition of genomic imbalances might be associated with the risk of recurrence in stage II CC.

OFP-04-011

Tumour budding in gastric carcinomas: a promising indicator of prognosis

G. Özgün^*, E. S. Ayva, H. O. Aydin, B. H. Özdemir

^*Baskent University, Pathology, Ankara, Turkey

Background & Objective: Tumour budding frequently observed in carcinomas of the gastrointestinal tract. The aim of this study to investigate tumour budding in gastric carcinomas.

Method: Study compromised 95 patients with the diagnosis of gastric cancer between 2011-2018. All patients who underwent curative total or subtotal gastric resection with regional lymph node dissection. Data collected for analysis including age and gender of the patients, resection type, localization, size, histologic differentiation, and presence of lymphovascular invasion, perineural invasion, tumour budding, and lymph node status. The mean follow-up of the patients was 21,6±20,6 months.

Results: The mean age of the patients was 64,3±11,6 (range, 35-86 years), while the male to female ratio was 59/36. The mean size of the tumours was 5,8±3,5 cm (range 0,5-19 cm). Among 95 patients, 59 had adenocarcinomas, 31 had poorly cohesive carcinomas, and 5 had mucinous adenocarcinomas. Tumour budding found correlated with the tumour type, perineural invasion, peritumoural desmoplasia and patient survival in this study. We found a relationship between increased peritumoural desmoplasia and tumour budding. Lymphovascular invasion, as an independent prognostic parameter, found to be related to patient survival (p=0.01). In this study group, we didn't find a relation between the lymph node metastasis and tumour budding. Although tumour budding was found lesser in poorly cohesive carcinomas than adenocarcinomas (p<0.05), tumour budding reduced the overall 1-year and 3-year survival rates of poorly cohesive carcinomas from 40% to 22% and, 9% to 0% (p=0.03).

Conclusion: Tumour budding may be used as a parameter of tumour aggressiveness and as an indicator of unfavorable outcome.

OFP-04-012

Traditional serrated adenomas do not always prefer the colorectum

M. T. Aydugan^*, D. Akbulut Ipek, C. Cansiz Ersöz, S. Kiremitci, B. Savas, A. Ensari

^*Ankara University, Pathology, Turkey

Background & Objective: Traditional serrated adenomas (TSAs) outside the colorectum are quite rare and are believed to be aggressive lesions requiring total excision of the polyp to rule out the possibility of dysplasia or invasive neoplasia. In this study, we aimed to identify the immunophenotipic characteristics of upper GI TSAs and relate them to the serrated neoplastic sequence.

Method: A total of 12 TSAs located outside the colorectum were recruited and analyzed using an immunohistochemical panel including CK7,CK20, CDX2, B-Catenin, MUC2, MUC6, MUC5AC, P53, Ki67, MLH1, MSH2, MSH6, PMS2. Differential expressions of the antibodies were correlated with the characteristic and neoplastic features of this entity.

Results: Of 12 TSAs, 7 were located in the small intestine where two had invasive carcinoma, two showed low or high grade dysplasia while 5 were gastric TSAs among which one had invasive, two had intramucosal carcinoma and one had low grade dysplasia. Dysplastic and/ or neoplastic areas showed diffuse positivity with Ki67 and p53 and showed membranous Beta-catenin staining. Gastric differentiation was observed focally in 10 polyps with MUC5AC and MUC6 expressions whereas, 9 polyps showed focal MUC2 positivity. While all showed diffuse positivity with CK20 and CDX2, only 9 had focal CK7 positivity. Two (one gastric, one small intestine) TSAs were MSI.

Conclusion: Pathologists should be aware of unusual localization of TSAs and evaluate such cases with great care using immunohistochemistry in order to identify the aggressive potential of these polyps which is highly likely.

OFP-04-013

Radial asymmetry of histologic reflux findings at the gastro-oesophageal junction: greater sensitivity and better clinical correlation at the lesser curvature

D. Gomes Pinto^*, W. Plieschnegger, N. Schneider, M. Geppert, H. Bordel, G. Höss, A. Eherer, E.-M. Wolf, M. Vieth, C. Langner

^*Centro Hospitalar de Lisboa Ocidental, EPE, Anatomic Pathology Dept., Lisbon, Portugal

Background & Objective: The significance of histologic diagnosis of gastro-oesophageal reflux disease (GORD) is controversial. In the prospective Central European multicentre histoGERD trial, we investigated whether conflicting data in the literature are related to the site of biopsy sampling.

Method: Seven hundred and seventy-six individuals (410 females and 366 males, median age 54 years) participated in the study. Biopsy material was systematically sampled from above and below the gastro-oesophageal junction and analysed separately for the lesser and greater curvatures. Acute reflux-associated changes of the oesophageal squamous epithelium were assessed according to the Esohisto consensus guidelines.

Results: At the lesser curvature, 175 (22.6%) individuals had severe reflux-associated changes, compared with 115 (14.8%) at the greater curvature (p=0.0002). In all, biopsies from the lesser curvature had a higher sensitivity (84.6% vs. 72.7%) and specificity (93.2% vs 91.6%) for the detection of microscopic oesophagitis. Cardiac mucosa (54.8% vs. 47.6%, p=0.0052) and intestinal metaplasia (13.9% [sensitivity 81.2%] vs. 7.1% [sensitivity 41.2%], p <0.0001) were also more frequently observed at the lesser curvature, and biopsies obtained from this site showed a better correlation with patients’ symptoms and the endoscopic diagnosis of oesophagitis.

Conclusion: Histologic findings of GORD are not uniformly distributed at the gastro-oesophageal junction. Biopsies taken at the lesser curvature show a higher sensitivity for the diagnosis of microscopic oesophagitis. This applies to both (acute) inflammation-related changes of the squamous epithelium and their (chronic) consequences, such as cardiac and intestinal metaplasia.

OFP-04-014

Involvement patterns in inflammatory bowel disease: differences between initial and follow-up biopsies

D. Akbulut Ipek^*, F. G. Salman, S. Kiremitci, B. Savas, H. Cetinkaya, A. Ensari

^*Ankara University, Dept. of Pathology, Turkey

Background & Objective: The diagnosis of inflammatory bowel disease (IBD) requires multiple site colon biopsies including terminal ileum (TI). Therapy might have an effect in the involvement pattern of these sites by the disease. We examined the initial and follow-up biopsies of IBD patients in order to determine the involvement patterns in Crohn’s disease (CD) and Ulcerative colitis (UC).

Method: A total of 268 IBD patients with multiple biopsies obtained from TI and five colonic segments were evaluated for activity (cryptitis, crypt abscesses, ulceration) and chronicity (crypt distortion, mucin depletion, pyloric/paneth cell metaplasia) in all localizations. Comparisons were committed using Chi-square test.

Results: There were 167 UC (62.3%), and 101 CD (37.7%) patients with a male predominance in the UC group (59.9% vs. 43.6%, p<0.01). Among the cases with follow-up biopsies (68.3%) the majority were UC (73.1% vs 60.4%, p<0.05). TI and right colon involvements were more frequent in CD both in initial and follow-up biopsies (85% and 73.8% for TI, p<0.01; 37.5% and 37.7% for right colon, respectively, p<0.05). Pancolitis was higher in UC in both biopsies (60% and 33.6%, p<0.01) than CD. No difference was observed in CD between the initial and follow-up biopsies in contrast to UC which showed more left colon involvement in follow-up biopsies (62.3%, p<0.01). In UC, disease activity was correlated in TI and right colon (p<0.05, Phi=0.174).

Conclusion: Follow-up biopsies of pancolitic UC presented with either right or more commonly left colon involvement reflecting the effect of medical treatment while no such difference was observed in CD.

OFP-04-015

Pathogenesis of fibrosis in Crohn’s disease

M. Jerala^*, N. Zidar

^*Faculty of Medicine, Institute of Pathology, Ljubljana, Slovenia

Background & Objective: Fibrosis is an important complication of Crohn’s disease (CD). It is believed to result from tissue damage due to chronic inflammation and impaired wound healing and is characterised by proliferation of myofibroblasts and excessive deposition of extracellular matrix proteins. Despite significant morbidity, pathogenesis of fibrosis including origin of myofibroblasts is poorly understood.

Method: We analyzed resection specimens from 30 patients with CD. Normal mucosa from resection specimens of colorectal carcinoma was used for comparison. Samples were stained with Trichrome Masson and immunohistochemically for smooth muscle actin (SMA), CD34 and stem cell markers ALDH1, CD44, Oct4 and SOX2.

Results: In normal colon, we found numerous CD34+ ALDH1+ CD44+ spindle cells in the submucosa and subserosa, particularly around blood vessels. In CD, fibrosis highlighted by Trichrome Masson was found in the submucosa and subserosa, together with proliferation of SMA+ myofibroblasts and disappearance of perivascular spindle cells.

Conclusion: 1. Hot spots for fibrosis in CD are submucosa and subserosa. 2. Fibrosis in CD is characterised by proliferation of myofibroblasts and disappearance of perivascular spindle cells (pericytes/fibroblasts). 3. Distribution of pericytes/fibroblasts in the normal bowel wall, and their disappearance in fibrosis, in parallel with the appearance of myofibroblasts suggest that pericytes/fibroblasts are the source of myofibroblasts in CD. 4. These cells expressed stem cell markers, further supporting their postulated role as origin of myofibroblasts. 5. Pathogenesis of fibrosis in CD is thus comparable to fibrosis/scar formation in other organs, in which perivascular cells (fibroblasts/pericytes) have emerged as origin of myofibroblasts.

Monday, 10 September 2018, 08:30 - 12:00, Room A2

OFP-05 | Joint Session: Pulmonary Pathology / Nephropathology

OFP-05-001

Light chain proximal tubulopathy in the spectrum of B-cell dyscrasia induced renal disease

M. Büttner-Herold^*, T. Chuva, K. Minuth, F. Pfister, C. Daniel, M. Klewer, A. Buttner, F. Ferrazzi, S. Bertz, K. Amann

^*Institute of Pathology, Nephropathology, Erlangen, Germany

Background & Objective: B-cell dyscrasia can cause a multitude of renal pathologies even when sometimes diagnostic criteria for multiple myeloma (MM) or B-cell Non-Hodgkin lymphoma (BNHL) are not fulfilled. Therefore, the term of “monoclonal gammopathy of renal significance (MGRS)” was coined. The aim of this study was to assess the role of light-chain proximal tubulopathy (LCPT) in the context of LC-induced renal diseases.

Method: A consecutive cohort of 320 renal specimens was collected including cases with a history of MM, BNHL, MG or monoclonal immunoglobulin (Ig)/LC induced nephropathy. Special attention was paid to immunohistochemical LC restriction in proximal tubules and/or intracytoplasmic crystals as hallmarks of LCPT.

Results: LCPT was a frequent finding observed in about a quarter of analyzed specimens. In nearly three quarters it was associated with another LC-induced disease, especially LC-Cast-nephropathy (Cast-NP). A subgroup of LCPT (11.4%) was not associated with significant acute tubular injury (ATI) and showed better renal function than the remaining LCPT cases. After exclusion of cases with concurrent Cast-NP, LCPT was not associated with inferior renal function at diagnosis compared to non-LCPT cases.

Conclusion: In summary, LCPT is frequent in the context of renal disease in B-cell dyscrasia and associates with Cast-NP. This might indicate that it is in many instances a consequence of a high monoclonal plasmacell burden as usually found in Cast-NP. Together with the fact that a subgroup of LCPT is not associated with significant ATI these findings imply that in part LCPT is a tubular trafficking-phenomenon rather than an independent disease entity.

OFP-05-002

An integrative approach for the assessment of peritubular capillaritis extent and score in microvascular inflammation – association with transplant glomerulopathy and graft loss

N. Kozakowski^*, H. Herkner, F. Eskandary, M. Eder, W. Winnicki, G. Bond, Ž. Kikic

^*Medical University of Vienna, Dept. of Pathology, Austria

Background & Objective: In active antibody-mediated kidney allograft rejection (ABMR) the microvascular inflammation score (MVI), a positive C4d staining or gene transcripts of endothelial damage are currently seen as surrogates of HLA antibody-antigen interaction as they are strong predictors of TX-glomerulopathy (TG) and TX-loss. We recently observed the association of diffuse extent of peritubular capillaritis (ptc - inflammation in >50% of cortical peritubular capillaries) with increased risk of TX-loss and higher DSA-values. We tested the suitability of this pattern as additional surrogate of ongoing HLA-antibody interaction.

Method: We retrospectively reevaluated 616 patients for ptc morphology, TG in all biopsies (n= 1619) and death-censored TX-loss. We assessed more precisely our cases with a Ptc score=1, diffuse ptc extent and no glomerulitis (ptc1diffuse, n=26), currently not diagnostic for ABMR.

Results: Positive C4d and MVI-scores≥2 were found in 11 and 19% of the samples, TG in 13% of the patients. Including ptc1diffuse in the group of MVI≥2 significantly increased the AUC for TG (0.602, p=0.008) compared to the current MVI≥2 (0.560, p=0.12). After adjustment for confounders (C4d or cellular rejection), ptc1diffuse remained independently associated with TG [OR 3.89, p=0.008]. Patients with ptc1diffuse had significantly worse TX-survival than patients with MVI≥2 and <2 (42 vs.59 vs.70%, p=0.002).

Conclusion: Our integrated approach for ptc morphology, including the distribution of ptc (diffuse ptc) in the assessment of MVI, was better than current recommendations for the prediction of TG and subsequent TX-loss risk. It highlights a risk population currently not identified as such.

OFP-05-003

Molecular assessment of C4d positive renal transplant biopsies without evidence of rejection

C. Roufosse^*, M. Willicombe, T. Al Johani, J. Galliford, A. McLean, H. T. Cook, K. Dominy

^*Imperial College, Division Immunology, London, United Kingdom

Background & Objective: Immunohistochemical staining for C4d in peritubular capillaries is part of the definition of antibody-mediated rejection (AbMR) in the Banff Classification for Allograft Pathology. However, the clinical significance of C4d-positive biopsies without other evidence of rejection (C4d+ WER) is unknown. Our aim was to investigate the molecular significance of C4d positivity in such biopsies.

Method: RNA was extracted from formalin-fixed paraffin-embedded renal transplant biopsies (n=157) and gene expression analysis of 35 AbMR-associated transcripts was carried out using the NanoString nCounter system.

Results: AbMR-associated transcripts were significantly increased in samples with AbMR or suspicious for AbMR. A subgroup of 17/35 transcripts that best distinguished AbMR from C4d negative biopsies without evidence of rejection (C4d-WER) was used to study C4d+ WER samples. Most of the C4d+WER biopsies clustered with non-rejection biopsies in a heat map with hierarchical clustering. The 17 transcripts showed no differential expression between C4d- and C4d+ WER biopsies from both ABO incompatible and ABO compatible transplants. The geometric mean of the 17 transcripts was used to assign the C4d+WER patients a high- or low-risk score for AbMR. Follow-up biopsies showed AbMR within 1 year of the initial biopsy in 5/7 high-risk patients but only 2/46 low-risk patients. Logistic regression identified transcript risk group as a predictor of future AbMR, whereas factors including C4d score, DSA status, ABO status, number of transplants and time post transplant of biopsy were not.

Conclusion: Gene expression analysis in samples showing C4d positivity without evidence of rejection has the potential to identify patients at risk of imminent AbMR.

OFP-05-004

Thrombotic microangiopathy (TMA) in a cross-sectional study of native and transplanted kidneys: morphological, immunohistochemical and ultrastructural characterisation

J. Schmitz^*, W. Dai, A. Tölke, A. Khalifa, J. Menne, H. Haller, H. H. Kreipe, J. H. Bräsen

^*Institute for Pathology, Nephropathology Unit, Hannover, Germany

Background & Objective: Thrombotic microangiopathy (TMA) is a rare severe pathology defined as microvascular endothelial injury, thrombosis, thrombocytopenia and MAHA, often affecting the kidneys. Since TMA may manifest without thrombi, diagnosing TMA in kidney biopsies is demanding.

Method: Accepted morphological criteria were analyzed in archival routine paraffin sections of 225 TMA cases.

Results: TMA patients’ (female 45%) age ranged from 4 to 81 years. 45% of TMA cases occured in kidney transplants (KTx), 53% of these had rejection (cellular 7%, humoral 34%, mixed 12%). Thrombi were identified in 71% of KTx TMA cases (glomerular 41%, arteriolar 40%, arteries 25%) compared to 67% of native kidneys (glomerular 38%, arteriolar 53%, arteries 41%). Most useful histological TMA criteria were fragmented red blood cells (glomerular 65%, arterioles/arteries 67%), fibrillar appearance of mesangium (66%), endothelial swelling (glomeruli 68%, arterioles 67%), thickened capillary walls (66%), collapse of capillary tuft (92%) and arterial intimal mucoid edema (arteries 78%, arterioles 47%). Detailed ultrastructural comparison between TMA combined with humoral rejection and humoral rejection alone could not define any differences between these two groups. Grouping of clinically well-characterized patients regarding the underlying cause for TMA showed differences between morphological criteria comparing genetically verified atypical HUS (e.g. arteriolar/hilar involvement), humoral transplant rejection and toxic injury (e.g. gemcitabine revealed more glomerular and overall thrombi). Stains for thrombomodulin, heparanase-2, CD34, and glycocalyx did not seem to mirror these morphological differences hitherto.

Conclusion: Certain morphological criteria vary in their diagnostic value and show differences between causes of TMA. Morphologically and ultrastructurally, humoral rejection shares numerous similarities with TMA.

OFP-05-005

Precisely quantified B-cell infiltration in whole slide images (WSI) correlates with borderline, cellular and combined rejection in a cross-sectional study of transplanted kidneys

J. Schmitz^*, J. Johnsdorf, A. Khalifa, H. H. Kreipe, M. Schiffer, W. Gwinner, J. H. Bräsen

^*Institute for Pathology, Nephropathology Unit, Hannover, Germany

Background & Objective: Digital morphological approaches may facilitate the characterization of immune cell-mediated renal tissue injury in transplanted kidneys as precise quantification and localization of immune cells by eye is challenging.

Method: A total of 766 renal allograft biopsies, including both biopsies for clinical cause (57.8%) and biopsies from the Hannover Protocol Biopsy Program, were stained in an automated manner (Ventana) for B-cells using a monoclonal CD20 antibody, scanned (Leica), and subsequently analyzed for immunopositively stained area (%/region of interest) using a pixel-based digital approach (Definiens Tissue Studio). Results were evaluated separately for cortex, medulla, and extrarenal tissue.

Results: B-cell abundances in the biopsies (40.8% from females; age ranging from 2-78 years) differed significantly between patients with vs. without rejection (according to Banff criteria) and showed highest means (p≤0.05) in cellular rejection (no rejection: cortex 0.33%, medulla 0.14% ; borderline: cortex 0.65%, medulla 0.12%; cellular rejection: cortex 1.26%, medulla 0.35%; humoral rejection: cortex 0.33%, medulla 0.14%; combined rejection: cortex 0.67%, medulla 0.10%). Positive correlations (p≤0.05) for cortical B-cell densities were also obtained for fibrosis grades according to Banff category 5 and Banff coding for i, t, ti, v, ptc, ci and ct.

Conclusion: Cortical and medullary B-cell densities rather display high values in cellular (including borderline and combined rejection) than in humoral rejection. Associations with clinical data and long-term allograft outcome are currently under investigation.

OFP-05-006

Kidney biopsy codes for pathologists: towards a generally applicable terminology and coding system

A. Dendooven^*, H. Peetermans, M. Helbert, T. Wiech, H. Hopfer, K. Amann, S. Leh

^*UZ Antwerpen, Pathology, Belgium

Background & Objective: Kidney biopsy registries benefit research, teaching and policy-making using larger biopsy series. However, these registries are mainly using locally developed classifications with corresponding codes for registration of pathology diagnoses, and classification rules are not always provided. As classes often have not been mapped to an underlying terminology system, the different systems hamper or even prohibit comparison, exchange or accumulation of data. Consequently, there is a great need for a more standardized, universally applicable terminology and interoperable coding. Therefore we started the project “Kidney Biopsy Codes (KBC)”, aiming to provide a complete and structured set of terms and codes applicable to every non-neoplastic kidney biopsy by any nephropathologist, nephropathology unit or kidney biopsy registry.

Method: The project will be carried out in 5 work packages (WP), from April 2018 to mid 2019. WP1 investigates the current status of existing registries, current coding of renal biopsy diagnoses as well as analysis of strengths and weaknesses in international coding systems. WP2 designs principles for the new KBC system. WP3 addresses the technical design and generates the KBC as such. WP4 addresses review and improvement of the KBC by stakeholders. WP5 establishes structures crucial for maintenance and further development of the KBC. Cooperation with existing systems and organizations will be actively pursued.

Results: Results will be published in the scientific literature.

Conclusion: The KBC project has recently started, aiming to provide a comprehensive, generally applicable, interoperable and easy-to-update coding structure for recording of kidney biopsy diagnoses by pathologists.

OFP-05-007

The more the micropapillary pattern in stage I lung adenocarcinoma, the worse the prognosis - a retrospective study on digitalised slides

T. Zombori^*, T. Nyári, L. Tiszlavicz, R. Pálföldi, E. Csada, T. Géczi, A. Ottlakán, B. Pécsy, G. Cserni, J. Furák

^*University of Szeged, Pathology, Hungary

Background & Objective: Although the majority of lung adenocarcinomas show mixed pattern, only the predominant component is taken into account according to the novel classification. We evaluated the proportion of different patterns and their impact on overall survival (OS) and disease-free survival (DFS).

Method: Patterns were recorded according to predominance and their proportions were rated and calculated by objective area measuring on digitalized, annotated slides of resected stage I lung adenocarcinomas. Spearman-rank correlation, Kaplan-Meier models and the log rank test were used for statistical evaluation.

Results: 243 stage I adenocarcinoma were included. Lepidic pattern is more frequent in tumours without recurrence (20% vs. 8%), and lepidic predominant tumours have favourable prognosis (OS: 90.5%, DFS: 89.4%), but proportions above 25% are not associated with improving outcome. Solid and micropapillary patterns are more frequent in patients with recurrence (48% vs. 5% and 13% vs. 4%) and predominance of each one is associated with unfavourable prognosis (OS: 64.1%, DFS: 56.3% and OS: 28.1%, DFS: 28.1%, respectively). Above 25%, a growing proportion of solid or micropapillary pattern is not associated with worsening prognosis. In contrast, tumours having micropapillary pattern as secondly predominant, form a different intermediate group (OS: 51.1%, DFS 57.8%).

Conclusion: Our study was based on measured area of each growth pattern on all available slides digitalized. This is the most precise way of determining the size of each component from the material available. We propose using predominant and secondly predominant patterns for prognostic purposes, particularly in tumours having solid or micropapillary patterns.

OFP-05-008

Genetic MET alterations in non-small cell lung cancer: biologic differences and analogies

R. Castiglione^*, C. Alidousty, S. Wagener, B. Holz, A. Kron, J. Wolf, S. Merkelbach-Bruse, C. Reinhardt, R. Büttner, A. M. Schultheis

^*Institute of Pathology, University Hospital Cologne, Germany

Background & Objective: Non-small cell lung cancer (NSCLC) is one of the most common cancers and a leading cause of cancer-related deaths. The characterization of its genetic alterations, including MET aberrations, has drastically changed treatment options and overall survival. Aim of the study was to assess biological differences in the genomic background between MET amplifications and mutations.

Method: A subset of treatment-naïve NSCLC cases with either a MET high-level amplification (n=17) or MET exon 14 skipping mutation (n=17) was analyzed using next generation sequencing, gene amplification/translocation FISH-analysis, copy number variation analysis and MET-protein expression analysis.

Results: The MET-mutant cohort was represented predominantly by never-smokers, older female patients (p<0,001) showing recurrent MDM2 (n=6), CDK4 (n=3) and HMGA2 (n=3) amplifications. No other driver mutations were detected. Conversely, the MET-amplified group, represented smoker, younger male patients, harbored pathogenic KRAS mutations (n=3) and a higher frequency of TP53 mutations (p=0,016). Interestingly MET amplifications occurred more frequently as subclonal event, whereas MET mutations were present at high allele frequencies. High copy number variation burden was reported in both groups. MET-immunohistochemistry was demonstrated to be a reliable screening method for amplifications, but not suitable for mutations.

Conclusion: MET-mutant and MET-amplified cases differ significantly: the MET-mutant cohort harbored no co-occurring driver mutations, supporting the hypothesis that MET mutations may represent a strong oncogenic driver. Conversely, MET amplifications seem to occur primarily subclonally, in the background of other genetic driver events. Therefore, MET amplifications should always be interpreted in the context of the genetic tumour background, in particular when considering MET inhibition treatment options.

OFP-05-009

The expression and prognostic value of somatostatin receptor 1-5 in pulmonary carcinoid tumours

T. Vesterinen^*, H. Leijon, H. Mustonen, K. Salmenkivi, P. Vainio, C. Haglund, J. Arola

^*HUSLAB, Dept. of Pathology, Helsinki, Finland

Background & Objective: Pulmonary carcinoids (PC) belong to neuroendocrine tumours that often overexpress somatostatin receptors (SSTR). This overexpression provides a molecular basis for tumour imaging and therapeutic interventions with somatostatin analogs (SSA). The aim of this study was to evaluate SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5 distribution in a large set of PCs as well as to investigate if the expression associates with clinicopathological parameters and patient outcome.

Method: Histological samples (n=164) from consecutive PC patients treated surgically between 1990 and 2013 were retrieved through the Helsinki Biobank and the Auria Biobank. Clinical records were retrospectively reviewed. Tissue specimens were re-evaluated according to the World Health Organization 2015 classification, processed into tissue microarray format and stained immunohistochemically with Ki-67 and SSTR1-5.

Results: Based on re-evaluation, 77% (n=126) of the tumours were typical carcinoids (TC) and 23% (n=38) atypical carcinoids (AC). Expression of SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5 was detected in 52%, 86%, 55%, 15%, and 32% of the tumours, respectively. All SSTRs expressed membranous staining. SSTR expression was associated with tumour proliferation, metastatic potential, and patient outcome.

Conclusion: We showed that PC tumours express SSTRs immunohistochemically which provides a rationale for the imaging and treatment of these tumours with somatostatin analogs. As SSTR expression associates with tumour proliferation, metastatic potential, and patient outcome, these receptors may offer also a possibility for individualized prognosis estimation.

OFP-05-010

Nuclear RAD51 protein is associated with tumour-infiltrating lymphocytes (TILs) and survival outcomes in non-small cell lung cancer patients, treated with neoadjuvant chemo-/radiotherapy

M. Gachechiladze^*, J. Skarda, V. Kolek, I. Grygarkova, K. Langova, P. Voita, J. Vbrkova, M. Hajduch, Z. Kolar, R. Stahel, W. Weder, U. Rulle, A. Soltermann, M. Joerger

^*Palacky University, Olomouc, Czech Republic

Background & Objective: The effect of DNA repair on the tumour microenvironment is not well studied. We aimed to analyse the relationship between the expression of nuclear RAD51 protein and tumour infiltrating lymphocytes (TILs) chemotherapy-naive versus chemotherapy-pretreated patients non –small cell lung cancer (NSCLC).

Method: The training set included 96 patients from the University Hospital Olomouc, Czech Republic, from which 20 patients were treated with platinum-based neoadjuvant chemotherapy. The validation set included 1109 patients from the University Hospital, Zurich, Switzerland, from which 126 were treated with neoadjuvant platinum-based chemotherapy and/or radiotherapy. TMA sections from training and validation sets were staind with antibodies against RAD51, CD8, CD68 and PD-L1. TILs were assesed in matched H&E slides.

Results: The loss of nuclear RAD51 protein was associated with increased number of TILs in patients treated with neoadjuvant chemo-/radiotherapy in both training (r=-0.388, p=0.001) and validation (r=-0.292, p=0.011) sets. In addition, nuclear RAD51 positivity (Hscore>0.2) and decreased numbers of TILs (dichotomised for median) was associated with poor overall and disease-free survivals (p<0.05)

Conclusion: The present results suggest low RAD51 expression to be a surrogate marker for a high tumour mutational burden in patients with NSCLC receiving neoadjuvant treatment. RAD51 expression should further be assessed as a potential biomarker for the treatment with PD-(L)1 targeting monocloncal antibodies.

OFP-05-011

Spread through air spaces (STAS) is a predictor of poor outcome in pulmonary carcinoids

J. Metovic^*, S. Altinay, F. Massa, G. Gatti, M. Volante, M. Papotti

^*University of Torino, Dept. of Oncology, Italy

Background & Objective: Spread through air spaces (STAS) is a recently recognized prognostic factor for pulmonary adenocarcinomas and squamous cell carcinomas. Pulmonary neuroendocrine neoplasms (NEN) include lesions having variable morphology and a heterogeneous clinical behavior, with few factors predicting the outcome, therefore the aim was exploring the presence and potential prognostic role of STAS.

Method: A retrospective series of 260 surgically resected NENs, including 230 carcinoids and 30 control high-grade small and large-cell NE carcinomas, was reviewed. STAS was defined by the presence of neoplastic nests or single cells in air spaces beyond the tumour edge. In selected lung cancer cases, c-MET expression, an invasive growth and poor prognosis marker, was evaluated.

Results: Clinico-pathological parameters and survival were correlated by univariate and multivariate analyses. STAS was identified in 32.7% of NENs (85/260) and 26.9% of carcinoids (62/230). STAS increased with increase of tumour grade, occurring in 20.5% typical carcinoids, 42% atypical carcinoids, 71% large-cell and 88% small-cell carcinomas. STAS presence in carcinoids was significantly correlated with patients’ sex, age, angioinvasion and nodal status. STAS was associated to a shorter time to progression and overall survival in the whole series, and with survival within the atypical carcinoid subgroup. A stronger c-MET expression was observed in carcinoids rather than high-grade carcinomas, including reactivity in peripheral tumour cells and STAS.

Conclusion: In conclusion, STAS is of prognostic relevance also in pulmonary neuroendocrine neoplasms, being a significant predictor of poor survival in carcinoids, including the atypical forms, that currently have the most unpredictable outcome.

OFP-05-012

Transbronchial cryobiopsy: a single-center experience

G. Vlacic^*, I. Kern, A. Rozman

^*University Clinic Golnik, Pathology and Cytology, Slovenia

Background & Objective: Transbronchial cryobiopsy (TBC) is establishing itself as a diagnostic tool for diffuse parenchymal lung diseases (DPLD) with a higher diagnostic yield than a classic transbronchial biopsy (TBB) and fewer peri- and post procedural complications than an open surgical lung biopsy. Our goal was to present our experience with this procedure and demonstrate its value in the diagnostic workup of DPLDs.

Method: We analyzed 50 cryobiopsies performed between 2016 and 2018 at our clinic in the workup of 50 patients aged from 46 to 80 (mean 67 years) with a clinically suspicious DPLD. In 19 cases the clinical suspicion was hypersensitivity pneumonitis (HSP), in 8 lung involvement in connective tissue diseases (CTD), in 9 idiopathic pulmonary fibrosis (IPF), in the remaining 14 cases the working diagnoses were various. We compared the histological findings in TBBs with the histological findings after TBCs.

Results: 45 TBCs were diagnostic, 3 non-diagnostic and 2 suboptimal. UIP was the most common pattern, 14 cases, followed by 11 cases of NSIP, 9 HSP, 2 obliterative bronchiolitis, 2 bronchiolitis, 2 unclassified fibrosis, 1 NSIP with features suggesting a CTD, 1 PLCH and 1 peribronchiolar fibrosis. In 36 cases a TBBs was performed before TBC. In 33 cases the findings were non-diagnostic. In 3 cases a possible DPLDs was suggested.

Conclusion: TBCs have a higher diagnostic yield than TBBs for DPLDs. We would recommend this procedure as a replacement for TBBs for the diagnosis of DPLDs.

OFP-05-013

Impact of tumour budding, cell nest size and spread through airspaces in pulmonary squamous cell carcinoma

C. Neppl^*, I. Zlobec, M. Keller, R. Schmid, S. Berezowska

^*University of Bern, Insitute of Pathology, Switzerland

Background & Objective: Tumour budding is a well-established independent prognostic factor in various cancer types (e.g. colorectal). Recently, grading systems that utilize tumour budding and other morphological parameters have been proposed as prognostic factors in pulmonary squamous cell carcinoma (pSQCC).

Method: We analysed a cohort of 354 primarily resected pSQCCs (2000-2013) (UICC 2017 stage I n=108, II n=117, III n=119, IV n=10). The parameters cell nest size, tumour budding (≤4 tumour cells; assessment following the recommendations of the International Tumour Budding Consensus Conference (ITBCC)), spread through airspaces (STAS), and desmoplasia were evaluated. Morphological findings were correlated with clinical and survival data.

Results: Low tumour budding (0-4 buds) was observed in 41%, intermediate (5-9 buds) in 30%, and high (≥10 buds) in 29% of cases (mean bud count=9, max=102). Cell nests of <1, 1-4, 5-15, >15 cells were present in 68%, 20%, 5%, 7%, respectively. We detected STAS in 32% of cases, desmoplasia in 68%. Tumour budding strongly correlated with tumour size, T-/ N- and UICC stage, assessed using HE and Pancytokeratin stained slides, and in continuous as well as categorized values (p<0.005). Tumour budding was a significant prognostic parameter for overall, disease specific and progression free survival (all p<0.005). Cell nest size and STAS showed no prognostic value.

Conclusion: The histomorphological parameter tumour budding provides an accurate prognostic stratification in pSQCC. Application of the scoring system recommended by the ITBCC is suitable for the evaluation of tumour budding in pSQCC.

OFP-05-014

Testing of ROS1-positive tumours by IHC displays a FISH-positive subgroup which might not benefit form recently approved drug therapy

V. Ruesseler^*, C. Heydt, E. Binot, L. Bubendorf, R. Buettner

^*Institut for Pathology, University Hospital Cologne, Germany

Background & Objective: Non-small cell lung cancer (NSCLC), still having a high mortality rate, show in many cases define genetic alterations, whereas rearrangements of the ROS proto-oncogene 1 (ROS1) gene occur in 1-2 %. Crizotinib, an inhibitor of ROS1-kinase activity, has been recently approved by the FDA for advanced stages of ROS1-positive NSCLC. Current gold standard for detecting ROS1-gene-rearrangements is by fluorescence-in-situ-hybridization (FISH), either by presenting a break-apart-pattern or by displaying one or more isolated-green-signals. But the last mentioned subset of ROS1-positive-cases seems not to benefit from the therapy. Therefore we wanted to further characterize this subgroup.

Method: ROS1-positive formalin-fixed, paraffin embedded (FFPE) tumour-samples, 10 with the classic break-apart-pattern and 10 with isolated-green-signals, were reevaluated by FISH (ZytoLight ® SPEC ROS1 Dual Color Break Apart Probe, Zytovision) and analyzed regarding ROS1-protein expression by immunohistochemistry (IHC) (D4D6®,Cell Signaling).

Results: 100% of the cases with break-apart-pattern show a detectable protein expression (either weak, moderate or strong). But in 80% of the cases with isolated-green-signals no protein expression was detectable and only 20% presented a weak or moderate staining.

Conclusion: Our results indicate that ROS1-positive tumours presenting isolated-green-signals in FISH seldom seem be able to produce a stable protein expression detectable by IHC. This could be the reason why most patients of this subgroup does not benefit form a Crizotinib-therapy, as in most cases the drug target is simply not present. But further investigations need to be done to understand the biology of this subgroup.

OFP-05-015

Focal adhesion ILK-PINCH-PARVIN complex interacts with KRAS signaling in human lung adenocarcinoma

S. Nikou^*, M. Arbi, V. Zolota, H. Papadaki, G. T. Stathopoulos, V. Bravou

^*University of Patras, Dept. of Medicine, Patra, Greece

Background & Objective: The ternary complex of integrin-linked kinase (ILK), PINCH, and PARVIN (IPP complex) interacts with the cytoplasmic tail of beta integrins coupling cues from the extracellular matrix to the actin cytoskeleton. The IPP complex is known to be critically implicated in human cancer. Recent data from pancreatic cancer suggest a link between ILK and oncogenic KRAS. This study aimed to elucidate potential IPP-KRAS interaction in lung adenocarcinoma.

Method: IPP levels were evaluated by western blotting, qPCR and immunofluorescence (IF) in a panel of lung cancer cell lines with various KRAS levels (shKRAS, overexpressed KRAS) and mutational status (wt, mut) were evaluated. Levels of KRAS and downstream targets (pERK, pAKT) were also examined upon ILK inhibition. Effect of ILK targeting on cell proliferation of wtKRAS, mutKRAS and shKRAS lung cancer cell lines was examined by MTT assay. Expression of IPP complex was evaluated in human primary lung adenocarcinoma tissue samples and mouse lung tissue upon KRAS-driven lung carcinogenesis.

Results: IPP complex is downregulated in shKRAS lung cancer cell lines. ILK inhibition more effectively suppresses mutKRAS lung cancer cell proliferation. IPP components and EMT markers are overexpressed in human lung cancer tissue and their expression correlates significantly with aggressive clinicopathological parameters and poor prognostic outcome. IPP is also overexpressed in lung lesions from KRASG12D (lsl) mice examined.

Conclusion: These results suggest that there is a KRAS-IPP feedback loop in lung cancer enhancing oncogenic KRAS and IPP signaling with significant clinical relevance.

Monday, 10 September 2018, 08:30 - 12:00, Room B1

OFP-06 | Joint Session: IT in Pathology / Other Topics (Pathology in Favour of Developing Countries / Cardiovascular Pathology / History of Pathology / Autopsy Pathology)

OFP-06-001

Digitalisation of diagnostic histopathology slides: a comparative study and internal survey on perception toward the digital future

J. Unternaehrer^*, S. Reinhard, T. Waldburger, E. Hewer, I. Zlobec

^*University of Bern, Dept. of Pathology, Switzerland

Background & Objective: In this project, we performed a comparative analysis of four slide scanners with the aim of better identifying our institute’s needs. Second, we investigate our pathologists’ standpoint towards digital pathology.

Method: Two slide sets were used: 1) dayload approx. 1600 slides, 2) 34 slides including special stains, immunohistochemistry and cytological samples. Compared were file size, scan time, tissue recognition, image quality, re-scan rate, number of interruptions during batch scanning, and handling. A survey was sent to pathologists and residents encompassing questions about previous experiences, perceived advantages/disadvantages, machine-/deep-learning, attitude toward digital diagnostics.

Results: At 40x, the difference between smallest and largest file size was 4.5x. Major differences in scanning times were observed, reaching 1-minute difference between the longest and shortest. Only two scanners successfully scanned the full dayload without interruption. Re-scan rates were 9-19%, failure in tissue recognition ranged from 2.8-6.3%. Image quality and diagnostic confidence was considered high at 40x only. 75% of pathologists imagined working digitally but 50% anticipate problems with standardization. Image analysis is seen as an important benefit.

Conclusion: Each scanner has advantages and disadvantages and their proper fit into routine will be individual to an institute. In general, our pathologists are open to the digital future

OFP-06-002

Recognising molecular subtypes of colon cancer from virtual slides

V. Popovici^*, F. Bosman, E. Budinská

^*Masaryk University, RECETOX, Brno, Czech Republic

Background & Objective: Recent efforts in stratification of colon cancer (CC) patient population led to the identification of four consensus molecular subtypes (CMSs), representing the common denominator of several independently-developed molecular taxonomies. The current predictor of CMSs requires profiling hundreds of genes which clearly is not applicable in routine clinical practice. The goal of the current investigation was to establish image-based classifiers for CMSs that could operate independently and provide predictions for the most probable subtype.

Method: A set of n=200 virtual slides representing H&E sections of CC tumours and the accompanying whole-genome expression profiles were used for training CMS predictors. An independent set of n=100 virtual slides were used as validation set. For image feature extraction, we used deep convolutional neural networks trained on low magnification images (10x). A hierarchical decision system based on support vector machines with radial basis function kernels was trained and validated.

Results: The system identified a number of image features related to tumour architectural patterns that were preferentially enriched in one or several of the CMSs. The non-linear classifier built on these features achieved a good overall performance in predicting the CMSs (accuracy 0.85, 95% CI=(0.76, 0.91) on the validation set)

Conclusion: The virtual slides bear information that may be mined for building surrogate biomarkers for molecular subtypes of CC. Such system may operate autonomously and provide early indications of the most probable CMS.

OFP-06-003

A word mining approach to select immune-oncological biomarkers

S. Klein^*, A. Quaas, R. Büttner, K. Brinker

^*Institute for Pathology, Cologne, Germany

Background & Objective: The selection process of biomarkers is challenging in the era of high-throughput and multiplex techniques, because of the excessive amount of published data, and the given complexity of cancer in general - leading to either time consuming literature search, or a lack of representativeness of a given set of biomarkers. However, using automatic text mining techniques from the field of artificial intelligence, one may augment a preliminary set of biomarkers which are manually selected by medical experts. Together, we applied an evidence-based method to generate a marker set for immune-oncological purpose.

Method: First, a large-scale dataset of 50.000 abstracts of highly cited publications from the field of immune-oncology was generated using a set of topic related search terms. Second, a chain of text extraction processing, and filtering methods were used to automatically compute a relevance-sorted list of biomarkers from this dataset. To validate these markers, we sought to investigate the expression of these markers among three common cancer types, including lung adenocarcinoma, lung squamous cell carcinoma, as well as malignant melanoma from the TCGA database for correlation with mutational burden, and estimated immune cell infiltrates.

Results: The analysis revealed a set of about 250 markers of interest, that were ranked according to our approach, and correlated to immune-cell infiltration, as well as mutational burden in the common cancer types.

Conclusion: Together, these findings underscore that empirical word mining approaches can shed light on to biomarkers that have been described in function-/ and or biological relevance in the literature, but may have been neglected previously in the field of cancer research.

OFP-06-004

The results of the quantitative evaluation of Ki67 by the open and commercial software for automatic image analysis in invasive breast carcinomas

V. Kushnarev^*, A. Kudaibergenova, A. Artemyeva

^*Petrov Cancer Research Center, Pathology, Saint Petersburg, Russia

Background & Objective: Evaluation of the index of proliferative activity of Ki67 (LI Ki67) is variable between the researchers and is characterized by insufficient reproducibility. The method of digital image analysis makes it possible to improve the reproducibility and accuracy of the index estimation to create single recommendations. There are both commercial software products for image analysis, and freely distributed. For our research, we chose QuantCell software (module NQ) from 3D Histech and freeware QuPath software (module CD).

Method: We selected 100 cases of invasive breast carcinomas, G2-G3, which were retrospectively analyzed by an expert to assess the Ki67. Slides were scanned and the scans were analyzed in tumour zones with an area of ​​1 mm2.

Results: The CD and NQ modules did not differ significantly (p = 0.1). Analysis of the data of the CD module and the visual evaluation of the pathologist showed no difference (p = 0.5). We compared modules CD / NQ - ICC was 0.92 CI 95%, [0.86; 0.95] and CD / pathologist - 0.85 CI 95%, [0.73; 0.91]. Coefficient of correlation Spearman was 0.96, p <0.001 for CD / NQ, and 0.9, p <0.001 CD / pathologist.

Conclusion: The of LI Ki67 values ​​obtained by the CD module of freeware software showed a strong correlation with the commercial software of NQ module, as well as the pathologist. Free software QuPath can serve as a tool for increasing the reproducibility of the Ki67 proliferative activity index and compete with commercial software for image analysis.

OFP-06-005

Development and implementation of a novel affordable telepathology approach for developing countries

M. Botteghi^*, L. Istani, J. Bauer, M. Martinelli, V. Stracca Pansa, P. Giovenali

^*Università Pol. delle Marche, DISCLIMO, Dogana, San Marino

Background & Objective: Telepathology has been posited as a means of bolstering diagnosis delivery in developing nations. Digital divide and high costs for digital imaging technologies prevent the diffusion of telepathology in Low&Middle-Income Countries. A novel low-cost method for slides digitization and remote diagnosis-based con the innovative telemedicine platform WaidX has been implemented at Balbala Hospital, Djibouti, aimed to: enable real-time sharing of virtual slides to guide diagnostics decision making, conference calling for learning&training of local health workers, generation of a database for clinical data that serves as a departmental registry and as tool for future research use.

Method: The initiative was funded by APOF NGO. The telepathology system is comprised of a redundant WaidX physical core, one Olympus CX23 microscope equipped with a low-cost CCD camera, a HP PC equipped with Microvisioneer applications to support slides digitization and sharing. WaidX VoIP and Webex were used to establish the teleconference.

Results: The first telepathology interaction among Djibouti, Italy, San Marino and Germany occurred on March 26th, 2018. Demonstration of manual scanning revealed ease of use. Virtual slides were easily shared without compromise of the image resolution. Conference call quality was high. This conference has opened a series of remote training sessions devoted to immunohistochemistry, lead by APOF specialists.

Conclusion: Telepathology is feasible with excellent voice quality, slides sharing capability and real-time diagnostics. The database is under construction. We are developing a new affordable model for learning, training and collaboration in surgical pathology using WaidX, to enable rapid knowledge and technology transfer for a more equitable access to high-quality cancer care worldwide.

OFP-06-006

"Copper pennies in the tropics": chromoblastomycosis, a diagnosis not to be forgotten on tropical pathology

G. Medeiros^*, G. Morgantetti, M. Balancin, A. Fabro, V. Capelozzi

^*Laborocha Filho-SingularMD, Pathology, Fortaleza, Brazil

Background & Objective: Chromoblastomycosis, a deep mycotic infectious condition, resulted from traumatic injury and inoculation of dematiaceous fungi is a slow-course disease, predominantly reported in rural areas with tropical or subtropical climate, in some instances associated with malignancy. Its diagnosis is simple, direct and feasible once accounted.

Method: A 62-year-old male complained about a slowly-growing, firstly painless, thigh lesion. On presentation to the dermatology clinics, exhibited an extensive ulcerated and verrucous thigh lesion, on which an incisive biopsy was performed.

Results: Histopathologic examination of the biopsy revealed an extensive ulcerative process, with marked acanthosis, pseudoephiteliomatous hyperplasia and superficial granulomas, on which usual dark-coloured sclerotic bodies were evidenced without the need for further special stains. No significant atypia or other infectious agents were detected.

Conclusion: Chromoblastomycosis is a feasible and direct diagnosis when accounted as a differential, no special stain is needed for direct observation of its pathognomonic sclerotic (Medlar) bodies, reported in up to 92.5% of cases. A highly suspicious differential should warrant its diagnosis in a slow-course kin lesion, ulcerated, with acanthotic, granulomatous, multinucleated giant cell from a tropical or subtropical climate country-originated patient, as Central and South America (Brazil, Uruguay), India, Sri Lanka, Madagascar. Histopathological exam should be granted to all suspicious lesions, including during treatment, in order to exclude malignancy-associated disease (squamous cell carcinoma), as previously reported, allowing for specific treatment and follow-up on one of the most difficult deep fungal diseases to eradicate.

OFP-06-007

NK cells in endomyocardial biopsies from cardiac allografts: detection, quantification, and precise localisation using multiplex immunofluorescence

M. Terada^*, J. Calvani, M. Rabant, C. Lesaffre, J.-P. Duong Van Huyen, P. Bruneval

^*INSERM U970, Paris Transplant Group, France

Background & Objective: Among the complex cellular interplay engaged in cardiac rejection, recent transcriptomic analysis of endomyocardial biopsies (EMB) has detected NK cell transcripts in the setting of antibody-mediated rejection (AMR). The precise in situ detection of NK cells in EMB supporting this molecular signature remains to be done.

Method: FFPE sections from 51 EMB [10 without rejection (NOR), 21 with acute cellular rejection (ACR) and 20 with AMR] were analyzed with anti-NKp46 antibody by immunoperoxidase. To ascertain the precise intravascular or extravascular location of NK cells and their relationship with T lymphocytes and macrophages, multiplex immunofluorescence labeling kit Opal™ (PerkinElmer) was used with anti-NKp46, CD3, CD163 and CD34 antibodies for NK cells, T lymphocytes, macrophages and endothelial cells respectively. Computerized quantification and compartmentalization of all immune cells was performed with inForm® software (PerkinElmer).

Results: The density of NK cells was very low in NOR EMB (mean ± SEM: 0.44 ± 0.23/mm2) and significantly increased in AMR and ACR (12.32 ± 2.94 vs. 19.61 ± 6.77 respectively, p<0.0001). Both DAB and multiplex immunofluorescence labelings demonstrated a differential compartmentalization of NK cells in ACR vs. AMR: in ACR, most of NK cells were extravascular (p<0.05), whereas they were prominently intravascular in AMR (p<0.05). Multiplex immunofluorescence labeling showed that NK cells took part to graft inflammation during rejection together with T-lymphocytes and macrophages.

Conclusion: NK cells are recruited in both ACR and AMR. Their compartmentalization differs between ACR and AMR. NK cells colocalize with T lymphocytes and macrophages and appear as a cell type engaged in cardiac rejection.

OFP-06-008

Development of fibrosis in cardiac allografts: a comparative single-centre study of two consecutive decades

K. Wassilew^*, G. Petrov

^*Rigshospitalet, Dept. of Pathology, Copenhagen, Denmark

Background & Objective: The use of mechanical circulatory support as bridge-to-transplant is growing due to limited donor availability. It is uncertain whether development of cardiac fibrosis in heart transplant allografts is influenced by previous mechanical circulatory support. This is particularly important, because cardiac fibrosis is causative for progressive deterioration of cardiac function.

Method: We compared levels of fibrosis in consecutive right ventricular endomyocardial biopsies harvested over two calendar years separated by a decade from which fibrosis data were available (n= 101 in 2001 versus n= 248 in 2011). Gender, age of both recipient and donor at time of transplantation and time after transplantation were considered, before the patients were subdivided into distinct groups by use of mechanical circulatory support.

Results: Overall fibrosis levels differed only insignificantly (non-MCS group 9.2% vs 6.0% MCS group in 2001; non-MCS group 8.8% vs MCS group 5.9% in 2011). But significant differences in scar levels were found between decades, which were increasing in the MCS group (p<0.001, 14.9% in 2001 vs 18.4% in 2011 and decreasing in the non MCS-group 22% in 2001 vs 15.3% in 2011).

Conclusion: No relevant variation in fibrosis, but in scar levels in endomyocardial right ventricular biopsies in the two different consecutive decades could be demonstrated. Given similar donor age, difference in scar levels may be viewed as consequence of longer support times on MCS during the last decade and differences in underlying pathology of heart failure. Our findings merit further investigations.

OFP-06-009

Toll-like receptors 2 and 9 type in diagnostics of myocarditis

E. Kogan^*, O. Blagova, N. Fayzullina, A. Nedostup

^*Sechenov University, Anatomic Pathology, Moscow, Russia

Background & Objective: To study the expression of toll-like receptors (TLR) 2 and 9 in the myocardium and to evaluate their possible diagnostic and prognostic role in patients with chronic myocarditis.

Method: Myocardial samples were taken from 23 patients with different forms of non-coronary myocardial damage (myocardial right ventricular biopsy, n = 21; autopsy material, n = 2). According to the presence of myocarditis sampleas were divided into group I with dilation cardiomyopathy and myocarditis (10 patients) and group II without myocarditis (13 patients). Histological and immunohistochemical (IHC) study of the myocardium were performed (vimentin, desmin, c-kit, Ki-67 and TLR2 and TLR9). PCR of blood samples and myocardium was made to detect herpes viruses and parvovirus B19.

Results: Active borderline lymphocytic myocarditis was diagnosed in all patients in group I and in 6 patients in group II, the viral genes were detected in the myocardium in 15 patients, including 5 without morphological signs of myocarditis. We found significant correlation only in TLR2 and TLR9 expression and the presence of morphological signs of active myocarditis. With borderline myocarditis, expression of TLR2 and TLR9 was lower than without myocarditis, which may reflect death depletion of cardiomyocytes in the late stages of the disease. The relationship between the expression of desmin and the persistence of viruses, as well as c-kit with the degree of myocardial dysfunction and cardiosclerosis.

Conclusion: TLR2 and TLR9 expression in the myocardium may be used as IHC markers of active myocarditis. The expression of these markers may reflect genetic predisposition to the myocarditis development and may be used as a key to potential target of therapy.

OFP-06-010

Histological and paleogenetic analyses of two pre-Columbian mummies

R. Gaeta^*, G. Fornaciari, G. Valentina, M. Isolina, S.-R. Tasha, C. Raul

^*University of Pisa, Italy

Background & Objective: Several pre-Columbian mummies are preserved in the Museum of Anthropology of the University of Florence. These bodies were brought from South America to Italy in the second half of the 19th century. We studied the natural mummies of two adults dated back between 1410 and 1530.

Method: Complete autopsies, histological and genetic analyses were performed.

Results: Histopathological study on the tissue specimens of the lungs of the first mummy showed numerous alveoli, in large fibrous stroma, areas of pulmonary anthracosis and a massive presence of alveolar exudate compatible with the diagnosis of bronchopneumonia. The other corpse presented a marked megavisceral syndrome characterized by megacolon, megaoesophagus and cardiomegaly. Amastigotes of Trypanosoma cruzi were clearly detected in the myocardial fibers. DNA was extracted and the shotgun metagenomic sequencing showed bacterial and fungal taxa that may resemble both the thanatomicrobiome and extant human gut microbiomes. Bacterial groups present in the mummies included the Bacillales, Enterobacteriales and, especially, the Clostridiales; it is feasible to hypothesize that these individuals were exposed to these pathogens by the ingestion of contaminated food and water. Furthermore, we detected the presence of sequences of Trypanosoma cruzi, Leishmania donovani and antibiotic-resistance genes.

Conclusion: The presence of antibiotic-resistance genes clearly indicates that these genes pre-date therapeutic use of these compounds and that they are not necessarily associated to a selective pressure of antibiotics use. Studies on the ancient microbiome represent an opportunity to better understand microbe-host interactions, the membership and ecology of microbes, the evolution of commensal and pathogenic microorganisms and their impact in health and disease.

OFP-06-011

Photography in pathology: history of medicine, art and science

A. Nocito^*, G. Sanchez Granel, S. Marquez, D. Zicre, D. Vidonne, F. Calderone

^*School of Medicine Rosario, Dept. of Pathology, Argentina

Background & Objective: Photography in Pathology is an important instrument that has great value to represent macroscopic and histological findings and to write academic or scientific publications. We decided to rescue, inventory and reclassify an invaluable photo collection held in our pathology department.

Method: A review of a photographic collection that belongs to the beginning of the 20th century was carried out. It has approximately 10.900 glass negatives of different sizes (8000 of 9 x 12 cm and 2900 of 13cm x 18cm) (gelatin silver bromide), with their paper copy (silver gelatin), 3000 glass slides (lantern slides) (size: 9 x 12 cm) an epidiascope (slide projector) and an antique album with photographs

Results: Up to this moment 6188 glass negatives have been analyzed (5148 of 9 x 12 cm and 1040 of 9 x 12 cm) and then grouped in different categories. Among them it is possible to mention: dermatological, cardiovascular, gynaecological, urological disease, etc. This collection showed macroscopic, microscopic, radiographic and clinical images from multiple medical specialties. We found several examples of diseases, some of them scourges of the past and among others we can quote: Hansen disease, measles, bubonic plague, smallpox, tuberculosis, and antrax. We could not make any review of the lantern slides

Conclusion: We believe these findings have great historical value, allowing us to access images of diseases that belong to the end of the 19th century, some of which have been eradicated. We do not find registered publications that report the existence of an archive of medical images of such magnitude

OFP-06-012

No autopsy, no diagnosis

T. Hermida Romero^*, J. Pombo Otero, M. Alvarez Martinez, R. Alvarez Rodriguez, A. Teijo Quintans, N. Cohen Marcano, L. Lopez Solache, A. Alvarez Garcia, G. Bou Arevalo, A. Concha Lopez

^*Hospital U De La Coruña, Biology, Spain

Background & Objective: The complexity and risks of brain biopsy requires, in the majority of neoplastic cases, establish the possible infiltration of the Central Nervous System (CNS) through radiological studies. We present two autopsy studies with unexpected results.

Method: The first case corresponds to a woman diagnosed of lung adenocarcinoma in transbronchial biopsy and the second one to a man with a diagnosis of follicular lymphoma in a lymph node biopsy. In both cases , the radiological study of the CNS considered the neoplastic infiltration and were treated accordingly. At the time of death, protocolized autopsies were performed with CNS samples fixed in Fine-Fix . Tissue samples submited to the service of microbiology, where they were studied by technology of Real Time PCR looking for infectious agents.

Results: The histological findings showed inflammation and necrosis withouth evidence of tumour . Nocardia and toxoplasma DNA were detected respectively, the groccot stain evidenced nocardia structures in the first case.

Conclusion: The infections diseases can mimicking neoplastic processes with important clinical repercutions and their diagnosis is crucial for correct treatment of patients . Without autopsy , these infections would not have been diagnosed, which supposed clinical pathological discrepancies type II according to the Goldman scale, revaluing the autopsy as hospital quality control.

OFP-06-013

Cardiac metastases: two cases from the emergency clinic

A. Sapargaliyeva^*, G. Mambetova, M. Ivakin, V. Grinberg

^*Pathology Bureau, Almaty, Kazakhstan

Background & Objective: Metastases in the heart are not rare, however, their diagnosis is a serious issue, especially in the elderly, when heart failure is explained by age-related issues.

Method: In 2017, we diagnosed two cases of metastases in the heart.

Results: First case: a 79-years-old patient with cardiooesophageal cancer, died in the clinic with an increasing heart failure. An autopsy revealed a tumour in the lower third of the oesophagus, which spread to the cardiac compartment of the stomach, diaphragm, pericardium, epicardium, and myocardium of a right ventricle. Histologically, the tumour included glandular structures with foci of massive necrosis. Extensive intramural metastases were found in the myocardium. Second case: a 90-year old patient K. was admitted to the hospital in a severe condition. In the course of a clinical examination, a tumour was discovered in the parietal lobe on the right hemisphere (1.6x2.5 cm) and a pigmented lesion on the right foot of the patient (5x3 cm). The patient's condition has progressively worsened, and on the fourth day, the patient died of heart failure. The autopsy revealed, isolated cardiac metastasis in the right atrium and left ventricle. Moreover, there were multiple brain metastases (up to 1.5 cm) in both hemispheres. A histological examination allowed to diagnose melanoma and distant metastases in brain and heart.

Conclusion: Metastatic heart disease in both cases was diagnosed post-mortem as a result of the autopsy, while medical documents did not provide an explanation for progressing heart failure. The histological study allowed to reveal the tumour’s origin.

OFP-06-014

Clinico-pathological discrepancies in the diagnosis of causes of death in adults in Mozambique

N. Rakislova^*, P. Castillo, C. Carrilho, F. Fernandes, J. Ordi

^*Hospital Clínic, Pathology, Barcelona, Spain

Background & Objective: Autopsies have an important role in the quality control of clinical diagnoses and treatment. Clinical errors are likely to be more frequent in settings with limited available diagnostic techniques. In this study, we aimed to assess the accuracy of clinical diagnoses in a quaternary hospital in sub-Saharan Africa by comparing them with the postmortem findings, and to identify potential risk factors for misdiagnoses.

Method: Clinical records and autopsy findings from a series of 112 adults, excluding maternal deaths, occurring at the Maputo Central Hospital, Mozambique (n=112) during 2013-2015 period were reviewed. Discrepancies between clinical and autopsy diagnoses were evaluated using a modified version of Goldman and Battle classification and all major clinical errors were analyzed.

Results: A major diagnostic discrepancy was detected in 64(57%) cases. Major clinical errors were particularly frequent in deaths secondary to infectious diseases (55/80[69%] major discrepancies). Major clinico-pathological discrepancies were identified in 11/11(100%) infections caused by toxoplasma,9/11(82%) invasive fungal infections, 9/12(75%) sepsis,15/23(65%) tuberculosis,3/4(75%) meningitis, and 7/13(56%) pneumonias. The percentage of major discrepancies in HIV-positive patients(48/73, 66%) was higher than in HIV-negative patients(17/39,44%)(p=0.0282, Fisher’s exact test).

Conclusion: Major clinico-pathological discrepancies were frequent in this series of adults in sub-Saharan Africa. Increasing clinical awareness of the impact of infectious diseases and the introduction of a few, simple, diagnostic tests could significantly improve the recognition of common and life-threatening infections, and thus reduce the mortality associated with these diseases. The high frequency of clinico-pathological discrepancies questions the validity of mortality reports based on clinical data or verbal autopsies.

OFP-06-015

Epidemiological characteristics and anatopathological aspects of deaths caused by Chikungunya fever in a specific region

J. C. Melo^*, D. N. de Melo, D. N. Oliveira, K. W. Lopes Gomes, L. M. Franco, R. L. Sousa do Vale, G. B. da Silva Júnior

^*University of Fortaleza, Graduate Programme, Brazil

Background & Objective: The arboviruses are a global public health problem, causing epidemics with severe and atypical cases, with both joint and neurological impairments and deaths. In Fortaleza, Brazil, there is a co-circulation of Dengue (DENV) and Chikungunya (CHIKV) viruses, making the clinical management of such cases difficult, due to the similarity of signs and symptoms and to the limited laboratory support. Many deaths have post-mortem laboratory confirmation in obtained during necropsies performed by the Death Verification Service.

Method: We describe the clinical-epidemiological and anatomopathological characteristics of deaths by Chikungunya Fever in Fortaleza, Brazil, acquired from the Mortality Information System (MIS) and from the death records of the Country Health Department.

Results: 60,563 cases of Chikungunya Fever were reported, from these, 144 deaths were confirmed by the Arboviruses Mortality Investigation Committee; 22 necropsies of suspected deaths were held; two developed Guillain-Barre syndrome, three showed encephalitis; 19 with IgM reagent, two with positive immunohistochemical; three tested positive for DENV. Necropsies showed acute pulmonary edema (5/22), Lymphocytic encephalitis (2/22), lymphocytic myocarditis (2/22), steatosis and necrosis of hepatocytes (3/22).

Conclusion: Faced with the challenge to accurately report a death caused by Chikungunya, it becomes necessary to disclose the anatomopathological aspects found in necropsies, link them to the clinical findings as well as to alert the professionals about the risks and to create protocols that targeting reducing mortality.

Monday, 10 September 2018, 14:45 - 16:45, Room A2

OFP-07 | Joint Session: Soft Tissue and Bone Pathology / Infectious Diseases Pathology

OFP-07-001

A novel, low-grade paediatric soft tissue neoplasm defined by BRAF mutation

S. Smith^*, M. Mochel, J. Wojcik, M. Gowda, R. Patel

^*VCU School of Medicine, Pathology, Richmond, USA

Background & Objective: We describe two distinctive cases of a low-grade paediatric soft tissue neoplasm with clinical, immunophenotypic, and molecular features we believe are yet undescribed in the medical literature.

Method: We reviewed findings from clinical, radiologic, and histopathologic evaluations, as well as targeted ampliseq-based NGS of cancer-related genes.

Results: Two males, aged 11 months and 3 months, presented with plaque-like ulcerative soft tissue masses over the midline cervicothoracic and lumbar spines. Both masses infiltrated deeply, one involving the cervical and thoracic cord, extending into the retroperitoneum, the second into the lumbar epidural space. Histopathologic examination revealed both tumours to be centred in the deep dermis with extension through subcutaneous adipose to deep paraspinal soft tissues and into the epidural space. Neoplastic cells were small, monomorphous spindle cells with fibroblastic morphology and patchy lipomatous metaplasia, lacking cytologic atypia or mitotic activity. By immunohistochemistry, lesional cells were diffusely positivity for CD34 and negative for S100 and EMA. PDGFB rearrangements were absent by FISH. Sequencing revealed BRAF V600E mutations in both, one with a concomitant TP53 mutation, the other with APC mutation. Neither showed progression at 15 years or 6 months despite incomplete excisions.

Conclusion: These tumours express a distinct pathological and molecular profile with features raising a differential diagnosis of diffuse neurofibroma, lipofibromatosis, dermatofibrosarcoma protuberans, and tumours in the fibroblastic connective tissue nevus/fibrous hamartoma of infancy group. The BRAF mutations, combined with infiltration of deep axial and spinal cord structures and bland fibroblastic morphology are distinctive, though the congenital presentation and indolent course suggest a hamartomatous/connective tissue nevus-like lesion.

OFP-07-002

CD31 expression determines redox status and chemoresistance in human angiosarcomas

P. Ströbel^*, L. Trümper, G. Wulf, V. Venkataramani

^*University of Göttingen, Institute of Pathology, Germany

Background & Objective: Angiosarcomas (AS) are soft tissue sarcomas with endothelial differentiation and vasoformative capacity. Most AS show strong constitutive expression of the endothelial adhesion receptor CD31/PECAM-1 pointing to an important role of this molecule. However, the biological function of CD31 in AS is unknown.

Method: The expression levels of CD31 in AS cells and its effects on cell viability, colony formation and chemoresistance was evaluated in human AS clinical samples and in cell lines through isolation of CD31high and CD31low cell subsets. The redox-regulatory CD31 function linked to YAP signaling was determined using a CD31 blocking antibody and siRNA approach and was further validated in CD31-knockout endothelial cells.

Results: We found that most AS contain a small CD31low cell population. CD31low cells had lost part of their endothelial properties, were more tumourigenic and chemoresistant than CD31high cells due to more efficient reactive oxygen species (ROS) detoxification. Active downregulation of CD31 resulted in loss of endothelial tube formation, nuclear accumulation of YAP, and YAP-dependent induction of antioxidative enzymes. Addition of pazopanib, a known enhancer of proteasomal YAP degradation re-sensitized CD31low cells for doxorubicin resulting in growth suppression and induction of apoptosis.

Conclusion: Human AS contain a small aggressive CD31low population that have lost part of their endothelial differentiation programs and are more resistant against oxidative stress and DNA damage due to intensified YAP signaling. Our finding that the addition of YAP inhibitors can re-sensitize CD31low cells towards doxorubicin may aid in the rational development of novel combination therapies to treat AS.

OFP-07-003

Strategies of cytokines’ response under septic shock

N. Zotova^*, E. Gusev

^*IIP UB RAS, Immunology of Inflammation, Yekaterinburg, Russia

Background & Objective: We suppose that the mosaic releasing of inflammatory mediators, known as compartmentalization, is associated with prevalence of various stages of the cell stress in whole organism. These stages are: hyperergic (cell resistant to alteration, high level of cytokines' response) and depressive (cell tolerance, lower concentration of cytokines). The dominance of one of these stages is underlying the appropriate phase of systemic inflammation (SI). These stages are characterized by microcirculation disorders and organ dysfunctions, especially under septic shock.

Method: Rates of IL-6, IL-8, IL-10, TNFα, and CRP in the plasma were measured by the immunochemiluminometric closed system Immulite (Siemens Medical Solutions Diagnostics, USA). Groups of patients were the following: septic shock (SS) under acute sepsis (SS-AS) on the 1–2th days after admission at ICU, n=14, mean age – 54.9±16.4 years, lethality – 71.43%; SS under tertiary peritonitis, long and sub-acute sepsis (SS-SAS) (more, than 14 days after diagnosed), n=17, age – 50.2±5.6 yrs., lethality – 94.12%. Control group (donors), n=50, age – 34.1±10.4yrs.

Results: All of five studied indicators of SI in patients with SS were exceeding the control. Concentrations of cytokines in the blood of patients with SS-AS were significantly (P<0.05) increased as compared to the ones in SS-SAS. The levels of CRP in the groups were not significantly different.

Conclusion: Two variants of cytokines’ response in septic shock are associated with dominant stage of cell stress: hyperergic in SS-AS and depressive in SS-SAS.

OFP-07-004

Upstream regulation of Wnt pathway in bone and soft tissue tumours - diagnostic and therapeutic implications

V. Lee^*, S. K. Chua, E. Yeo

^*National University Singapore, Pathology, Singapore

Background & Objective: Aberrant Wnt signaling is found in both developmental diseases and cancer. Studies have shown that Wnt signaling plays a critical role in normal bone development. Aberrant signaling has been also implicated in the tumourigenesis of osteosarcoma and other sarcomas. We have developed a novel antibody, YJ5 against Wntless (WLS), a Wnt signaling pathway protein regulating Wnt secretion, which can be used to screen different tumours as potential candidates for treatment with an upstream Wnt (PORCN) inhibitor drug - ETC159. The objective of this study is to: 1) investigate if osteosarcoma (OS) and synovial sarcoma (SS) samples demonstrate aberrant Wnt signaling including elevated WLS levels 2) investigate if these tumours respond to treatment with ETC-159, a novel upstream Wnt inhibitor.

Method: YJ5 expression was analyzed in over 130 cases benign and malignant bone tumours and over 15 cases of synovial sarcoma. ETC159 was used to treat OS cell line (e.g. SJSA-1) (in-vivo) and two human SS cell lines (in-vitro). Response to treatment was analysed.

Results: 1) YJ5 was strongly expressed in synovial sarcoma, osteosarcoma, osteoblastic tumours and chondroblastoma. It was variably expressed in other tumours. 2) Treated OS samples demonstrated increased tumour necrosis (30-60 percent increase across all samples p<0.005). Treated SS samples show marked or significant inhibitory effect on downstream Wnt signalling proteins.

Conclusion: YJ5 antibody is a potential biomarker for identifying tumours with increased Wnt secretion that may be responsive to upstream Wnt inhibitors. ETC159 has a significant effect on tumour necrosis in osteosarcoma and inhibitory effect in synovial sarcoma.

OFP-07-005

Loss of RB gene (Monosomy 13) in the diagnosis of spindle cell lipoma, myofibroblastoma and cellular angiofibroma in unusual locations

R. Shi^*, A. Thomas, T. H. Lim, K. Sittampalam

^*Singapore General Hospital, Anatomic Pathology Dept., Singapore

Background & Objective: Spindle cell lipomas are characteristically located in the neck and upper back of adults, mammary type myofibroblastomas are frequently present in the breast and lower genital tract whereas cellular angiofibroma almost exclusively arises in lower genital tract region. Diagnostic confusion can result when these tumours present in unusual locations and show variant histologic features.

Method: In this poster, we present a case of highly myxoid spindle cell lipoma in the thigh of a 25-year-old female. This tumour could be mistaken for myxoid well differentiated liposarcoma or myxoid liposarcoma. The second case is that of a mammary type myofibroblastoma of the groin in a 44-year-old male. The high cellularity together with CD34 and Desmin co-expression could lead to misinterpretation and inappropriate treatment. The third case is a cellular angiofibroma arising from right femoral hernia sac in a 47-year-old female.

Results: All cases show loss of the RB gene (Monosomy 13) by using the fluorescence in situ hybridization technique. This finding coupled with careful histologic examination and proper utilization of an immunohistochemical panel, lead to correct diagnosis in all cases.

Conclusion: We have found identification of the loss of (Monosomy 13) very useful in confirming the diagnosis of spindle cell lipomas, myofibroblastomas and cellular angiofibroma especially in unusual locations.

OFP-07-006

Retinoblastoma-1 (Rb1) protein expression in smooth muscle tumours of soft tissue and female genital tract

R. Erber^*, L. Siegler, S. Burghaus, A. Hein, M. W. Beckmann, A. Hartmann, F. Haller, A. Agaimy

^*University Clinics Erlangen, Dept. of Pathology, Germany

Background & Objective: Smooth muscle neoplasms (SMN) represent one of the largest subgroups of mesenchymal tumours. Their biological subtyping into benign (leiomyoma), malignant (leiomyosarcoma) and neoplasms with equivocal features (SMN of unknown malignant potential/STUMP) can be challenging, especially in the female genital tract. Rb1 expression in non-selected SMN across the biological spectrum of these lesions has not been sufficiently studied to date. We investigated whether loss of Rb1 is a potential marker to distinguish leiomyosarcomas from benign leiomyomas.

Method: Rb1 expression was assessed in SMN using immunohistochemistry (inlcuding 2 uterine and 23 extra-uterine leiomyosarcomas, 580 conventional uterine leiomyomas on tissue microarrays, 18 fumarate hydratase (FH) deficient uterine leiomyomas and one STUMP).

Results: 23 leiomyosarcomas showed complete loss of Rb1 (92.0 %). Out of 206 LM of the TMA cohort, 205 showed variable low, frequently hardly recognizable expression of Rb1 (99.5 %). Only one case had strong Rb1 expression. No complete loss within the 206 LM was observed. All FH-deficient LMs harboured variable low Rb1 pattern (similar to conventional leiomyomas) but no complete loss.

Conclusion: Rb1 loss is observed in most unequivocal LMS, suggesting a role as a potential marker to assess malignant potential of smooth muscle tumours. However, we also found variable low expression of Rb1 that frequently seemed close to loss in almost all benign smooth muscle tumours, hardly distinguishable from complete loss. Hence, Rb1 seems to be no adequate marker to reliably separate benign from malignant smooth muscle tumours in daily routine diagnostics. The genetic basis of the reduced Rb1 pattern in benign uterine LMs needs to be further explored.

OFP-07-007

Experience in differential diagnosis of Ewing sarcoma and Ewing-like sarcoma by targeted RNA-seq

J. Diaz-Martin^*, M. Biscuola, E. Aguado, M. Delgado, A. Blaco-Lobo, D. Marcilla, E. de Alava

^*IBiS-HUVR, Molecular Pathology. Lab203, Sevilla, Spain

Background & Objective: Ewing sarcoma family of tumours (ESFT) are characterized by a canonical fusion involving EWSR1 gene in most of cases, and FLI1 as the most common partner. Ewing-like tumours (ELT) morphologically resemble ESFT but show a different clinical behavior and distinct chromosomal alterations involving CIC or BCOR genes. Therefore, differential diagnosis of ESFT and ELT upon histopathology and FISH can be challenging. Here we explored the potential of targeted RNA-seq as an ancillary technique to improve diagnostic precision.

Method: 28 cases with morphology suggestive of ESFT or ELT were FISH-probed to detect EWSR1 translocations (break apart probe). These 28 cases and 7 additional cases were studied with Archer™ FusionPlex™ Sarcoma Panel.

Results: FISH EWSR1 rearrangement was detected in 18 cases. Targeted RNA-seq identified different EWSR1-FLI1 transcripts in 17 cases, and EWSR1-NAFTC2 fusion in a single case, thus achieving 100% sensitivity. Ten cases were EWSR1 FISH negative, and targeted RNA-seq identified 3 cases expressing EWSR1-ERG, 3 cases with CIC-DUX4, 2 cases with BCOR-CCNB3, one case with EWSR1-FLI1, and one case without any fusion call. All cases without EWSR1 FISH data showed fusions consistent with a previously rendered morphologic diagnosis (ESFT or ELT).

Conclusion: Targeted RNA-seq outscores EWSR1 FISH determinations overcoming common pitfalls such us low performance in detecting EWSR1-ERG. Moreover, the RNA-seq panel simultaneously detects ELT gene fusions, circumventing singleplex FISH probing. We propose a diagnostic algorithm for differential diagnosis of ESFT and ELT in which negative EWSR1 FISH determinations are followed by an RNA-seq targeted panel assess.

OFP-07-008

Broad spectrum pathogen detection (bacteria and fungi) by NGS is a novel measure for tissue based infectious disease diagnostics

K. Kashofer^*, A. Thüringer, G. Gorkiewicz

^*Institute of Pathology, Med. Univ. Graz, Austria

Background & Objective: Diagnosis of infectious diseases is a common task in molecular pathology, but standard microbiological methods frequently fail to reveal causative pathogens. Microbial 16S rRNA gene and fungal ITS (internal transcribed spacer) sequencing by NGS has recently emerged as a versatile tool for research but can also be utilized for infectious disease diagnostics in molecular pathology.

Method: Variable regions of the bacterial 16S rRNA gene and the fungal ITS regions were amplified by PCR and sequencing was performed on Ion PGM or S5XL using the 400bp workflow. Data analysis included error correction, clustering and annotation using open source Qiime 1.8 software to facilitate microbial identification.

Results: In a four-year period we have investigated over 300 clinical cases in which classical microbiological methods failed to reveal causative pathogens. This method is especially effective in diagnosis of infectious diseases of solid organs (e.g. heart, brain, lung, liver) wherein a high percentage of atypical pathogens including rare diseases like tularemia, atypical cardiac valve endocarditis (whipple‘s disease) and polymicrobial infections could be revealed. Detection rates were very high in liver (95%) and heart (70%) specimens. In contrast, agents of putative bone and joint infections were only rarely detected, possibly due to the low bacterial load in these infections being at a level of background bacterial contamination emerging from the environment or specimen workup, sporadic contamination of reagents at the suppliers and trace amounts of bacterial DNA in enzyme cocktails.

Conclusion: Bacterial 16S rRNA gene and fungal ITS analysis is a powerful diagnostic tool for unculturable, fastidious pathogens and should be applied if classical microbiology failed to reveal causative agents in histologically suspected infectious diseases.

OFP-07-009

TERT promoter mutation and HER2 gene amplification in malignant peripheral nerve sheath tumours: is there a molecular signature playing role in malignant transformation?

S. Kantarcioglu Coskun^*, M. Gamsizkan, I. Yilmaz, U. Yalcinkaya, M. A. Sungur, S. Buyucek, B. Onal

^*Duzce University, Pathology, Turkey

Background & Objective: Benign and malignant (MPNST) peripheral nerve sheath tumours may occur sporadically or related to neurofibromatosis (NF). Unless the mechanisms of tumourogenesis NF related cases are better understood, still remained unclear in sporadic cases. We aimed to investigate genetic route of tumour in both individuals with NF-1 and sporadic ones to open a way for targeted therapies in the future.

Method: We investigated the role of HER2 with Dual ISH DNA Probe Cocktail test; BRAF (exon 15) and TERT promoter mutation frequency with Sanger sequencing method in respectively 25 sporadic neurofibroma, 25 neurofibromatosis type-1 (NF-1) related neurofibromas and 25 MPNST cases from two institutes.

Results: We identified TERT promoter mutation only in one sporadic MPNST (% 4) and no BRAF mutation in any case. There were gene amplification of Her2 in 10/25 (% 40) MPNST cases. No mutations or gene amplification detected in neurofibromas (sporadic or NF-1 related) (p<0,001)

Conclusion: MPNSTs are sarcomas with poor prognosis and limited treatment options. TERT gene have been demonstrated to be absent in benign tumours and normal subjects, implicating their potentially critical roles in human carcinogenesis. Epidermal growth factor receptor (EGFR) may play a putative role in MPNST pathogenesis and be targeted for therapeutic purposes. There are very few studies assessing BRAF and TERT promoter mutations and increasing Her2 gene dosage in patients with MPNST and there is no enough data in literature to determine a molecular signature plays key role in malign transformation both sporadic and NF-1 related cases.

OFP-07-010

Mutation analysis in H3F3A and H3F3B genes in giant cell tumour of bone and chondroblastoma

A. Tysarowski^*, M. Wagrodzki, K. Seliga, J. A. Siedlecki, M. Prochorec-Sobieszek

^*Cancer Center Institute, Dept. of Pathology, Warsaw, Poland

Background & Objective: Giant cell tumour of bone (GCT) represents approximately 5% of primary bone tumours and about 20% of benign bone lesions. The frequency of the other tumour- chondroblastoma (CHB) is significantly lower and the tumour is identified in about 1% of primary bone lesions. In both tumours giant cells are present and differential diagnosis of both of them is challenging. It has been observed that, in contrary to other bones tumour, specific mutations in genes H3F3A (p.Gly34Trp and p.Gly34Leu) and H3F3B (p.Lys36Met) encoding histone H3.3 are present in GCT and CHB, respectively. The aim of the study was to evaluate the usefulness of H3F3A and H3F3 B genes genotyping in the diagnosis and differentiation of GCT and CHB bone tumours.

Method: The occurrence of p.Gly34Trp, p.Gly34Leu mutations in H3F3A and p.Gly34Trp in H3F3B was studied using Sanger sequencing in FFPE specimens from 106 tumours (classified according to standard radiological and pathological criteria as GCT- 99 cases and CHB-7 cases).

Results: In 98/99 (99%) of GCT cases H3F3A mutations were present, with predominance of p.Gly34Trp (97 cases) vs p.Gly34Leu (1 case). In 7/7 (100%) cases of CHB the p.Lys36Met mutation in H3F3B was present.

Conclusion: Our observations further confirm the data, previously reported by others, that mutations in genes H3F3A and H3F3B are present in GCT and CHB, respectively. Therefore, molecular analysis is an effective, fast and valuable step in differential diagnostics of those tumours.

OFP-07-011

Evaluation of CD4 (helper T-lymphocytes) and CD8 (cytotoxic T-lymphocytes) in cervical epithelium and stroma of HIV-positive patients

M. Brito^*, M. J. Brito, C. Martins, F. Ventura, A. Félix

^*Hospital Garcia de Orta, Anatomia Patologica, Almada, Portugal

Background & Objective: In HIV+ patients, a compromised CD4+ T cell function has been described as the inducer for HPV-associated cancer occurrence. Our aim was to evaluate the distribution of CD4 (Helper T Lymphocytes) and CD8 (Cytotoxic T Lymphocytes) in cervical epithelium and stroma of HIV+ patients with Intra-Epithelial Squamous Lesions (SIL).

Method: Thirty-eight histological specimens of 21 HIV+ patients (24 Low Grade SIL and 14 High Grade SIL) were studied by immunohistochemistry to CD4 and CD8 (Ventana, Roche Diagnostics). Scoring of immune stained positive lymphocytes were counted in five randomly selected high power fields at 40X magnification and the counts were averaged. CD4+ and CD8+ positive cells were recorded as: score 1 (1-25 cells), score 2 (26-50 cells), and score 3 (≥51 cells), in the tumour and the stroma, separately. Results were analysed by Chi-Square test and Fisher’s exact test, using Graph Pad Prism 6 (statistical significance for p<0.05).

Results: No significant differences were observed for the presence of CD4 + cells in epithelium and stroma, between women with HSIL and LSIL. As for CD8+ cells, the HSIL group presented significant higher scores in epithelium (p=0.011). In stroma, when considering the scores 1 and 2 together versus score 3, women with HSIL also presented significantly higher scores for CD8+ cells (p=0.027).

Conclusion: Our results support that alterations in T lymphocytes are present in the cervix of HIV+ patients with SIL. A higher density of CD8+ cells in the stroma of HSIL may indicate a more antigenic stimulation of these lesions in the interaction with stroma.

Monday, 10 September 2018, 17:15 - 19:15, Room A2

OFP-08 | Joint Session: Neuropathology / Ophthalmic Pathology

OFP-08-001

Implementation of methylation array-based classification of paediatric central nervous system tumours in routine diagnostic pathology

S. M. Al-Qahtani^*, A. Shamikh, C. Illies, E. Basmaci, G. Prochazka, G. Ljungman, T. Díaz De Ståhl, M. Nistér

^*Karolinska Institutet, Oncology and Pathology, Spånga, Sweden

Background & Objective: For the sake of diagnostic accuracy, the current guidelines emphasize on the integration of molecular and histological features of central nervous system (CNS) tumours. Recent reports have revealed that such integration could be achieved by methylation arrays. The methylation array-based classification of paediatric CNS tumours was implemented at the Swedish Childhood Tumour Biobank as part of the quality assessment. The results provide a level of objectivity to include methylation profiling in routine diagnostic pathology.

Method: The DNA was extracted and analyzed by 450K/EPICS array hybridization. Automated reports are then generated using the classifier at MolecularNeuropathology.org. Finally, the histopathological and classifier diagnoses are reviewed and integrated. The samples included 42 paediatric CNS tumours: glial, neuronal, embryonal, tumours of nerves, germ cell, meningioma and mesenchymal tumours.

Results: Out of 42 samples, 32 (76.2%) were matched (score>0.9) with the classifier (Version 11b4). The matching outcomes were (i) confirmation of the histopathological diagnosis in 30 cases (93.8%); (ii) new diagnosis in 2 cases; and (iii) misleading results no cases. The two cases were re-evaluated resulting in correction of histopathological diagnosis in one case while the other case was not improper histopathological diagnosis but a new entity that is not recognized yet by the WHO classification of CNS tumours.

Conclusion: Implementation of the technique in routine diagnostic practice is not complicated, and highly useful. Classifier’s diagnoses are according to the 2016 WHO. Profiling the methylome is robust, reproducible, needs representative samples, and most of the mismatching scores (<0.9) was due to lack of reference cases.

OFP-08-002

Atypical meningiomas: Which histopathological features correlate with recurrence risk?

V. Barresi^*, S. Lionti, S. Caliri, M. Caffo

^*University of Messina, Dept. of Human Pathology, Italy

Background & Objective: Atypical meningiomas are currently defined by: 1) at least three "minor atypical criteria"; or 2) mitotic count equal or higher than 4 mitoses per 10 HPF (high mitotic index); or 3) brain invasion. 5-year disease free survival (DFS) of patients with atypical meningioma is around 50%. Due to their heterogeneous behavior, the post-surgical treatment of atypical meningiomas is controversial. Although radiotherapy could be effective in reducing recurrence risk, adverse effects could be spared in patients who would not develop recurrences. This study aims to investigate which histopathological features may significantly predict recurrence risk of atypical meningiomas.

Method: We reviewed the histological slides and clinical data of 58 atypical meningiomas in our archive between 2005 and 2014. By applying strict definitions for minor criteria, 14 cases were excluded. Thus, we investigated the correlation between histopathological features and recurrence or disease-free survival (DFS) in 44 atypical meningiomas.

Results: meningiomas classified as atypical only on the presence of minor criteria had low recurrence risk. Brain invasion, high mitotic index and sheeting were significantly associated with recurrence (P= 0,004; P= 0,029; P= 0,007). However, the co-presence of sheeting and high mitotic index, with or without brain invasion, had the highest ability to identify recurring meningiomas (P= 0,0001) (sensitivity: 90,6%; specificity: 83,3%).

Conclusion: Our results suggest to re-consider classification of meningiomas as atypical based only on minor atypical criteria. The co-occurrence of sheeting and high mitotic count, with or without brain invasion, may be useful to identify high risk cases which may benefit from adjuvant treatments.

OFP-08-003

Alternative BRAF-activating mutation in pleomorphic xanthoastrocytomas

E. Trisolini^*, L. Poles, I. Morra, C. Manini, R. Nunziata, A. Fanti, A. Gerosa, R. Boldorini

^*University of Eastern Piedmont, Health Sciences, Novara, Italy

Background & Objective: Pleomorphic xanthoastrocytoma (PXA) is a rare low-grade glial tumour, commonly affecting children and young adults, with a 80% 5-year survival; few cases show anaplastic features (WHO grade-III) and had a worse prognosis (30% 5-year survival). Molecular characterization indicates frequent BRAFV600E mutation (up to 70%), whereas other genetic alterations, like BRAF and RAF1 fusions, were rarely reported. In a small cohort of patients with PXA, we performed a sequencing analysis of target genes in order to investigate the presence and frequency of druggable mutations.

Method: The mutational status of BRAF exon 15, FGFR1 exons 12 and 14, TERT promoter, codons R132-IDH1 and R172-IDH2, was evaluated among 13 PXA surgical cases (8 WHO grade-II, and 5 grade-III) by Sanger sequencing. In one patient both the primary tumour (PXA grade-II) and recurrent (PXA grade-III) were examined.

Results: BRAFV600E mutation was detected in 5 cases (38%) (3 grade-II and 2 grade-III) and BRAFT599_V600insT in 3 cases (23%) (2 grade-II and 1 grade-III). Interestingly, one of BRAFT599_V600insT was identified in the recurrent PXA grade-III but not in the primary grade-II tumour. Two PXA grade-III (15%) showed C228T TERT promoter mutation and a BRAF wild-type genotype. No IDH1, IDH2 and FGFR1 mutation were identified.

Conclusion: Our study indicated that BRAFT599_V600insT has a high frequency in PXA. Since it shows similar behavior of V600E mutation, it could be considered as therapeutic target by BRAF and MEK-inhibitors. TERT promoter mutation seems related to anaplastic phenotype, but further studies are needed to establish its prognostic significance.

OFP-08-004

Frequency of actionable molecular drivers in lung cancer patients with CNS metastases

C. Mawrin^*, B. Hanke, E. Kirches, H.-U. Schildhaus

^*University Hospital Magdeburg, Neuropathology, Germany

Background & Objective: Brain metastases are frequently in lung cancer patients. Treatment options are limited, and detailed information about the frequency of molecular alterations representing potential treatment targets is crucial.

Method: We have analyzed a consecutive series of 133 patients (86 male, 47 female) with lung cancer metastases to the central nervous system. Biopsy material was characterized by fluorescence in situ hybridization (FISH) to detect alterations (EML4/ALK, MET, FGFR, ROS, RET) and EGFR (exon 18-21) using the COBAS system. Overexpression of ALK was detected by immunohistochemistry (Ventana).

Results: ALK expression was detected in 8/133 tumours (6%). Among 117 tumours with suitable material for EML4/ALK FISH, the translocation was found in 3 cases (2.56%). MET amplification was detected in 37/127 cases (29.1%). RET amplification was detected in 2/106 cases (1.9%). ROS amplification was seen in 1/104 cases (0.9%). FGFR1 amplification was detected in 6/92 cases (6.5%). EGFR mutations were detected in 7 of 132 patients studied (5.3%). Comparing alterations of EGFR and EML4/ALK with the primary tumour in 20 patients, one patient had an EM4/ALK translocation in the primary tumour which was not detectable in the CNS metastasis, while the remaining alterations were similar (concordance rate 95%).

Conclusion: Lung cancer metastases are characterized by a high frequency of MET amplifications. EML4/ALK translocation and EGFR mutation rates are within the expected frequencies known from primary tumours. There seems to be a high concordance between primary and CNS metastatic tumour. Detailed molecular characterization of CNS metastases is essential to offer additional treatment options to the patients.

OFP-08-005

Primary gliosarcoma with IDH1 mutation and codeletion of 1p and 19q

H.-Y. Lee^*, C. S.-Lyn Ding, N. L. Chilagondanahalli, B. C.-Shern Ho, Y.-H. Ho, K.-L. Chuah

^*Tan Tock Seng Hospital, Pathology, Singapore, Singapore

Background & Objective: In the 2016 WHO classification of tumours of the central nervous system, gliosarcoma is a variant of isocitrate dehydrogenase (IDH)-wildtype glioblastoma with a 5-year survival rate of less than 10%. Although mention is made of gliosarcoma arising in oligodendroglioma (“oligosarcoma”), IDH-mutant and 1p/19q-codeleted gliosarcoma is not a codified entity. We present a case of primary gliosarcoma with IDH1 mutation and 1p/19q codeletion.

Method: In 2010, a 38-year-old male presented with a right frontal lobe brain tumour. Excision showed a gliosarcoma with morphologically malignant astrocytic and spindle cell sarcomatous components. O[6]-methylguanine-DNA methyltransferase (MGMT) promoter was methylated. He was treated with adjuvant temozolomide and radiotherapy. Tumour recurrence was detected 7 years later on follow-up neuroimaging. Re-excision in 2017 showed a recurrent high-grade glioma with astrocytic morphology. No sarcomatous or oligodendroglial component was seen in the recurrent tumour. R132H mutation-specific IDH1 was positive in the recurrent tumour and in the gliomatous and sarcomatous components of the original tumour. Fluorescence in situ hybridisation performed on the recurrent tumour showed a combined deletion of 1p36 and 19q13. No confirmation of whole-arm deletions of 1p/19q was available. Review of the original tumour showed focal areas resembling oligodendroglioma.

Results: This primary gliosarcoma with IDH mutation, 1p/19q codeletion and foci resembling oligodendroglioma, suggests that rarely, primary gliosarcoma may share the genotype and phenotype of an oligodendroglial tumour, with prolonged patient survival.

Conclusion: The current classification categorises gliosarcoma as a variant of IDH-wildtype glioblastoma with similarly dismal prognosis. However, gliosarcoma may be biologically more heterogeneous, with “oligosarcoma” possibly being less aggressive.

OFP-08-006

Morphological and immune histochemical alterations of astrocyte neuroglia of epiphysis under conditions of long-term influence of heavy metals salts on the organism

A. Romaniuk^*, N. Hryntsova, O. Romaniuk, M. Lyndin, L. Karpenko

^*Sumy State University, Pathology, Ukraine

Background & Objective: It was studied the morphological and immune histochemical alterations of the glial component of the epiphysis under conditions of long-term influence of heavy metal salts in the experiment.

Method: The experiment was conducted on 24 rats aged 5-6 months (1 control and 1 experimental group). For 90 days animals received drinking water, saturated with a combination of heavy metals salts: zinc, copper, iron, manganese, lead and chromium. It was applied a common method of histological examination. Immune histochemical diagnosis of the Ki-67 proliferation marker was performed using rabbit monoclonal antibodies.

Results: Heavy metals salts cause morphological and immune histochemical alterations in all structural components of the epiphysis. Significant vascular enlargement with a violation of the rheological properties of the blood and the formation of blood stasis, the aggregation of erythrocytes, the sludge phenomenon, rare diapedesic hemorrhages. In the subcapsular zone, an explicit reactive astrocyte glial reaction is observed. Especially active proliferators are formed around the vessels of medium diameter in the peripheral regions of the gland. The evaluation of the expression level of the Ki - 67 proteins revealed its moderate proliferative activity in astrocytes of peripheral regions (35-40%).

Conclusion: The long-term effect on the body of rats of heavy metal salts causes local reactive astrocyte gliosis in the epiphysis of rats, which may be explained by the neuro protective properties of astrocytes in response to the action of the stressor agent.

OFP-08-007

Craniopharyngiomas: 20-year-period evaluation study

P. Zdravkovski^*, B. Ilievski, V. Janevska, R. Jovanovik, P. Cvetkovski, V. Mirchevski, V. Rendevski, V. Aliji, M. Zdravkovska, G. Petrusevska

^*Medical Faculty - UKIM, Institute of Pathology, Skopje, Republic of Macedonia

Background & Objective: Craniopharyngioma is a rare histologically benign brain tumour with potential malignant clinical course because of the high propensity of recurrence, deriving from the remnants of Rathe’s pouch, presenting as solid mass and partly as fluid-filled cyst. There are two main histological subtypes: adamantinous and papillary. The aim of this study is to evaluate statistical features of this tumour in the Republic of Macedonia.

Method: This is a 20-year-period retrospective evaluation study (1998-2018) of 40 craniopharyngioma cases operated in the University Neurosurgery Clinic, diagnosed at the Institute of Pathology, Medical Faculty-UKIM, Skopje, Macedonia on paraffin-embedded section slides routinely stained with H&E. Statistica for Windows 7 was used.

Results: From total 4929 cases of benign and malignant brain tumours, craniopharyngioma comprise 40 cases (0,81%); 25(62,5%) males (37,9±17,8 years), 15(37,5%) females (34,0±25,4 years), age 3 to 68 years; most common localization: sellar region - 11(27.5%), cerebrum – 8(20%). Adamantinous - 27(67,5%) cases, papillary 13(32,5%) cases. Age group distribution: the most cases - 7(17,5%) in 0-9, 40-49, 60-69 years groups; least cases – 3(7,5%) in 20-29 years group. Nine (22,5%) of 40 patients have had recurrent tumour (first 1-3 years). Adamantinous was diagnosed in 14(51.85%) males and 13(48.15%) females; papillary in 11(84.62%) males and 2(15.38%) females. There is significant statistical difference between age groups and craniopharyngioma subtypes (Kruskal-Wallis ANOVA: H = 14,86; p = 0,0274).

Conclusion: We found association and correlation between gender, age and histological subtype. Papillary craniopharyngioma appears more frequently in males and adamantinous was most prevalent in younger patients.

OFP-08-008

PD-L1 expression of medulloblastoma

P. Cakmak^*, E. Kolay, A. Poyraz

^*Gazi University, Pathology, Ankara, Turkey

Background & Objective: Medulloblastoma is the most common central nervous system embryonal tumour. Treatment protocols include surgery with the goal of gross total excision if possible, craniospinal radiation therapy, and adjuvant chemotherapy. Patient who do survive often experience significant neurologic impairment due to unavoidable side effects of cytotoxic therapy. Immunotherapy can be another option to kill cancer cells and has less side effects compared to other treatment protocols. The aim of the present study was to examine the expression of PD-L1 in medulloblastoma, and to predict immunotherapy response.

Method: 50 cases were included in this study. We analyzed immunohistochemical PD-L1 (clone SP142) expression in all cases. We used tonsil as a positive control.

Results: We couldn’t detect PD-L1 expression in any of our cases.

Conclusion: Our result suggests that medulloblastomas won’t have any benefit from treatment strategies with PD1/PD-L1 blockers.

OFP-08-009

Demographic and pathological characteristics of medulloblastoma: single center experience

E. Kolay^*, P. Cakmak, A. Poyraz

^*Gazi University, Pathology, Ankara, Turkey

Background & Objective: Brain tumours are still under investigation in terms of prognostic factors. Some tumours have newly discovered molecular alterations. For medulloblastoma there is both histological and molecular classification in WHO classification of tumours of the central nervous system revised 4th edition. Although molecular classification has increasing clinical utility, histopathological classification has also been retained, due to its clinical utility when molecular analysis is limited or not feasible.

Method: We reviewed 50 medulloblastoma cases in our institution between the years 2008 and 2018 and collected their data about gender, age, histology, metastasis status, resection procedure and survival status.

Results: The median patient age at diagnosis was 4. Male to female ratio was 1,45. Tumours were located in the cerebellar parenchyma or grew into the fourth ventricle in 49 patients. One case had tumour in thoracic spine. 14 patients underwent gross total resection while others underwent subtotal resection or biopsy. 35 patients have been followed up in our center and 18 of them had progression free survival. 9 of them died and 8 of them had recurrent tumour or leptomeningeal spread although they received chemoradiotherapy. 41 cases were histologically classic subtype and 6 cases were desmoplastic/nodular, 2 cases are largecell / anaplastic and one case was medulloblastoma with extensive nodularity.

Conclusion: Current surgical approaches and therapy regimens increase the progression free and overall survival rates. Although newly described molecular parameters can be helpful for prediction of prognosis and development of new therapy strategies, histopathology maintains its importance.

OFP-08-010

Expanding on WHO guideline compliant molecular testing of central nervous system tumours by low density whole genome sequencing

K. Kashofer^*, I. Halbwedl, E. Winter, G. Hoefler, M. Asslaber

^*Institute of Pathology, Med. Univ. Graz, Austria

Background & Objective: Classification of CNS gliomas has been revised with current WHO guidelines incorporating several molecular features. Current guideline compliant molecular testing incorporates NGS panel sequencing, methylation screening and copy number variation (CNV) measurement. MPLA, qPCR and analysis of NGS amplicon sequencing depth are established methods to detect 1p19q codeletion in CNS tumours. However, these methods summarily fail to detect CNVs in other regions. We have introduced low density whole genome sequencing as a diagnostic routine tool for comprehensive mapping of all CNV events.

Method: Tumour DNA was processed using the Ion Torrent Fragment Library Kit and sequenced on Ion Proton to yield approximately 1-2 million reads. Data were analyzed with the open source R package „CNAnorm“.

Results: In two years we have analysed 95 gliomas and demonstrate that beside 1p19q codeletion, typical gains and losses of chromosomes indicate the histological WHO grade. Additionally, in high grade gliomas also histologically low-grade tumour areas carry the high-grade copy number alterations. Furthermore, prediction of time to recurrence with CNV alterations is superior to histological WHO grade.

Conclusion: Low density whole genome sequencing is a versatile method to detect CNVs in gliomas and supports WHO grading. It provides clinically relevant information and can be used to predict recurrence free survival.

OFP-08-011

Comprehensive diagnosis and monitoring of uveal melanoma with gene panel analysis, low density whole genome sequencing and digital droplet PCR

K. Kashofer^*, A. Thüringer, I. Halbwedl, M. Asslaber, W. Wackernagel

^*Institute of Pathology, Med. Univ. Graz, Austria

Background & Objective: Uveal melanoma is the most common malign tumour originating from the eye with an incidence of 400-500 patients per million. Molecular features include mutations in several genes as well as losses and gains of specific chromosome arms. Molecular diagnosis of uveal Melanoma is hampered by difficult sample extraction and low tumour volumes for diagnostic purposes. While local tumour control after radiotherapy is high (80-95%), about 45% of patients develop metastatic disease.

Method: We have established a NGS Panel to analyze mutations in nine genes by Ion Torrent NGS. Additionally, copy number variation is detected by low density whole genome sequencing. Digital droplet PCR (QX200) utilizing primers for the very common GNAQ and GNA11 mutations have been established and validated for liquid biopsy analysis.

Results: Since introduction of the method to routine diagnostics we have investigated 28 cases of uveal melanoma. Tumour tissue was collected by vitrectomy using biopsy forceps. NGS analysis revealed specific genetic aberrations in 28/28 tumours (100%). Mutational spectrum was in concordance with literature (GNAQ 46%, GNA11 39%, BAP1 36%, EIF1AX 32%). CNV analysis revealed frequent loss of chromosome 3 (46%), gain of chromosome arm 8q (25%) and other common aberrations. After initial diagnosis plasma samples were collected at 3 months intervals. Digital droplet PCR liquid biopsy analysis was performed in select cases with suspected metastases. Circulating tumour DNA was only detected in one case with clinically manifest progression to metastatic disease.

Conclusion: Combined analysis of mutations and copy number aberrations from uveal melanoma is possible even with little available tumour material and is important for clinical risk management and proper treatment monitoring.

OFP-08-012

MicroRNA in conjunctival melanocytic lesions

J. van Ipenburg^*, A. Gillis, L. Dorssers, Q. van den Bosch, N. Naus, R. van Ginderdeuren, G. Missotten, D. Paridaens, R. Verdijk, L. Looijenga

^*Erasmus Medical Center, Pathology, Rotterdam, The Netherlands

Background & Objective: The management and stringent follow up for conjunctival melanocytic neoplasia emphasizes the need for early identification of aggressive lesions. Therefore, differences in microRNA expression between benign and malignant conjunctival lesions were studied.

Method: The microRNA profiles from FFPE samples of six conjunctival nevi and twenty conjunctival melanomas with or without metastasis were determined using the Taqman Low Density Array (TLDA) approach (377 miRNA targets plus controls). The minimal follow up for the non-metastatic lesions was 10 years. Amplification data were processed using the Cloud App (ThermoFisher Scientific) and analysed using QbasePlus (Biogazelle N.V., Zwijnaarde, Belgium). The benign lesions were compared with the malignant lesions and the metastatic lesions to the non-metastatic lesions. Both supervised and unsupervised clustering was performed. The differentiating microRNAs were verified using single assay qRT-PCR and validated using an independent cohort consisting of sixteen nevi and twenty melanomas.

Results: The data did not identify significant difference in miRNA levels between the conjunctival melanomas with or without metastases. In contrast, seven miRNAs were significantly different between conjunctival nevi compared to melanoma. Using single assay qRT-PCR, these results could be reproduced for five miRNAs. Validation of these miRNAs in an independent cohort of nevi and melanomas confirmed the significance (Fold Change>4, P<0.004, corrected for multiple testing). The area under the Receiver Operator Curve for each of these miRNA was over 0.85.

Conclusion: We, for the first time, demonstrate existence of prognostic microRNAs for conjunctiva melanocytic lesions, possible of interest for further development and clinical implementation.

Tuesday, 11 September 2018, 08:30 - 12:00, Room A4

OFP-09 | Breast Pathology

OFP-09-001

What is the ideal Ki67 hot spot definition in breast cancer?

S. Robertson^*, M. Lippert, J. Hartman

^*Karolinska Institutet, Dept. of Oncology-Pathology, Nacka, Sweden

Background & Objective: Tumour proliferation is one of the hallmarks of cancer. The proliferation associated nuclear marker Ki67, a predictive and prognostic biomarker in breast cancer, is used to guide clinical decisions concerning adjuvant chemotherapy. However, the international recommendations for Ki67 are controversial due to the lack of standardization and there is no international consensus regarding Ki67 cut offs and hot spot definitions. The aim of this study is therefore to define the Ki67 hot spot using a machine learning approach for digital image analysis with correlation to prognostic value.

Method: In this study, two Swedish breast cancer cohorts (n=897) with scanned whole slide images of parallel sections with invasive tumour were stained with haematoxylin-eosin, pancytokeratin (CKMNF116) and Ki67 and analysed using a digital image analysis software from Visiopharm A/S. Image analysis was performed on aligned pancytokeratin and Ki67 images for accurate tumour identification. Clinicopathological data was included as well as outcome data for one of the cohorts.

Results: We used a machine learning approach with unsupervised learning to define Ki67 hot spots in breast tumours. Hot spots were identified as specified area with highest ratio of positive Ki67 compared to unstained pancytokeratin-positive tumour cells. Our results show significant variations in Ki67-index depending on number of included tumour cells, hot spot size, shape and location.

Conclusion: Identification of a hot spot definition based on maximal prognostic value has significant clinical implications and has the potential to affect guidelines for proliferation-assessment in breast cancer.

OFP-09-002

Intraoperative diagnosis of breast cancer sentinel lymph nodes by scrape cytology: diagnostic accuracy and cost-effectiveness

A. Villar Fernández^*, A. Ballén Barragán, J. L. Pérez López, J. M. Ródriguez Barbero, M. Granados Alamillo, R. Granados Carreño

^*Hospital de Getafe, Anatomía Patológica, Madrid, Spain

Background & Objective: The intraoperative (IO) analysis of sentinel lymph node (SN) in breast cancer surgery relies on time and resource-consuming procedures for Pathology Departments. We analyze the diagnosis´efectiveness of a rapid and cost-saving IO cytology method.

Method: A retrospective study was performed with IO analysis of 1013 SNs from 606 patients obtained between 2010-2017. Cytological IO diagnosis was used after scraping all surfaces from the sectioned nodes, smearing onto glass slides and staining with Diff-Quick®. Frozen section was analyzed only when tumour metastasis was cytologically suspected. Cost estimation of the alternative worldwide-used molecular OSNA technique was applied to our work load.

Results: The prevalence of macrometastases in SNs was 9,9% (100/1013). There were no false positive cases and diagnostic accuracy was 98,4%. In 13/606 patients (2,1%) the method failed to detect macrometastes (false negative) and a second surgical procedure was needed for axillary dissection, (average of 1,6 cases/year). The approximate time spent in the IO diagnosis by this method was 15 minutes per node. No molecular analysis (OSNA) was performed, with an estimated annual cost saving of 150.000€/year.

Conclusion: Although a pathologist-dependent technique, the IO analysis of SN by scrape cytology in Pathology Departments reaches an excellent diagnostic accuracy with very low false negative rate and no false positive diagnoses. Besides being a safe and rapid technique, its use represents an important cost reduction when compared to molecular analysis, particularly with the recent consensus to spare axillary dissection in women with less than 3 nodes with metastatic disease.

OFP-09-003

Somatostatin receptor expression in neuroendocrine breast cancer

R. Terlevic^*, M. Peric Balja, D. Tomas, B. Kruslin, S. Vranic, F. Skenderi, A. Demirovic

^*Pula General Hospital, Pathology and Cytology, Croatia

Background & Objective: Neuroendocrine breast cancer (NEBC) is a group of rare tumours which could benefit from therapy approaches targeting the somatostatin receptor (SSTR). In particular, SSTR2A and SSTR5 are potential targets given their relatively consistently increased expression in gastrointestinal and pancreatic primary and metastatic neuroendocrine tumours. Currently, there are no studies describing the expression of SSTRs in NEBC. The purpose of our study was to characterize the immunohistochemical expression of SSTR2A and SSTR5 in NEBC.

Method: A retrospective series of 31 NEBC cases was analyzed, and SSTR2A and SSTR5 immunohistochemistry performed.

Results: The mean age of our population was 67 years (sd=15). Median tumour diameter was 21 mm, and the median histological grade was 2. SSTR2A showed weak positivity in 11 cases (35%), mild positivity in 6 cases (19%) and strong positivity in 5 cases (16%). Nine cases were negative for SSTR2A (29%). SSTR5 showed weak positivity in 16 cases (52%), mild positivity in 6 cases (19%), while no cases showed strong positivity. Nine cases were negative for SSTR5 (29%).

Conclusion: To our knowledge this is the first description of SSTR expression in BCNF. In our series, SSTR2A and SSTR5 were consistently expressed in BCNF. Most cases showed weak expression. These results need to be further validated in a larger series including metastatic disease, in order to provide possible therapeutic targets for patients with advanced disease.

OFP-09-004

Elastic stains in the evaluation of DCIS with comedo necrosis in breast cancers

T. Zombori^*, G. Cserni

^*University of Szeged, Pathology, Hungary

Background & Objective: As concerns the microscopic morphology of ductal carcinoma in situ (DCIS), neoplastic cells are surrounded by both a myoepithelial cell layer and a basement membrane as expected from the outer structure of ducts and lobules. However, in some cases it is impossible to state whether the structures involved by the disease are ducts or lobules.

Method: All anatomic structures involved by DCIS displaying comedo necrosis (seen on both haematoxylin and eosin stained and orcein stained slides) were identified as representing ducts, likely ducts, unclassifiable structures, likely acini or acini on the basis of their distribution and resemblance to normal anatomic structures. All structures were then rated as having a circumferential elastic layer (as normal ducts), a partial elastic layer around more or less than half of the periphery or having no peripheral elastic layer at all (as normal acini).

Results: Altogether 1220 anatomic structures were classified from 27 slides of 21 patients. Structures classified as ducts or likely ducts were likely to have an elastic coating, whereas acini and likely acini had no such coating. Unclassifiable structures were generally devoid of an elastic layer. Structures (and cases) that were likely to represent neoductgenesis as proposed by Zhou et al (Int J Breast Cancer 2014;2014:581706.) were generally unclassifiable and devoid of outer elastic layer.

Conclusion: Many duct-like structures in DCIS with comedo necrosis are devoid of elastic layer typical of normal ducts, suggesting that these structures are abnormal despite conservation of the myoepithelium and the basement membrane.

OFP-09-005

Transcriptional profiling of endocrine resistant versus sensitive breast cancer uncovers gene expression programmes associated with therapeutic response

C. Schagerholm^*, S. Robertson, K. Govindasamy-Muralidharan, J. Lövrot, X. Chen, J. Hartman

^*Karolinska Institutet, Dept. of Oncology-Pathology, Stockholm, Sweden

Background & Objective: The majority of breast tumours express the oestrogen receptor alfa (ER) and responds to adjuvant endocrine therapy. Endocrine therapy blocks or down-regulates ER and in turn causes inhibition of cancer cell proliferation and reduces risk of metastasis. Still, many patients do not respond to endocrine therapy in the adjuvant setting and even more metastatic patients will progress to an endocrine refractory state. No method exists to accurately predict therapeutic response but would be highly desired in the clinical situation. The overall purpose of this study was to analyse gene expression of ER-positive tumours from endocrine therapy resistant patients versus sensitive patients with the aim to identify gene expression signatures corresponding to therapeutic sensitivity and resistance.

Method: The cohort comprised 22 cases with consecutive relapses (ER+ primary tumours receiving adjuvant endocrine therapy, with ER+ breast cancer relapse during ongoing therapy) and 44 matched controls (ER+ primary tumours of patients with good outcome on adjuvant endocrine therapy), retrospectively identified through the Karolinska University Laboratory pathology LIS-system. From all retrieved tumours RNA was extracted and analysis by Affymetrix gene array was performed.

Results: We identified unique gene expression patterns in the endocrine resistant tumours. Furthermore, endocrine resistance was associated with specific transcriptional biological programs. A second validation cohort is now designed with ongoing analysis to confirm the findings.

Conclusion: Our data indicates that endocrine resistance in primary breast cancer is associated with unique transcriptional profiles that can be further utilized as therapy predictive biomarkers.

OFP-09-006

High reproducibility in Ki67 assessment in luminal breast cancers enabled by French recommendations and digital image analysis

C. Bénière^*, R. Rouzier, J.-P. Bellocq, Y. Allory, J.-M. Guinebretière

^*Institut Curie, Pathology, Saint-Cloud, France

Background & Objective: Luminal breast carcinomas express hormone receptors and show variable aggressiveness potential and response to adjuvant chemotherapy. A proliferation marker, Ki67, is useful to categorize these lesions but the reproducibility of its assessment is controversial. The French association of quality insurance in pathology (AFAQAP) published guidelines for Ki67 counting in breast cancers taking into account intra-tumour heterogeneity. Our objective was to study the performances of digital image analysis (DIA) using these recommendations and to compare the results to the Prosigna® molecular signature.

Method: In this prospective and multicentric study, 200 invasive breast carcinomas, ER and/or PR positive, Her2 negative, stage T1/T2, N-, were included. Ki67 (MIB1) staining and the Prosigna® molecular signature were centralized. Ki67 labelling index was assessed by manual counting according to the AFAQAP recommendations by one pathologist and with DIA by two pathologists.

Results: Interobserver reproducibility of DIA was r=0.93 [IC95 0.89-0.95, p<2.2e-16]. Intraobserver reproducibility between manual counting and DIA was r=0.87 [IC95 0.83-0.90, p<2.2e-16]. Using a cutoff of 20%, manual and DIA counting properly assigned 80% and 76% of tumours to the luminal A and B categories defined by Prosigna®. Counting time per 100 cells was 34% quicker with DIA than manually (14 vs. 21 seconds).

Conclusion: The AFAQAP recommendations for Ki67 counting achieved an excellent interobserver reproducibility with DIA, including heterogeneously stained tumours. There was a good correlation between Ki67 and the Prosigna® molecular signature. These recommendations are applicable to DIA, which reduces counting time.

OFP-09-007

Tumour-infiltrating lymphocytes in triple-negative breast cancer correlate with morphology, Bcl2 expression, proliferative activity and menopausal status

M. Koleckova^*, Z. Kolar, J. Ehrmann, G. Korinkova, R. Trojanec, I. Uberall

^*Faculty of Medicine Olomouc, Pathology, Czech Republic

Background & Objective: Triple-negative breast carcinomas (TNBCs) are morphologically a heterogeneous group of breast carcinomas with no or minimal estrogen/progesterone hormone receptor HER2 expression. In this study, we characterized the types and intensity of tumour infiltrating lymphocytes (TILs) in TNBCs obtained from mastectomies and correlated the results with tumour morphology and other clinicopathological parameters.

Method: We re-examined the samples of 3,544 breast cancers (2007-2017) and selected 413 TNBCs of which 61 were of those without neoadjuvant therapy. The type and intensity of lymphocyte infiltration was correlated with morphological features including spindle cell or apocrine metaplasia, tumour grade, lymph node involvement, relapse of disease, Bcl-2 expression status, proliferative activity measured by Ki67 expression, age and menopausal status.

Results: The majority of samples were invasive carcinomas NST with medullary features according to WHO classification 2012, with central necrosis/fibrosis, tendency to spindle cell and/or apocrine metaplastic differentiation and extensive lymphocytic infiltration. We found a tendency to positive correlation between the quantity of surrounding TILs and tumour size as well as statistically significant (p<0.05) positive correlation with tumour grade, proliferative activity, Bcl-2 expression and menopausal status. We also found an association of Bcl-2 over-expression and metastatic potential with apocrine tumour transformation. No correlation between TILs and other clinicopathological parameters was revealed.

Conclusion: The intensity of TILs considered together with specific morphological and expression features of TNBC may predict clinical outcome.

OFP-09-008

SOX10 expression in invasive ductal carcinomas of the breast and benign breast tissue

K. Chiu^*, D. Ionescu, M. Hayes

^*University of British Columbia, Anatomical Pathology, Vancouver, Canada

Background & Objective: SOX10 immunohistochemical (IHC) staining is used to identify tumours of neural crest origin, including melanocytic neoplasms and has been identified in myoepithelial cells of the breast and in a subset of invasive mammary carcinomas. The aim of this study was to characterize the SOX10 IHC staining in invasive ductal carcinomas according to molecular subtype, as well as in benign breast tissue.

Method: Forty cases of invasive ductal carcinoma of the breast were retrieved. Ten cases of each of the following molecular subgroups were selected: luminal A, luminal B, HER2-enriched, and triple negative subtypes. Whole tissue sections from each case were stained with mouse monoclonal antibody against SOX10. SOX10 staining was assessed within the invasive carcinoma, and when available, DCIS and benign breast tissue.

Results: Six (60%) of 10 triple-negative tumours were SOX10+ compared to 1 (3%) of 30 carcinomas of other molecular subtypes (p = 0.0003). All but one of the positive tumours showed at least moderate expression in at least 40% of tumour cells. All 7 cases SOX10+ carcinomas were grade 3 tumours (p = 0.01). Of the 13 cases with DCIS available for assessment, 1 (8%) showed positive SOX10 expression. All 22 cases with normal breast tissues available for assessment showed patchy SOX10 expression in both myoepithelial and luminal cells. SOX10 showed incomplete myoepithelial staining compared to other myoepithelial markers.

Conclusion: The triple-negative subtype of invasive ductal carcinomas shows a high rate of SOX10-positivity. SOX10 IHC cannot reliably differentiate between high-grade triple negative carcinomas, melanomas, and myoepithelial tumours in the breast.

OFP-09-010

Comparative analysis of human epidermal growth factor receptor 2 (HER2) testing in breast cancer according to 2007 and 2013 American Society of Clinical Oncology / College of American Pathologist guideline recommendations (ASCO/CAP)

A. Wernicke^*, P. De la Iglesia, H. Garcia Rivello

^*Hospital Italiano de Buenos Aires, Anatomia Patologica, Argentina

Background & Objective: Accurate determination of HER2 status is critical for optimal treatment of breast cancer. Our objetive was to study the effect of the 2013 updates to the 2007 ASCO/CAP recommendations for HER2 testing in breast cancer.

Method: Patient cases with HER2 studies were selected during two 12-month periods (2012 and 2015). The number of tests performed, type of specimen, proportion of HER2-positive and equivocal cases, and number of repeat tests on subsequent excisional specimens were examined and compared.

Results: Although the number of samples tested increased between 2012 and 2015 (378 v 540) , HER2 positivity remained constant (14.1% v 14.8%). The number of repeat tests for immunohistochemistry (IHC) within 6 months increased (2% v 7%). Determination on percutaneous biopsies was also increased (46,8% v 80.42%). Tumours categorized as negative (0 - 1+) on IHC decreased from 72% to 68 %. Tumours categorized as equivocal (2+) increased (14,8% v 29,7%).

Conclusion: Our findings indicate that the 2013 updates guidelines did not affect the overall HER2-positivity rate. The proportion of tests and repeat tests performed increased, as did the number of patient cases categorized as HER2 IHC equivocal (2+). There is a shift towards the use of core biopsy for HER2 testing.

OFP-09-011

Doxycycline pre-operatively in early breast cancer

C. Scatena^*, M. Ghilli, P. Aretini, M. Menicagli, G. Fanelli, C. Marini, A. Di Paolo, C. M. Mazzanti, M. Roncella, F. Sotgia, M. P. Lisanti, A. G. Naccarato

^*University of Pisa, Dept. of Translational Research, New Surgical and Med. Technologies, Italy

Background & Objective: Cancer stem cells (CSCs) have been implicated in disease recurrence, metastatic spread and poor patient survival in multiple tumours, breast cancer (BC) included. CSCs selectively overexpress key mitochondrial-related proteins and inhibition of mitochondrial function may represent a new potential approach for the eradication of CSCs. Because mitochondria evolved from bacteria, many classes of FDA-approved antibiotics, including doxycycline, actually target mitochondria. Our study aimed to determine whether short-term pre-operative treatment with oral doxycycline results in reduction of CSCs in early BC patients.

Method: Doxycycline was administered orally for 14 days before surgery for a daily dose of 200 mg. Immunohistochemical analysis on formalin-fixed paraffin-embedded samples from 15 patients, of which 9 were treated with doxycycline and 6 controls (no treatment), was performed with known biomarkers of stemness (CD44, CD24, ALDH1), mitochondrial mass (TOMM20), cell proliferation (ki67, p27), apoptosis (cleaved caspase-3) and neoangiogenesis (CD31). For each patient, the analysis was performed both on pre-operative specimens (core-biopsies) and surgical specimens. Changes from baseline to post-treatment were assessed with MedCalc 12 (unpaired T-test).

Results: Post-doxycycline tumour samples demonstrated a statistically significant decrease in the stemness marker CD44 (p-value < 0.005), when compared to pre-doxycycline samples. In contrast, markers of mitochodrial mass, proliferation, apoptosis and neoangiogenesis were similar between the two groups.

Conclusion: The decrease of CD44 expression is consistent with pre-clinical experiments and suggests that doxycycline can selectively eradicate CSCs in BC patients in vivo. Future studies (with larger numbers of patients) will be conducted to validate these promising pilot studies.

OFP-09-012

Tumour infiltrating lymphocytes (TILs) among multiregional metastases in metastatic breast cancers

L. S. Silva Alcoser^*, S. Gonçalves-Ribeiro, A. Aula, M. Giner, G. Villacampa, E. Martínez, N. Ciriaco, R. Dienstmann, S. Ramón y Cajal, V. Peg, L. De Mattos-Arruda

^*Hospital Vall d'Hebron, Pathology, Barcelona, Spain

Background & Objective: Tumour heterogeneity affects the progression of breast cancer. TILs have been studied in primary tumours, but few is known about their patterns in metastases. Our objective has been to study the tumour immune microenvironment in multiple organs affected by breast cancer.

Method: We included 10 patients with breast cancer in whom a clinical autopsy was performed. Their primary tumours(N=3) and multiple metastatic foci(N=99) were collected. The immunohistochemical expression of 5 markers (MA) was evaluated: CD3, CD4, CD8, CD45RO, FOXP3. The Kruskal-Wallis test (ANOVA) and the method of comparison by pairs were used through the Dunn test.

Results: The levels of the MA were evaluated in brain, liver, lung, ovary and other organs and in 3 primary tumours. Marker variation was seen by affected organ for metastasis of CD8, CD3, CD4, CD45RO (p<0.05), but not for FOXP3 (p=0.68). In organ comparisons, lung samples had a higher expression of several MA than brain samples (CD8, CD3 and CD45R0, p<0.05). In the intra-patient evaluation it was possible to observe differentiated patterns of the TILs according to the location of the neoplastic cells (more in lung vs other organs). Differences were seen in the expression of CD45RO between ER+/HER2- and ER+/HER2+. Patients with ER+/HER2- presented higher values of CD45RO compared to the ER+/HER2 + patient group(p=0.008).

Conclusion: The tumour immune microenvironment within the same patient and in different organs is heterogeneous. This finding could explain why multiple metastases escape differently from the host immune system.

OFP-09-013

Internal radiation exposure from radioactive seeds for pathology staff, an unexplored aspect?

S. Rijnsdorp^*, B. Arends, G.-J. Streefland, Y. van Riet, I. van Lijnschoten

^*Catharina Hospital, Medical Physics, Eindhoven, The Netherlands

Background & Objective: Localization of breast lesions using seeds containing radioactive iodine-125 is performed for almost 20 years. Iodine-125 is encapsulated in a titanium shell, eliminating the possibility of internal radiation exposure. Literature demonstrates that the titanium shell remains intact during surgical resection. However, in the pathology laboratory occasionally a seed is damaged. Hypothetically, processing weakens the shell. Ingestion of iodine-125 from one seed may cause a radiation dose over 100 times annual exposure limits. In our experience, radiation safety concerning iodine-125 in pathology laboratories requires more attention. This study aimed at investigating the effect of processing steps in the pathology laboratory and embedment in human tissue and minimizing staff radiation risks through process optimization.

Method: Used and new seeds were exposed to the regular processes of cutting up surgical specimens, processing to paraffin blocks and sectioning of tissue blocks. Effects on the seeds were investigated by energy-dispersive X-ray spectroscopy. Staff radiation exposure and possible procedural improvements were assessed in each step.

Results: Neither exposure to chemicals applied nor embedment in tissue altered the thickness or composition of titanium. Improvements to the process included accurate accounting for radioactive seeds, individual storage of seeds and improved documentation for tissue supplied by the surgeon. After optimizing the protocol, no additional radiation incidents were observed. Awareness of radiation safety among staff increased.

Conclusion: Iodine-125 seeds are not fully resistant to mechanical handling in the pathology laboratory. Optimizing procedures reduces the chances of dissecting radioactive seeds and improves radiation safety in the pathology laboratory.

OFP-09-014

“Oncomining” breast: findings of NGS analysis in carcinomas and applicability in needle biopsies

G. Frigola^*, B. Gonzalez-Farré, E. Fernández, A. Nadal, P. Jares, P. L. Fernández

^*Hospital Clínic, Pathology Dept., Barcelona, Spain

Background & Objective: With the implementation of NGS-based techniques in routine diagnostics, tumours are currently not only classified on the basis of their histology, but also on their profile of genomic alterations. In this context, targeted-gene sequencing can be of great value to offer the best possible treatment. We report our experience with Oncomine Solid Tumour DNA Kit®, a test covering hotspots of 22 frequent mutated genes in cancer, in a small cohort of invasive breast carcinoma, mostly in small needle biopsies

Method: Oncomine Solid Tumour DNA Kit® was performed in the PGM platform in 34 formalin-fixed paraffin-embedded tissue samples of invasive breast carcinoma (14 estrogen receptor positive [ER+], 16 triple negative [TN], 1 HER2-enriched, 2 unclassified). Relevant clinical and pathological information was collected for each case. Mutation status was examined with respect to clinical, pathologic, and immunohistochemical parameters.

Results: TP53 was the most prevalent mutated gene (33%), followed by PIK3CA (24%). Non-luminal (TN, Her2-enriched) cases displayed significantly more mutations per case than ER+ cases (p=0,0384). Mutations in TP53 as well as in receptors tyrosin kinase EGFR and MET were significantly associated with TN subtype (p=0,0084; p=0,0068). Interestingly, the 4 cases with MET mutations had coincidental mutations in TP53. A luminal B case immunohistochemically negative for Her2 showed an activating actionable mutation in ERBB2 by NGS that was used for treatment.

Conclusion: NGS analysis with the Oncomine test is feasible in breast needle biopsies and has the potential for detecting relevant genetic events for patient management by offering personalized therapeutic options.

OFP-09-015

Papillary breast lesions: concordance study between core needle biopsy and surgical specimen diagnosis. Are we overtreating patients?

A. Marques^*, I. Gullo, I. Amendoeira

^*Centro Hospitalar de São João, Pathology, Porto, Portugal

Background & Objective: Papillary breast lesions represent a heterogeneous group with similar morphological characteristics but distinct biological behavior. The categorization of papillary lesions remains one of the most challenging topics in breast pathology. Aim: to determine the concordance rate between core needle biopsy (CNB) and surgical specimen diagnoses of papillary breast lesions in a nineteen-year period (2000-2018).

Method: Papillary lesions diagnosed in CNB (n=152) and respective surgical specimens, when available, were retrieved from our Pathology Department database and reviewed.

Results: Papillary lesions in CNBs were classified as: B2-benign (n=63;41,4%), B3-uncertain malignant potential (n=67;44,1%) and B5-malignant (n=22;14.5%). In B2 group, 18/63(28.6%) lesions were excised and diagnosed as: papillomas (n=17;94.4%); papilloma with DCIS (n=1; 5.6%). In B5 group, all excised lesions were classified as malignant: papillary DCIS (n=8); encapsulated papillary carcinoma (n=6); solid papillary carcinoma (n=3); mixed invasive carcinoma (n=2); NST carcinoma with solid papillary areas (n=2); papillary carcinoma (n=1). In B3 group, 58/67(86.6%) lesions were excised, and 40 (69%) were classified as benign: papilloma (n=32); papilloma with atypical hyperplasia (n=7); complex sclerosing lesion (n=1). The remaining B3 lesions 18/58(31%) were classified as malignant: papillary DCIS (n=10); encapsulated papillary carcinoma (n=6); solid papillary carcinoma (n=1); mixed invasive carcinoma (n=1). Size tended to be smaller in benign compared to malignant lesions (median diameter:16mm and 34.5mm, respectively).

Conclusion: The concordance rate between the diagnoses in CNB and surgical specimens is high in benign and malignant lesions (94.4% and 100%, respectively). The high rate of benign lesions in the B3 group (69%) raises the possibility of overtreatment in some cases and should be taken into consideration whenever discussing treatment options.

Tuesday, 11 September 2018, 08:30 - 12:00, Room B1

OFP-10 | Gynaecological Pathology

OFP-10-001

Genotype and phenotype of POLE mutated endometrial cancer

T. T. Rau^*, D. Nastic, M. Ghaderi, S. Imboden, M. D. Mueller, E. Epstein, J. W. Carlson

^*Institute of Pathology, University Bern, Switzerland

Background & Objective: Since the TCGA publication in 2013 endometrial carcinoma with POLE mutations are of interest as they are typically ultra-mutated and highly immunogenic. Previous studies with limited patient numbers additionally showed an excellent outcome. The aim of our study was to substantially increase the number of POLE mutated tumours and to correlate it with clinicopathologic parameters and outcome.

Method: The cohort was combined from the University Hospital of Bern, Switzerland (N=255) and the Karolinska Institute, Sweden (N= 349). Clinical data include preoperative patient characteristics, therapies, histology, and follow-up. To identify POLE exonuclease domain mutations, genomic DNA was isolated from FFPE tumour tissue and transferred to standard Sanger Sequencing of the exons 9-14.

Results: Pathogenic POLE mutations were identified in 54 of 599 analyzable tumours (9%). The mutations were located on exons 9,12,13, and 14. POLE mutated tumours occurred at younger age (61.3 yrs vs 66.6 yrs; p=0.001), showed more lymphovascular space invasion (LVSI) and more aneuploid tumours. Clinically, no significances were found for BMI, family history of cancer or medication. Histologically, no differences in FIGO stage, tumour type or grade were evident. POLE mutated tumours showed a slightly better progression free and disease specific survival, however these differences were not significant (log rank p= 0.322 and p= 0.988).

Conclusion: Our findings indicate that the role of POLE mutations in the prognosis of endometrial cancer still needs more clarification. Possibly more factors such as additional mutations or total mutational burden might be needed to define the differences of prognostication in POLE mutated endometrial carcinoma.

OFP-10-002

Time series analysis of TP53 gene mutations in recurrent vulvar cancer

K. Kashofer^*, E. Winter, O. Reich, G. Hoefler, S. Regauer

^*Institute of Pathology, Med. Univ. Graz, Austria

Background & Objective: The impact of TP53 gene mutations in the clinical course of vulvar squamous cell carcinomas (SCC) is unclear. In is unknown which role TP53 gene mutations play for recurrent vulvar SCC and if the TP53 gene mutational status influences disease-free intervals.

Method: To document the course of TP53 mutations in recurrent HPV-negative SCC arising in inflammatory vulvar dermatoses the full coding sequence of the TP53 gene was analyzed in DNA extracted from archival tissues of primary and recurrent SCC of 21 women and correlated with disease-free survival.

Results: 6/21 patients with a p53 wild-type SCC had the first recurrence after a median of 62 months (range 14-144). 3 SCC recurred as p53 wild-type and 3 harbored TP53 mutations. 15/21 primary SCC with TP53 mutations recurred after 42 months (range 12-108). The primary SCC harbored TP53 point mutations (n=10), frame shift (n=4) and stopgain mutations (n=1). 13/15 recurrent SCCs carried again TP53 mutations: 5 with identical mutations, 8 with different, more complex TP53 mutations. The p53 mutational status in the recurrence changed in 5/21 patients after 5-7 years disease-free intervals. Patients with multiple recurrences had increasingly shorter disease-free intervals with identical TP53 mutations.

Conclusion: In summary SCCs with and without TP53 mutations recurred, but patients with p53 wild-type SCCs had longer disease-free intervals. TP53 mutations showed higher complexity in recurrences indicating increased genetic instability. True clonal recurrences with identical mutations were rare. These observations suggest that TP53 mutational status may affect oncological outcome in HPV-vulvar SCC and may assist in therapy planning and as a prognostic marker.

OFP-10-003

P16 immunostaining and HPV detection are reliable tools to differentiate squamous cell carcinoma of the cervix metastatic to the lung and primary pulmonary squamous cell carcinoma

S. Petronilho^*, A. Tavares, A. Nogueira, R. Vieira, A. L. Cunha, H. Sousa, M. Ferreira, R. Henrique, R. Medeiros, C. Bartosch

^*IPO-Porto, Pathology, Portugal

Background & Objective: Squamous cell carcinoma (SCC) of the cervix is virtually always associated with persistent high-risk human papillomavirus (HR-HPV) infection. When women with primary cervical SCC develop squamous lung lesions, distinguishing a metastatic lesion from a second primary is challenging. We aimed to assess the usefulness of p16 and HPV in the differential diagnosis between primary pulmonary SCC and metastatic lung SCC originating from the cervix.

Method: We retrospectively reviewed a cohort of primary pulmonary SCCs (n=22), lung metastases from cervix SCC (n=25) and paired cervical primaries (n=14) diagnosed at IPO-Porto (1986–2018). P16 immunostaining and HPV genotyping were performed. Statistical analysis was done to compare groups.

Results: P16 was diffusely positive(block-like) in 21 metastases and one primary pulmonary SCC (84%vs.5%, p<0.001); multifocal in two metastases and six primaries (8%vs.27%) and negative in two metastases and 15 primaries (8%vs.68%). HPV DNA was detected in 14 lung metastases and in none of primary pulmonary SCCs (67%vs.0%, p<0.001). In 7 metastases HPV testing was inconclusive due to poor/insufficient material. Sensitivity/specificity were: 84%(CI:64-96)/96%(CI:77-100) for p16 immunohistochemistry (positivity threshold: block-like staining), 67%(CI:43-85)/100%(CI:84-100) for HPV detection and 88%(CI:69-98)/96%(CI:77-100) for combined p16/HPV. Most HPV-positive tumours displayed p16 block-like positivity (13/14, 93%). HPV genotypes identified in metastases included HPV16 (57%), HPV18 (14%), HPV39 (14%), HPV59 (7%) and concomitant HPV18/HPV31 (7%). Metastases and corresponding primary cervical SCCs were concordant both for p16 (n=14) immunostaining and HR-HPV (n=5).

Conclusion: P16 and HPV testing are sensitive and specific markers to differentiate primary pulmonary SCC from metastatic SCC originating from the cervix and should be considered for routine diagnosis.

OFP-10-004

Should we continue to report cytopathic effects of HPV infection without dysplasia in cervical biopsies?

C. Bartosch^*, M. Pires, A. Tavares, H. Sousa, R. Medeiros, R. Dias, P. Monteiro

^*IPO-Porto, Pathology, Portugal

Background & Objective: According to current terminology, lesions previously described as koilocytosis without atypia, condylomas and CIN1 should all be designated as LSILs. However, given the high false-positive rate of histology for prediction of HPV infection, many pathologists continue to descriptively report koilocytosis per se. We aimed to determine the diagnostic frequency of koilocytosis without dysplasia in our current practice and review the clinicopathological features of these patients.

Method: We retrospectively reviewed all cervical biopsy reports from 2012 to 2017 (IPO-Porto, n=951), and identified those reporting koilocytosis without dysplasia. Patients’ clinical files were reviewed to retrieve HPV testing and previous cytology results, colposcopic findings, treatment and follow-up.

Results: We identified 93(10%) reports consistent with koilocytosis without dysplasia, corresponding to 82 patients. Mean patient age was 41y(range:21-75), four were under 25y. Globally, 69% cases were positive for high-risk HPV, but considering only patients without previous HPV testing, this decreases to 43%. Cytology results included: 25(31%) NILM, 25(31%) ASC-US, 23(29%) LSIL, 6(8%) ASC-H, 1(1%) HSIL. Colposcopy identified transformation zone not fully visible in 39% of patients and abnormal (minor/major) findings in 64%. Thirteen patients (16%) were submitted to cone biopsy, due to persistent LSIL(n=3), cytohistological discrepancy(n=3), progression to HSIL(n=2) and inadequate colposcopy(n=6).

Conclusion: Reporting histologic changes consistent with HPV instead of LSIL, reflects the expected level of uncertainty due to difficulties in distinguishing them from normal or reactive changes. Previous knowledge of HPV testing results seems to influence pathology reporting. Overdiagnosis of HPV changes in cervical biopsies may result in increased health care costs and unnecessary surgical procedures.

OFP-10-005

Systematic histology review of 1318 cases of gestational trophoblastic disease (GTD) referred to a tertiary referral centre in one-year period (2011)

P. Anketell^*, B. Kaur

^*Imperial College Healthcare NH, London, United Kingdom

Background & Objective: In the UK, clinical care for patients with GTD has been centralized since 1973. There are 3 centres for central review of these cases providing specialist care and centralised review of all cases with HM. This study was designed to look at the diagnostic pattern of cases referred with diagnosis of Hydatiform moles (HM) and gestational trophoblastic neoplasm (GTN) to Charing Cross Hospital, London in year 2011 and the role of referent pathologist in refining the diagnosis.

Method: All the cases of GTD referred from 1st January to 31st December 2011 were retrieved from our electronic data base. The diagnosis imparted on systematic review by one of the two specialist pathologists was compared to the referral diagnosis.

Results: A total of 1269 cases were referred with diagnosis of HM in the uterine cavity. Review confirmed HM in 849 (66.9%) cases; 420 (33.1%) cases were overcalled as HM. 1 of the 9 cases referred as non- molar miscarriage turned out to be a partial hydatiform mole. Of the 11 tubal ectopics that were submitted as likely molar, none showed evidence of HM. Of 38 cases referred with a diagnosis of GTN, 16 were confirmed as gestational trophoblastic tumours, 11 were placental site nodules (PSN/ APSN) and 11 diagnosed as non-gestational tumours.

Conclusion: Nearly a third of cases were overcalled as HM. Common mimics included aneuploidy, placental mesenchymal dysplasia, Digynic triploid, hydropic abortion and early miscarriage. Tubal ectopics with exaggerated appearing trophoblast remains the most common pitfall.

OFP-10-006

Association of tumour morphology with mismatch-repair protein status in endometrial cancers: a single unit experience

D. D. Di Nanni^*, A. De Leo, C. Ceccarelli, A. M. Perrone, P. De Iaco, D. Santini

^*S. Orsola-Malpighi Hospital, Dept. of Pathology, Bologna, Italy

Background & Objective: The aim of the study was to analyze the clinicopathological characteristics of endometrial cancers (EC) focusing on those correlated with DNA mismatch repair (MMR) alterations.

Method: 106 cases of EC have been collected between 2015 and 2017. For each case we reported: histotype, tumour grade, isthmus involvement, pattern of invasion, tumour-infiltrating lymphocytes (TILs), lymphovascular invasion (LVI), myometrial invasion, lymph node metastases, endometriosis, tubaric lesions. Immunohistochemical evaluation of the MMR proteins (hMLH1, hPMS2, hMSH2, hMSH6) and microsatellite instability (MSI) analysis were performed.

Results: 23/106 (21%) cases showed immunohistochemical alteration of MMR proteins: 7 (33.3%) cases lost hMLH1 with MLH1 promoter hypermethylation, 16 (66.7%) EC had a loss of hMSH2 and/or hMSH6 and 13 (81.2%) of these had a familiar neoplastic history. 11 (68%) MSH2-MSH6 deficient EC were endometrioid, 4 (25%) showed prominent ambiguous features and 1 was a serous carcinoma. MELF pattern of myoinvasion was identified in 9 cases. TILs was >40/10HPF in 5 cases. 2 cases of tubaric lesions (1 case of STIC - Serous Tubal Intraepithelial Carcinoma -, 1 case of SCOUT - Secretory Cell Outgrowth -) were found. 5 (21.7%) EC cases had lymph node metastases (all with diffuse LVI and 4 (80%) with MELF). A statistically significant association between loss of MMR-IHC and EC with ambiguous features and/or MELF pattern of invasion was found (p<0.05).

Conclusion: The MMR-deficient EC showed more frequent ambiguous features, TILs and MELF pattern of myoinvasion. Morphological features along with IHC-MMR enhance the detection of EC patients at risk of Lynch syndrome.

OFP-10-007

Hedgehog pathway expression in high grade serous carcinoma of the ovary and clinical implications

R. Ganesan^*, R. Pounds, C. Dawson, S. Kehoe, J. Yap

^*Birmingham Women´s Hospital, Cellular Pathology, United Kingdom

Background & Objective: Ovarian cancer is the fifth leading cause of death from cancer among women. A pathway of interest is Hedgehog (HH) signalling pathway, whose aberrant activation has been reported in ovarian cancer. We determined the prevalence of HH pathway activation in high-grade serous ovarian cancer (HGSOvCa) by immunohistochemistry and in cell lines.

Method: Formalin-fixed paraffin embedded blocks were obtained for a cohort of 56 patients and immunohistochemical staining performed for HH pathway components GLI1, PTCH1 and SHH. Expression of the HH pathway components was correlated to clinical outcomes. Ovarian cancer cell lines were tested.

Results: All cases had a high or moderate expression of GLi1 and greater than 90% of patients had either high or moderate expression of PTCH and SHH. Patients with high expression of HH pathway components had more disease recurrence. The risk of disease recurrence was significantly increased in those with high SHH expression (p = 0.0121). Patients with high SHH ligand expression in their primary tumour had significantly reduced 5-year survival. Western blotting analysis demonstrated an increase in GLI1 and SHH protein expression in six ovarian cancer cell lines compared to the immortalised normal ovarian epithelial cell strain, OCE-1 indicating aberrant HH activation. Expression of both HH pathway components was decreased following treatment with HH inhibitors.

Conclusion: *Hedgehog pathway is aberrantly activated in HGSOvCa and over expression of HH components increases the risk of disease recurrence *Over-expression of SHH ligand is associated with a poor survival outcome following primary treatment *Hedgehog pathway components are overexpressed in ovarian cancer cell lines and are downregulated with Hedgehog inhibitors.

OFP-10-008

BCOR rearranged endometrial stromal sarcoma (ESS). A clinicopathological study of four cases

S. Renne^*, P. Collini, G. P. Dagrada, A. Gronchi, S. Radaelli, R. Sanfilippo, D. Lorusso, F. Raspagliesi, B. Paolini

^*Istituto Nazionale Tumouri, Dept. of Diagnostic Pathology, Milan, Italy

Background & Objective: A new translocation involving BCOR have been recently described in ESS. The literature covering this entity mainly consisted so far in small case series focused on molecular genetics and pathology. There is therefore a needing for a more precise clinical and pathological description of this entity to allow a more precise approach to patients. The aim of this study is to provide a detailed clinico-pathological description of BCOR rearranged ESS (BRESS).

Method: This study was approved by Institutional Ethics Committee. All the BRESS diagnosed at Fondazione IRCCS Istituto Nazionale dei Tumouri, Milan, Italy were included. All slides were reviewed; morphology, immunohistochemistry, AJCC Staging Group, treatment and follow-up were evaluated and recorded.

Results: Four patients full-filled the inclusion criteria (median age, 43 y). Most cases (3/4) presented with advanced stages. Surgical approach was hysteroannessectomy in all cases. Tongue like projections, lymphovascular involvement, spindle cell fascicular appearance and cytological atypia were demonstrated in all specimens. Collagen plaques were found in 3/4 cases, a myxoid microcystic pattern was found in half of the cases. All cases were strongly positive for BCL1 and CD10. Smooth muscle antigens, oestrogen and progesterone receptors were mostly negative. All patients underwent neoadjuvant or adjuvant Epirubicin + Ifosfamide. Case #1 did Gemcitabine + Docetaxel at progression. The final follow-up ranged from 7 to 13 months (median Follow-up, 9 mo). Two patients were with No Evidence of Disease after multimodal therapy. The remaining two patients are Alive With Disease.

Conclusion: BRESS is an aggressive disease presenting at advanced stage, managed with multimodal therapy.

OFP-10-009

Primary neuroectodermal tumours of the ovary: a clinico-pathologic study of 10 cases

A. Moscardó Navarro^*, I. Alvarado-Cabrero

^*Hospital Clínico Universitario, Anatomia Patológica, Valencia, Spain

Background & Objective: Primary Neuroectodermal Tumours (PNETs) of the ovary are rare monophasic teratomas composed exclusively or almost exclusively of neuroectodermal tissue. Approximately 100 cases of ovarian PNETs have been reported in the literature. The aim of this study was to investigate the morphologic features, clinical manifestations and prognosis of 10 cases of PNETs of the ovary.

Method: 10 ovarian PNETs diagnosed between 2000 and 2017 were collected from the surgical pathology files of the Hospital de Oncología, CMN SXXI IMSS.

Results: Patients ages ranged from 14 to 46 years (median, 28 years). The main clinical manifestations were irregular vaginal bleeding (5 patients), pelvic mass (8 patients), and lower abdominal pain (7 patients). The CA-125 levels of 5 patients were elevated. Eleven patients underwent surgical resection, and four patients underwent preoperative and/or postoperative combination chemotherapy. The tumours, which varied from cystic to solid, range from 8 to 24 cm (average, 15 cm) in diameter. Morphologic features of central nervous system tumours were seen: 5 ependymomas, 4 medulloblastomas, and one glioblastoma. By immunohistochemistry all cases expressed at least one marker of neuronal differentiation (synaptophysin, CD56, and chromogranin, GFAP was positive in 6 cases). The follow-up of all patients was available and ranged from 8 to 128 months. Six patients died of disease, 3 experienced recurrences and one is alive with disease.

Conclusion: PNETs of the ovary are rare monophasic teratomas, they mainly involve young women during their reproductive age, therefore, accurate diagnosis followed by multimodal treatment should be taken into consideration for fertility preservation.

OFP-10-010

Napsin and AMACR are superior to HNF1B in distinguishing between mesonephric carcinoma and clear cell carcinomas of the gynaecologic tract

J. Pors^*, A. Cheng, B. Gilks, L. N. Hoang

^*Vancouver General Hospital, Dept. of Anatomical Pathology, Canada

Background & Objective: Mesonephric carcinoma is a rare, non-HPV associated, gynaecologic neoplasm commonly mistaken for clear cell carcinoma. Both mesonephric carcinomas and clear cell carcinomas are negative for estrogen receptor (ER) and p16. HNF1B, a marker for clear cell carcinoma, has also been found to also be positive in a subset of mesonephric carcinomas. However, other more recent markers for clear cell carcinoma, such as Napsin and AMACR, have not yet been studied in mesonephric carcinomas.

Method: We assessed the immunohistochemical expression of HNF1B, Napsin, AMACR and ER in a series of 13 mesonephric carcinomas (5 uterine corpus, 5 cervical, 1 ovarian, 1 broad ligament, 1 vaginal; on whole sections) and 55 clear cell carcinomas (5 cervical, 50 uterine; on tissue microarrays). Any intensity staining in >1% of cells was considered positive.

Results: HNF1B expression was seen in 3/9 (33%) of mesonephric carcinomas and 50/55 (91%) of clear cell carcinomas. ER expression was seen in 3/13 (23%) mesonephric carcinomas and 6/55 (11%) clear cell carcinomas. Napsin expression was seen in 2/11 (18%) of mesonephric carcinomas, which was focal and present in only 1% of cells in both cases. Napsin expression was seen in 42/55 (76%) of clear cell carcinomas, which was more likely to be diffuse (average: 50% of cells). AMACR expression was seen in 1/11 (9%) of mesonephric carcinomas, which was again present in only 1% of cells.

Conclusion: Napsin and AMACR appear to be superior to HNF1B in distinguishing between mesonephric carcinomas and clear cell carcinomas of the female genital tract.

OFP-10-011

Transformation of ovarian low-grade serous carcinoma to high-grade carcinoma: a rare phenomenon and report of 4 cases

E. Cai^*, A. S. Cheng, B. Gilks, L. N. Hoang

^*University of British Columbia, Anatomical Pathology, Vancouver, Canada

Background & Objective: The transformation of ovarian low-grade serous carcinoma (LGSC) to high-grade carcinoma is exceedingly rare (with only 6 cases in the literature) and the molecular events behind the transformation are unknown. Our objective was to evaluate p53, BRAF and WT1 immunohistochemistry in 4 cases of LGSC with high-grade transformation, in order to better understand the underlying molecular events.

Method: We identified 4 cases where LGSC showed high-grade transformation. H&E slides were reviewed and immunohistochemistry was performed. p53 was scored as wild-type, null or overexpressed. BRAF and WT1 were scored as positive or negative.

Results: Two cases with a high-grade carcinoma arising from LGSC, showed positive WT1 and negative BRAF in both the low-grade and high-grade components. p53 was wildtype in the low-grade area of both cases. In the high-grade area of case 1, p53 was wild-type and in case 2, p53 was null. In case 3, the LGSC component was p53 wildtype but the transformed carcinosarcomatous component was p53 overexpressed. Again, BRAF was negative and WT1 was positive in both components. In case 4, LGSC transformed to an undifferentiated carcinoma (immunohistochemical stains were not available).

Conclusion: Transformation from LGSC to high grade carcinoma is rare, with only 4 cases occurring over 20 years at our institution. Acquisition of abnormal p53 was observed in 2 of 3 cases. No cases displayed abnormal BRAF. Targeted DNA sequencing is being performed with results to follow.

OFP-10-012

Evaluation of mismatch repair (MMR) protein expression with correlation of germline mutation analysis for Lynch syndrome screening in endometrial cancers in Turkish women; preliminary results

I. Erbarut Seven^*, F. E. Kombak, E. Bozkurtlar, C. Yalcinkaya, E. Arslan Ates, A. I. Güney, H. Gökaslan, F. Eren

^*Marmara University, Pathology, Istanbul, Turkey

Background & Objective: Universal screening for Lynch syndrome has been recommended for all endometrial carcinoma cases. Our aim is to investigate the incidence of MMR protein expression loss in a series of endometrial carcinomas; which can reflect Lynch syndrome (LS).

Method: We performed MLH1, MSH2, MSH6 and PMS2 immunohistochemistry (IHC) in 227 endometrial tumours operated between 2008-2018 followed by MLH-1 methylation testing when appropriate. MMR deficient cases were further sent to genetic analysis.

Results: 40 out of 227 (17.6%) cases displayed MLH1&PMS2 loss, 9 (3.9%) MSH2&MSH6 loss, 1 (0.4%) MSH6 loss and 5 (2.2%) PMS2 loss. 6 (15%) of MLH1 deficient cases were unmethylated. Overall a total of 21 (9.5%) cases were unmethylated MMR deficient and directed to genetic testing. 36.1% of these cases were nonendometrioid tumours. 3 patients had a history of colon cancer, synchronous colon cancer and synchronous ovarian cancer respectively. Concomitance and history of other cancers were associated with MMR deficient status (p=0.0001). Germline testing was performed in 5 cases until now and in 80% (n:4) Lynch syndrome was confirmed.

Conclusion: In our study, MMR immunohistochemistry and MLH1 methylation analysis together seems to be efficient for selecting patients to direct genetic surveillance and the preliminary results showed high correlation with germline testing. Therefore we suggest use of universal IHC screening for all endometrial carcinoma cases.

OFP-10-013

Does HPV16 status influence outcome in HPV positive cervical carcinomas?

A. Felix^*, S. Esteves, L. Martins, G. Esteves, L. Alemany, X. Bosch

^*Instituto Portugues Oncologia, Dept. of Pathology, Lisboa, Portugal

Background & Objective: HPV is an established cause of cervical cancer. In oral\\anogenital carcinomas HPV status possesses prognostic value, where HPV16 has a more favourable prognosis attributed to better treatment response. We compared HPV16 with other genotypes for disease-free survival (DFS) in HPV-associated cervical cancer.

Method: A retrospective cohort study evaluated 212 cervical carcinomas and analysed 159 cases after excluding HPV-negative carcinomas (n=20), multiple HPV infection (n=16), unknown HPV type (n=3) and persistent disease after initial treatment (n=14). LiPA25 was used for HPV-detection. Kaplan-Meier estimator and Cox regression were used.

Results: Median age was 50 years (range:26-87); 82% were squamous-cell carcinoma; FIGO stage was ≤IB1 in 37%, IB2-IIB2 in 40%, ≥III in 23%, unknown in 1%; 16% had lymph node metastases; 65% were HPV16-positive. Initial treatment comprised radiotherapy (RT, 64%) surgery (50%) and chemotherapy (9%). Median follow-up was 67 months. Overall 5-year DFS was 60% (65% in HPV16 and 49% in other genotypes group). HPV16 was associated with a significant 39% reduction in the hazard of relapse/death in univariate analysis (HR=0.61,95%CI0.38-0.98, p=0.04) and a non-significant 30% reduction when controlling for FIGO stage, lymph node metastasis and RT (adjusted HR=0.70, 95%CI 0.42-1.17, p=0.17). RT was independently associated with DFS (p=0.02) but without increased benefit in HPV16-driven cancers.

Conclusion: HPV16 was associated with an improvement of DFS although not significant when controlling for stage, lymph node metastasis and RT. We also found no evidence that HPV16 genotype predicts a better disease control in RT-treated patients.

OFP-10-014

BRCA and ovarian cancer: a morphological, immunohistochemical and genetic study of high grade serous carcinoma and tubal precursors

G. Santandrea^*, A. De Leo, C. Ceccarelli, G. Barbero, D. Turchetti, A. M. Perrone, P. De Iaco, D. Santini

^*Ospedale Sant´Orsola-Malpighi, Pathology, Bologna, Italy

Background & Objective: Solid-pseudoendometrioid-transitional (SET) variant of high grade serous carcinomas (HGSC) has been recently described in BRCA 1/2 mutated patients. The association between SET-HGSC and Serous tubal intraepithelial carcinoma (STIC) is still unclear. The aim of the study was to investigate the correlation between BRCA mutational status and HGSC morphology, tubal lesions, immunohistochemical (IHC) profile and tumour infiltrating lymphocytes (TILs).

Method: 27 consecutive patients with HGSC (patient mean age 52.5 years) were collected from 2015 to 2017. Tumour histological patterns were evaluated on H&E sections. HGSC diagnosis was confirmed by p53/WT1 IHC status, histological assessment of SCOUT (Secretory Cell Outgrowth), STIL (Serous Tubal Intraepithelial Lesion) and STIC was performed using a double Bcl2/p53 IHC staining. Intratumoural TILs (iTILs) were counted semi-quantitatively as reported in literature. BRCA mutational status was tested both on blood and tissue samples.

Results: 9 out of 27 (33.3%) patients carried a BRCA mutation, amongst them 7 (77.8%) were known pathological variants and 2 (22.2%) were variants of uncertain significance (VUS). SET morphology (≥50% solid-pseudoendometrioid-transitional) statistically tended towards BRCA+ patients compared to BRCA- group (p=0.06), while BRCA status became statistically irrelevant when VUS patients were excluded from BRCA mutated group. SET morphology resulted strongly associated with increased iTILs (p=0.0005). Furthermore, SET-HGSC showed a lower association with STIC compared to classic morphology (p=0.02).

Conclusion: SET-HGSC showed a statistically significant association with increased iTILs. STIC was significantly more frequent in HGSC with classic morphology. However, no histological features were significantly associated with BRCA mutational status in our series.

OFP-10-015

Human papillomavirus typing of cases showing atypical squamous cells of undetermined significance in pap tests in Israel

S. Aviel-Ronen^*, S. Tsabari, R. Shomrat, B. Czernobilsky, B. Lifschitz-Mercer

^*Patho-Lab Diagnostics Ltd., Dept. of Pathology, Shoham, Israel

Background & Objective: The types of HPV associated with development of uterine cervix dysplasia, carcinoma and genital warts are well characterized. Our aim was to study the distribution of HPV types in Israel among patients diagnosed as ASC-US in Pap test.

Method: HPV typing was performed in 209 cervical ThinPrep samples diagnosed as ASC-US using Master Diagnostics HPV Direct Flow CHIP on the eBRID automated system. This PCR amplification and reverse dot blot hybridization-based method identifies 36 types of HPV (18 high risk, 18 low risk) and the presence of unspecified HPV genotype (using a universal HPV probe detecting L1 consensus region).

Results: The median patient age in our cohort is 33 years (range 20-60 years, average 34.1 years). HPV typing showed no infection in 93 patients (44.5%), high risk HPV in 58 patients (27.8%), both high and low risk HPV in 17 patients (8.1%), low risk HPV in 27 patients (12.9%) and unspecified HPV in 13 patients (6.2%). In one case HPV typing failed. The relative prevalence we found for each of the 36 types is presented and shows differences from the traditional accepted distribution (e.g high prevalence of types 53, 66 and 42).

Conclusion: The relative prevalence of the HPV types we found in our cohort of ASC-US diagnosed patients deviates from the accepted distribution in the literature. The type of epithelial abnormality (LSIL & HSIL vs USC-US), method of HPV detection, geography as well as HPV vaccination may all contribute to these differences.

Tuesday, 11 September 2018, 17:15 - 19:15, Auditorium

OFP-11 | Cytopathology

OFP-11-001

Conisation rates in HPV-positive women after screening cotest with 2-3 year follow-up

A. Caminoa-Lizarralde^*, J. Duarte, J. M. Rodríguez-Barbero, J. A. Aramburu, I. Solís, P. Bajo, E. Camarmo, T. Corrales, R. Granados

^*Hosp. Universitario de Getafe, Pathology Dept., Spain

Background & Objective: Primary high-risk HPV (hr-HPV) screening yields a large number of positive tests needing follow-up (FU). For the sake of not missing high-grade lesions (CIN2+), we may be at risk for overtreatment. The aim of this study is to analyze the rate of cervical conization (CC) after a positive HPV test in a screening cotest study.

Method: Following positive HPV baseline results from a cotest screening of 5053 women, they were advised to undergo colposcopy. Depending on biopsy results, they were managed according to EU guidelines. Cytology was performed with ThinPrep® and HPV-mRNA detected by APTIMA®. CC of women with biopsy-proven CIN2+ lesions was issued. After a 2-3 year FU period, conization rate and histological review of samples was analyzed.

Results: The prevalence of hrHPV was 9% (454 cases), 299 samples with normal cytology and 155 with ASCUS+. A CIN2+ lesion was diagnosed in 90 of 272 (33,1%) hrHPV-positive women biopsied and was more common in women with HPV and cytology abnormalities (59,5% vs 21,3%). Conization was performed in 73 of them (26,8% of biopsied women) after FU, increasing from 22,2% (60/270) at baseline. Upon review, 6 cases were considered overtreated (2,2% of patients at FU) , reclassifying CIN2 biopsies.

Conclusion: CIN2+ lesions were treated by CC in 22,2% of hrHPV-positive women biopsied who underwent screening with cotest. This rate increase to 26,8% after 2-3 year FU. Histological overinterpretation of CIN lesions prompted conization in 2,2% of these patients. Caution to avoid overtreatment is advised after primary hrHPV testing.

OFP-11-002

Pitfalls in the diagnosis of anaplastic large cell lymphoma in cytology

U. Klopcic^*, G. Gasljevic

^*Institute of Oncology, Dept. of Cytopathology, Ljubljana, Slovenia

Background & Objective: Anaplastic large cell lymphoma (ALCL) is CD30 positive T-cell neoplasm which includes two morphologically indistinguishable subtypes ALK+ and ALK– ALCL. In fine needle aspiration biopsy (FNAB) samples it is sometimes difficult to differentiate between ALCL and other types of lymphomas with anaplastic features.

Method: We reviewed 48 cases that were initially diagnosed as ALCL or suspicious for ALCL from FNAB samples between 2008 and 2017.

Results: 26 out of 48 cases were confirmed as ALCL by histology, in 10 cases histological examination was either not performed or was inconclusive due to inadequate or necrotic samples and in eight cases different type of lymphoma was diagnosed: peripheral T-cell lymphoma NOS (PTCL NOS) in two, Hodgkin lymphoma (HL) in three cases and one case of diffuse large B-cell lymphoma (DLBCL), ALK-positive large B-cell lymphoma and angioimmunoblastic T-cell lymphoma (AITL). In cases of PTCL NOS and AITL cytological diagnosis was based on many anaplastic cells similar as present in other ALCL cases, which expressed CD30 and T-cell markers. In one case of HL we only had morphology, in two other cases CD15 was negative and T-cell markers were not performed. In DLBCL case anaplastic cells were CD30 positive and on flow cytometry we could not prove monoclonality of B cells. The case of ALK-positive large B-cell lymphoma was missed because of inadequate immunostains.

Conclusion: Most cases of ALCL could reliably be diagnosed from FNAB samples if material is adequate for additional immunocytochemical and flow cytometric studies. The main issue remains differentiation from other CD30 positive T-cell lymphomas with anaplastic morphology.

OFP-11-004

Cytomorphological and fluorescent immunocytochemical diagnosis of effusions from the abdominal cavity on biochips using telemedicine technologies

M. Savostikova^*, E. Furminskaya, E. Fedoseeva, A. Kudaybergenova, N. Nikolaeva, I. Kruglova, S. Zinoviev, O. Utkin

^*N.N. Blokhin RCRC, Cytology, Moscow, Russia

Background & Objective: The study is conducted to evaluate the possibilities and advantages of using fluorescent immunocytochemical techniques (FICC) of effluent liquids on biochips, and the possibility of remote result interpretation.

Method: 98 ascites fluids were studied cytologically and with FICC on biochips, including the further use of telemedicine technologies. Biochip is a high-tech medical product that is a glass preparation divided in cells and containing MA: Ber-Ep4, CA-125, SK7, CK20 conjugated with fluorochrome AlexaFluor488. The study included: traditional cytological study on liquid preparations, FICC biochip study, on-line consultation of biochip reaction images. Used equipment: Cytospin-3 cytocentrifuge, Bioscan001S scanner, Zeiss Axio imager Z2 fluorescence microscope. The control was made by the traditional ICС.

Results: 98 samples were cytologically examined: specific exudate was diagnosed in 41 cases, exudate with reactive changes in mesothelium – 23 cases, presumptive diagnosis of metastatic effusion - 34 cases. Subsequent FICC confirmed traditional cytology and supplemented the metastatic exudate group to 63 samples, and the reactive ones up to 35 samples. The reaction with the MA group in 90.5% of the samples allowed to localize the primary source. Time for a single biochip study is 60 minutes. Result comparability with the traditional ICC was 91%.

Conclusion: FICС study on the biochip is a reliable and fast method for diagnosing the nature of exudate fluids, which is comparable in accuracy with traditional ICC differential diagnosis of the tumour process. This biochip advantage is the availability at the medical institutions, where there is no full cytological laboratory.

OFP-11-005

Pancreatic endoscopic ultrasound-guided fine needle aspiration cytology: its importance in clinical practice over a period of 10 years

D. Argyropoulou^*, J. Nogueira, P. Pinto-Marques, M. Brito

^*Hospital Garcia de Orta, Anatomia Patologica, Almada, Portugal

Background & Objective: Pancreatic Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytology (EUS-FNAC) is a well-established, minimally invasive, safe and cost-effective diagnostic procedure, leading to accurate diagnoses. We aimed to analyze the importance of Pancreatic EUS-FNAC, in the diagnosis of pancreatic lesions at our institution, over a period of 10 years.

Method: All pathology reports and clinical data were retrieved from the files, over a period of 10 years. The EUS-FNA and Cytology protocols, as well as the percentage of non-diagnostic cytologies and the diagnoses, were analyzed.

Results: Over a period of 10 years, 653 Pancreatic EUS-FNAC were performed at our hospital by the same gastroenterologist using 19G, 22G or 25 G needles, in the presence of a cytotechnologist. Smears (an average of 3 Giemsa+ 3 Papanicolaou) and a cell-block (for Haematoxylin-Eosin stain, immunocytochemistry and molecular biology techniques), were performed. FNACs were read by 2 pathologists. There were 94.2% diagnostic cytologies. Forty-eight percent (48.4%) of the cytologies were positive for malignancy. 82.5% had a specific diagnosis of which the main groups were: adenocarcinoma (n=255), serous cysts (n= 66), neuroendocrine tumours (n= 44), mucinous tumours (n=40), and metastatic lesions (n=16). In the group of patients with a EUS-FNAC specific diagnosis, this was accepted as the final diagnosis for the management of patients by the Multidisciplinary Team Meeting with no further invasive diagnostic procedures.

Conclusion: At our institution, pancreatic EUS-FNAC has proven to have a high accuracy for the diagnosis of pancreatic lesions and be an important tool in the management of these patients.

OFP-11-006

False negative results in thyroid fine needle aspiration cytology

R. Veiga^*, E. Mendonça, A. Martins, A. Garrão, H. Marques, M. Olímpia Cid, F. Rosário, A. Catarino

^*Hospital da Luz Lisboa, Anatomic Pathology, Queijas, Portugal

Background & Objective: Thyroid fine needle aspiration (FNA) has a reported false negative rate (FN) lower than 3%. We aimed to estimate the FN of thyroid FNA in our institution and to understand its causes.

Method: Between 2012 and 2016, 8160 thyroid FNAs were performed, the vast majority (95%) with ultrasound (US) guidance. Of these, 4900 (60%) were diagnosed as benign, from which 659 were submitted to surgery. A histologic diagnosis of malignancy was made in 10 (1.5% FN). These cases were then reviewed.

Results: The patients (6 men, 4 women) were between 18-72 years old. Nodules ranged from 38-95 mm. The US risk of malignancy was re-appreciated in 7 patients (low in 6, intermediate in 1 - ATA 2015). The diagnosis of hyperplastic/colloid nodule was maintained in 8 cases and 2 were reclassified as follicular lesions of undetermined significance. Histologically, 7 cases were reclassified as NIFTP, and the remaining as follicular variant PTC (PTCFV). Macrofollicular/cystic areas, focal or diffuse, and a heterogeneous distribution of typical PTC nuclei were found in all tumours. Clinical follow-up was available for 7 patients (from 9-24 months). Only one did not remain free of disease; he developed lung and bone metastasis that regressed after radioactive iodine therapy.

Conclusion: The FN in our institution is according to the literature. All cases were nodules >35mm, diagnosed as NIFTP or PTCFV. The US risk of malignancy did not contribute to identify these cases. Macrofollicular/cystic areas rich in colloid and heterogeneous distribution of typical PTC nuclei are potential pitfalls for the occurrence of FN.

OFP-11-007

Evaluation of a biomarker panel for the diagnosis of cavity effusions

L. Antonangelo^*, C. Silvério Faria, M. M.P. Ascencio, D. Cristina Batista Rosolen, D. Doi, D. Kanaan Faria

^*University of Sao Paulo, Pathology, São Paulo, Brazil

Background & Objective: Laboratory investigation of cavity fluids involves the combined evaluation of biochemical, immunological, microbiological, molecular and cytological parameters. However, routine laboratory exams do not always clarify the etiology of an effusion, stimulating the research for new biomarkers for this purpose. This aim of this study was to evaluate the performance of a hybrid panel of biomarkers in the diagnosis of the main diseases affecting pleura and/or peritoneum.

Method: Peritoneal and pleural fluids samples from 120 patients were evaluated for: NGAL (neutrophil gelatinase), VEGF-A (vascular endothelial growth factor A), PD-L1/B7-H1 (death-binding pathway), CEA (carcinoembryonic antigen), TREM-1 (trigger receptor expressed in myeloid cells type 1) and IFNγ (gamma-interferon) by Luminex®; CALP (Calprotectin) by ELISA, and ADA (adenosine deaminase) by enzymatic deamination.

Results: For malignant effusion diagnosis, CEA and NGAL presented superior performance than VEGF-A, PD-L1 and CALP. A CEA-NGAL-VEGF-A association improved sensitivity (82.0%) and accuracy (79.2%). For parapneumonic pleural effusion (PPE) and bacterial peritonitis (SBP), NGAL presented the best performance with sensitivity (57.1%), specificity (84.7%), NPV (84.7%) and accuracy (80.0%), higher than TREM-1 and CALP. A NGAL-TREM-1 association improved sensitivity (75.0%). For the diagnosis of pleural tuberculosis, γINF and ADA presented excellent specificity and NPV (93.3% and 98%, respectively) and accuracies (~93%). ADA associated to γINF-ADA showed sensitivity of 100%.

Conclusion: ADA, γINF, NGAL, CEA and VEGF-A were useful in discriminating tuberculosis and malignant etiology. However, for PPE and SBP, the used panel did not demonstrate diagnostic advantages over classic parameters DHL, pH and glucose.

OFP-11-008

Performance of the UroVysion® FISH assay for the diagnosis of malignant effusions using two cutoff strategies

L. Antonangelo^*, D. Kanaan Faria, C. Faria, D. Cristina Batista Rosolen

^*University of Sao Paulo, Pathology, São Paulo, Brazil

Background & Objective: The cytological examination of cavity fluids has limited sensitivity in the diagnosis of malignancy. Aneuploidy, which is commonly observed in neoplastic cells, could potentially be used as an ancillary diagnostic tool. The aim of this study was to evaluate the detection of aneuploid cells in cavitary effusion samples using the fluorescence in situ hybridization (FISH) assay UroVysion® with some adaptations and two different cutoff strategies.

Method: Seventy samples of pleural or peritoneal fluid with positive (n=40), negative (n=15) or suspicious (n=15) oncotic cytology were subjected to FISH assay with the multitarget UroVysion® kit, which is composed of probes that hybridize to the centromeric region of chromosomes 3, 7 and 17 and to the locus 9p21. FISH performance was evaluated using two different cutoffs: 1) the manufacturer’s cutoff (M-FISH) and 2) a proposed cutoff (P-FISH).

Results: Using M-FISH, the diagnostic sensitivity was 57.1%, specificity 87.5% and accuracy 60.0%; with P-FISH, the sensitivity was 87.3%, specificity 71.4% and accuracy 85.7%. When combined to cytology, the sensitivity, specificity and accuracy were 88.0%, 83.3% and 87.8%, respectively. Malignant cells presented a predominance of chromosomal gains.

Conclusion: The UroVysion® test using the P-FISH cutoff was effective in demonstrating aneuploid cells in all malignant effusions, confirming the diagnosis of malignancy even in cases with suspicious cytology.

OFP-11-009

Insulinoma-associated protein 1 (INSM1) is a sensitive and specific marker for lung neuroendocrine tumours in cytologic and surgical specimens

K. Viswanathan^*, A. Borczuk, M. Siddiqui

^*Weill Cornell Medicine, Pathology and Lab Medicine, New York, USA

Background & Objective: Insulinoma-associated protein 1 (INSM1) is a potential immunohistochemical (IHC) marker for neuroendocrine differentiation with reported superior sensitivity and specificity. In this study, we performed INSM1 staining in cytology cell blocks (CB) and tested its performance in large cohorts, which has previously not been done.

Method: Small cell (SCLC, 10 cases) and large cell neuroendocrine carcinoma (LCNEC, 9 cases), typical and atypical carcinoid (12 and 11 cases), squamous cell carcinoma (SQ, 10 cases) and adenocarcinoma (ADCa, 12 cases) CB from 2007-2018 were retrieved along with 430 ADCa, 58 SQ, 17 large cell carcinoma (LCC), 24 non-small cell lung carcinoma (NSCLC ) surgical cases. INSM1 (SantaCruz Biotech.) IHC was graded as 1+, 2+ or 3+. For CB, 2+ and 3+ were considered positive, whereas for resections, 1+ and higher in >5% of cells was considered positive.

Results: Nuclear INSM1 was seen in carcinoids (typical 12/12 (100%) and atypical 11/11 (100%)), 8/10 (80%) SCLC and (7/9) 78% LCNEC in CB, but not in AdCa and SQ cases. In resections, INSM1 was seen in carcinoids (typical 17/18 (94.4%); atypical 14/15 (93.5%), 11/11 (100%) SCLC and 10/12 (83.3%) LCNEC. AdCa 6/424 (1.4%), SQ 1/58 (1.7%), LCC 3/17 (21.4%) and NSCLC 1/24 (4.4%) showed INSM1 expression. INSM1 sensitivity and specificity in cytology and surgical cases were 90.5% and 100%, and 92.9% and 97.9%, respectively.

Conclusion: This large cohort further establishes the high sensitivity and specificity of INSM1 in pulmonary neuroendocrine tumours, in both cytologic and surgical specimens, which outperforms existing neuroendocrine markers.

OFP-11-010

Comparison of SurePath and GluCyte LBC platforms in detecting CIN2+ among ASC-US cytology patients using biomarkers

R. Alaghehbandan^*, S. Ratnam

^*University of British Columbia, Pathology, Vancouver, Canada

Background & Objective: To assess and compare the predictability of ASC-US cytology by SurePath (BD) and CellSolutions LBC platforms in relations to MCM/Top2A (ProEx C, BD), HPV E6E7 mRNA (Proofer, NorChip) and HPV DNA (HC II, Qiagen) in identifying CIN2+.

Method: Study population consisted of patients referred for colposcopy in 5 of the 10 Canadian provinces as part of the TPAPT (Transient Persistent And Persistent Transforming) study. Cytology sample from each patient was collected in SurePath medium and processed per manufacturer's instructions and read. From the residual SurePath sample, a GluCyte slide was likewise processed and read. SurePath samples were tested for MCM/Top2A, HPV E6/E7 mRNA, and HPV DNA. Histology confirmed CIN2+ served as the disease end point. Binary logistic regression models were performed to examine the usefulness of biomarker profiles for each of the LBC platforms.

Results: 13.8% (251/1821) and 20.8% (69/331) patients were identified as having ASC-US cytology by SurePath and GluCyte platforms, respectively. The frequency of CIN 2+ in SurePath and GluCyte cohorts were 22.3% (56/251) and 17.4% (12/69). Logistic regression analysis showed no statistically significant difference between the odds ratio in each model between the two platforms.

Conclusion: Our findings show that combining biomarkers are useful in identifying high grade dysplasia in patients with ASC-US cytology. No statistically significant difference was found between the odds ratio in each model between the two LBC platforms.

OFP-11-011

Causes of discordance between cytology and histology in pancreatic lesions

M. Elshiekh^*, R. Dina

^*Hammersmith Hospital, Histopathology Floor 1 G Block, London, United Kingdom

Background & Objective: This audit assessed the diagnostic performance of FNA in diagnosis of benign and malignant conditions of the pancreas in our department during 2013-16. We aimed to ascertain the proportion of discordant cases, and review these to determine if results alter diagnostic accuracy.

Method: All pancreatic FNA cytology specimens performed in our department during 2013-16 with corresponding subsequent surgical specimens were identified. For each case the reported cytological category was recorded (C1 – inadequate, C2 – benign, C3 – atypical; mucinous lesions, endocrine lesions C4 – suspicious for malignancy, C5 – malignant). The final surgical diagnosis was recorded. Discordant cases (benign histology vs C4/C5 cytology or malignant histology vs C2/C3 cytology) were retrieved from archives and reviewed by a cytopathologist blinded to the previous results. The cytological categories on review were compared to those originally reported.

Results: A total of 75 cytology specimens with corresponding surgical specimens were identified. A total of 17 cases (22.6%) were discordant. Slides were retrieved for all except three cases which were not available for review. Six out of 14 reviewed cases were confirmed to be correctly categorised (42.8%); the discordance being due to non-representative sampling. Of the remaining eight cases (57.2%), two were interpreted as inadequate (C1) while six were given a different cytological category on review which was at most one tier above or below the original cytological diagnosis.

Conclusion: Review of discordant cases confirms that sampling errors and inadequacy are the main causes of discordance. Discussion at MDT meetings allows avoidance of pitfalls associated with pancreatic cytology.

OFP-11-012

Assessing the healthcare provider factor and anatomical site in 4,381 thoracic lymph node fine needle aspirations using funnel plots/control charts and logistic regression

M. Bonert^*, S. Ramadan, A. Naqvi, J.-C. Cutz, C. Finley

^*McMaster University, Hamilton, Canada

Background & Objective: Thoracic lymph node fine needle aspiration (TLNFNA) is a common procedure; however, variation by healthcare provider (HCP) and anatomical site (AS) is not routinely assessed.

Method: All cytology reports for endobronchial ultrasound (EBUS)/endoscopic ultrasound (EUS) TLNFNA specimens (4,381) were retrieved from a thoracic surgery centre for July 2012-June 2017 and classified by a hierarchical free text string match algorithm (HFTSMA) into 50 diagnostic categories (Dx), four mutually exclusive diagnostic groups (benign(BEN)|suspicious(SUSP)|malignant(MAL)|insufficient(INS)), and 23 AS. Pathologist and submitting physician/surgeon (PSPS) bias was assessed using logistic regression (LR) and funnel plots|control charts (FP|CC) centred on the group median (diagnostic/capture) rate (GMR).

Results: The HFTSMA could assign an AS and Dx in ~98% cases and the coding was accurate ~97% of time in 500 audited specimens. Eleven pathologists and six SPS were involved in >150 specimens each (range 169to1115). Overall, the TLNFNAs were BEN|SUSP|MAL|INS in 40%|6%|26%|27% of specimens. Percent MAL (number of samples) varied by station; 7|4R|4L|2R|10R|11R|11L were respectively 22%(1488), 30%(1256), 25%(476), 39%(282), 27%(254), 27%(227), 37%(138). The number of pathologist outliers (P<0.05andP<0.001) of 11 from the GMR for BEN|SUSP|MAL|INS was 4and2|2and2|1and0|0and0 respectively. Submitting physicians/surgeons (SPS) outliers (P<0.05andP<0.001) of 6 for BEN|SUSP|MAL|INS was 1and1|1and0|2and1|3and3 respectively. SPS INS rate was dependent on AS. LR confirmed the FP|CC findings.

Conclusion: The HCP and AS are significant predictors of TLNFNA pathology. If HCP bias is demonstrated, it is essential to review the reports and assess for confounders. Data was provided to interested HCPs to assist in practice self-assessment and quality improvement.

Tuesday, 11 September 2018, 17:15 - 19:15, Room A3

OFP-12 | Paediatric and Perinatal Pathology

OFP-12-001

Morphological diagnostics of Takayasu arteritis in infants

A. Sapargaliyeva^*, B. Alibekov, V. Grinberg

^*Pathology Bureau, Almaty, Kazakhstan

Background & Objective: Takayasu arteritis is extremely rare in the child population. The clinical diagnosis of Takayasu arteritis in infants presents serious difficulties, and the diagnosis is rarely established during life. The aim of the study is to analyze the case of Takayasu arteritis in an infant which was not diagnosed during life.

Method: We reported an autopsy case of Takayasu arteritis occurring in a 14-week-old infant male who died on the 7th day after admission to the children's hospital

Results: An autopsy revealed left toes dry gangrene; rupture of an ascending aortic aneurysm. The histological study of aorta demonstrated round cell infiltration surrounding vasa vasorum and in the adventitia. The most severe changes were found in aortic media, which manifested itself as diffuse inflammatory infiltration and as large foci of the destruction of elastic fibers. In the aortic media, there was a proliferation of dense fibrous connective tissue, the formation of fibrous plaques. Those fibrous plaques were located in the ascending aorta, in the aortic arch, and in the descending aorta. In addition, pronounced circular cell infiltration was detected in the aortic valve and in coronary artery walls.

Conclusion: The features of the case include a rupture of the aorta and pericardial tamponade. The severity of the child's condition can be explained by the onset of aortic dissection due to large foci of elastolysis. In this case, in addition to the divergence between clinical and morphological diagnoses, we observed an overdiagnosis (sepsis and thromboembolism of the pulmonary artery), while these conditions were not confirmed by morphological examination.

OFP-12-002

Primitive mesenchymal myxoid tumour of infancy (PMMTI), a potentially highly aggressive neoplasm in infants

R. Alaggio^*, A. Zin, G. Bisogno, L. Santoro, C. Salgado

^*UPMC Children´s Hospital Pitts, Pathology, Pittsburgh, USA

Background & Objective: Primitive myxoid mesenchymal tumour of infancy (PMMTI) is a recently, described tumour with a primitive spindle/round cell morphology. BCOR internal tandem duplication is a recurrent genetic alteration shared by PMMTI and a subset of undifferentiated sarcoma (UND). In this study, we focus on UND/PMMTI with BCOR ITD to further define their clinicopathologic features.

Method: Surgical pathology and consultation files at University of Padova from 1995 to 2018 were searched for cases diagnosed as PMMTI or UND with BCOR-ITD demonstrated by FISH or RT-PCR. Clinico-pathologic features were obtained through evaluation of the medical records.

Results: 17 BCOR-ITD UND/PMMTI in the first year of life, enrolled in EpSSG or RMS 96 protocols had a M/F ratio of 8/9. Sites included head (33%), paraspinal (33%), extremities (17%) and retroperitoneum (17%). Eleven PMMTI showed round to spindle cells with prominent myxoid stroma, 6 UND were composed of round cells with minimal stroma. At last follow-up (range 2-16yr): 3 PMMTI died of disease (DOD), 1 alive in progression, 3 (2 with initial diagnosis of CIF) in remission, after relapses in 2 and metastasis in one. All 5 UND DOD with distant metastases. Five cases were recent or lost to follow up.

Conclusion: BCOR-UND are highly aggressive sarcomas with poor prognosis in 100% of cases. PMMTI, especially those morphologically resembling infantile fibrosarcoma have a better prognosis with survival in 43%, suggesting that spindle cell/CIF like morphology can define a subset of PMMTI with good prognosis.

OFP-12-003

Structural basis of complications in pregnancy using the donor egg in surrogate maternity

E. Rudenko^*, T. Demura, E. Kogan, N. Trifonova

^*FSAEI of Higher Education I.M., Pathology, Moscow, Russia

Background & Objective: Placenta pathology study in surrogate maternity may reveal predictors of pregnancy complications, and thus help to develop criteria for the selection of surrogate mothers and donor blastocysts To study the structural basics for the development of pregnancy complications in surrogate maternity.

Method: Morphological study of the placenta from 206 surrogate mothers and 193 multiparous females (after IVF with own oocytes) (comparison group).

Results: Placentas in the surrogate maternity group showed extensive pseudoinfarctions, the relative immaturity of the villous tree, the increase in the number of perivillous fibrinoid, and the fibrinoid reaction of decidual tissue. Chronic villites and deciduites of unclear etiology were more often detected in the form of focal lymphohistiocytic infiltration in the villi stroma and in decidual tissue. Conclusion: The complications development in surrogate maternity are due to the failure of tolerance formation in the mother-fetus system, which manifests itself in early pregnancy by the violation of trophoblast invasion, the lack of proper spiral arteries remodeling. Surrogate mothers more often developed preeclampsia (8.5%), premature detachment of the normally positioned placenta (4.7%), hypotonic bleeding (6.1%), tight attachment of the placenta (6.6%), delayed parts of the placenta (6.6%), premature birth (23.0%) (p <0.05).

Conclusion: These processes form the substrate for the development of utero-placental insufficiency, as well as pre-eclampsia, as the most frequent complication in the surrogate maternity group. The high incidence of villites and deciduites of unclear etiology and a significant increase in the number of fibrinoids also indicate the presence of immunopathological processes.

OFP-12-004

Salivary gland neoplasms in paediatric population. Retrospective analysis of 21 cases (2000-2018) and correlation with literature

A. Aula Olivar^*, I. Ramos-Oliver, A. Navarro, J. Camacho, L. Silva, M. Giner, M. Alberola, S. Ramón y Cajal, M. Garrido

^*Hospital Vall d´Hebron, Pathology, Barcelona, Spain

Background & Objective: Salivary gland tumours are infrequent, representing less than 3% of head and neck neoplasms. Only 5% of them occur in children. Most of these tumours are benign, being pleomorphic adenoma (PA) the prime diagnostic. Mucoepidermoid carcinoma (MEC) is the most common malignant tumour.

Method: We collect the casuistry from 2000 to 2018 at HUVH obtaining 21 cases.

Results: Of the 21 cases, 11 (52,4%) were girls and 10 (47,6%) were boys, and the average age was 12,7y. Primary lesions account for 18 (85,7%) and 3 were secondary infiltrations (14,3%). Within the primary lesions, benign tumours represent 61,1%, being all of them PA. Malignant neoplasms represent 38,9% and comprise 5 MEC (27,8%) and 2 acinic cell carcinoma (ACC)(11,1%). Secondary lesions correspond to Hodgkin lymphoma, granulocytic sarcoma and non-Langerhans cell histiocytosis. In our series, most affected salivary gland was parotid gland (13), followed by submandibular gland (5) and palate (3). Previous fine needle aspiration (FNA) was performed in 10 cases. In 8/10 the diagnosis was concordant (6PA, 1MEC, 1ACC), being the diagnostic sensibility of 80%. In the other 2 cases, both MEC, the cytologic study suggested this entity.

Conclusion: The casuistry of our center concurs with the data found in literature, although there is few series published. Malignant neoplasms in salivary gland are more frequent in paediatric population than in adults in absolute value. Previous cytologic diagnostic in salivary gland tumours in children has a high sensibility in our series and it helped to guide the diagnosis and treatment.

OFP-12-005

Identifiable stillbirth risk factors in a province. Eleven-year register

J. L. Sanz Trenado^*, R. Juárez Tosina, M. López Macías, R. Sotillo Sanchez, P. Montero Pavon, I. De Lara Simón, F. Relea Calatayud, L. Gonzalez Lopez, F. Martin Davila, V. Herrera Montoro, J. González García, M. Delgado Portela, C. C. Ramos Rodriguez, P. L. Boils Arroyo, R. Lopez Perez

^*HGU Ciudad Real, Pathology, Spain

Background & Objective: Stillbirth definition varies through countries but the commonest used one is the WHO system. In Spain, fetal deaths are officially certified from 28 weeks of gestation or if the fetus weight 500 gr or more. Nevertheless, autopsies are performed from 22 weeks in most of the centers. Our objective is to identify risk factors associated with intrauterine fetal death in our medium.

Method: We reviewed fetal autopsies from 22 weeks or 500gr or more from the five hospitals in our province that performed autopsies between the periods 2006-2016. We analysed the risk factors previously identified at the literature: maternal infections (toxoplasma, rubeola, cytomegalovirus or Herpes), AIDS, Hepatitis, mother age, parity multiple gestation, gestation week, fetal gender, intrauterine growth restriction (IGR) according to image techniques or IGR according to autopsy examination.

Results: We analysed 210 cases. Three cases of infections were detected (2 Chagas disease and one toxoplasmosis). Mother age range was 15-44 (mean: 31,3). There was 62 cases under 30 years, 111 cases between 30 and 35 years, and 37 cases above 35 years. A 47% of mothers never gave birth before, 25% were in their second gestation, and 28,2% have more than three gestations; Less than 9% of cases were classified as IGR. 53% were female 45,5% males and 1,5% undetermined.

Conclusion: Our results differs with those already published in our country. There were few cases in mothers with infections. We found a predominance of female foetuses, a predominance of primigravidas, low rates of IGR and a higher prevalence in young mothers.

OFP-12-006

Perinatal causes of death in a province. An 11 years multicentric retrospective longitudinal study

J. L. Sanz Trenado^*, R. Juárez Tosina, M. López Macías, R. Sotillo Sanchez, P. Montero Pavon, I. De Lara Simón, V. Herrera Montoro, L. González López, F. Relea Calatayud, J. González García, F. Martín Dávila, C. C. Ramos Rodriguez, M. Delgado Portela, P. L. Boils Arroyo, R. López Pérez

^*HGU Ciudad Real, Pathology, Spain

Background & Objective: Perinatal causes of death shows a huge variety among different countries and across timeline. There is still not a unified system of classification for stillbirth and perinatal deaths. Autopsy is the gold standard method to define causes of death. Our objective is to describe the causes of death in our province.

Method: We reviewed fetal autopsies from 28 weeks or 500gr or more from the five hospitals in our province (the reference hospital and district ones). We classified causes of death according to the RElevan Cause Of DEath (RECODE) system. Other variables were registered such infections, mother age, parity, gestation week, and intrauterine growth restriction.

Results: 143 autopsies were found that accomplished the mentioned criteria. We observed differences in causes of death between the different hospitals. Unclassified death rate was 34% in general. Amniotic fluid pathologies were predominant in the reference hospital and placental pathologies in the district ones. Mother age also showed differences, being higher in the district hospitals. Only three cases of infections were detected (2 Chagas dissease and one toxoplasmosis).

Conclusion: Having a system of classification it is important to analyse causes of death. It is also important to improve maternal obstetrics care. A centralize analysis that analyse and compare causes among hospital can aid to identify risks, problems and peculiarities.

OFP-12-007

Paediatric soft tissue sarcomas / borderline tumours: a series of 27 cases

M. Pimentão^*, A. Lai, M. Jerónimo, V. Almeida, C. Faria, H. Moreira, R. Almeida, J. Fraga, H. Garcia, R. Pina

^*CHUC, Anatomia Patológica, Coimbra, Portugal

Background & Objective: Paediatric soft tissue sarcomas/ borderline tumours (STS) are part of a heterogeneous group of tumours originating from embryonic mesodermal tissues during the process of differentiation into various mesenchymal tissue components of the human body. These tumours constitute 6% to 8% of all cancers in children less than 15 years of age. Of all the soft tissue sarcomas in this age group, approximately 50% to 60% are rhabdomyosarcoma (RMS), whereas the remainder are non-RMS soft tissue sarcomas, a designation that includes a variety of rarer soft tissue tumours including fibrosarcomas, synovial sarcomas, the extraosseous Ewing’s family of tumours, malignant peripheral nerve sheath tumours (MPNSTs) and inflammatory myofibroblastic tumour.

Method: We review all cases of paediatric STS from 2014 to 2018, at Centro Hospital e Universitário de Coimbra

Results: We found 27 cases: 9 females (33%), 18 males (66%), with a mean age of 7.1- years-old; 2 cases were less than one year old. RMS was the most common STS with 9 cases (33%), followed by synovial sarcoma with 5 cases (18,5%), MPNST with 4 (14,8%) and fibromatosis with 3 (11,1%). Genetic studies were performed. Correlation with imaging studies and follow-up were evaluated.

Conclusion: According to data published in literature, RMS are the most common sarcoma in the paediatric population. The imaging characteristics often are nonspecific, and the diagnosis consists of putting together the clinical, imaging and pathologic findings.

OFP-12-008

The significance of cell foetal DNA (cffDNA) and DAI-receptors (DLM-1/ZBP1) (DNA-dependent activator of IFN-regulatory factors) expression in preeclampsia

N. Nizyaeva^*, A. O. Karapetian, A. Sadekova, A. M. Krasniy, G. Khlestova, O. Baev

^*National Medical Research Center for Obstetrics, Gynecology and Perinatology, Pathology Dept., Moscow, Russia

Background & Objective: Preeclampsia is a serious pregnancy-related disorder of unknown etiology. The aim was to identify cell free fetal DNA (cffDNA) level in maternal blood and evaluate the expression of DAI-receptors in DNA-mediated activation of innate immune responses in placental tissue in cases of early-(EPE) and late-(LPE) onset preeclampsia.

Method: The concentration of cffDNA was determined by quantifying hypermethylated RASSF1A sequences using PCR method at 11-14, 24-26, 30-32 gestation weeks (wg) in 10 women with uncomplicated pregnancy and 10 PE (5-EPE, 5-LPE). By immunohistochemistry was performed on the paraffin-embedded slices of placental samples using DAI primary polyclonal antibodies (1:1000;Thermo Fisher Scientific; Ventana,Roche). The 4 placental samples up to 33 wg (early control-EC) were used as a control for EPE, 3 samples after 34 wg for LPE (late control-LC).

Results: The intensity of immunohistochemical reaction was estimated by means of program NIS-Elements. Compare to uncomplicated pregnancy cffDNA level was higher in PE (287.1±130.7 versus 893.6±539.3, 391.5±142.3 versus 1050.3±435.1, 663.2±314.7 versus 2341.7±2031.0GE/ml at 11-14, 24-26, 30-32 wg; p<0.05). DAI-receptors expression was higher in EPE group than in EC (0.145±0.019 and 0.086±0.013 respectively; p=0.006) and no differences in LPE compared to LC(p>0.05).

Conclusion: Increased cffDNA level in maternal blood may be the pro-inflammatory activity trigger and probably leading to preeclampsia

OFP-12-009

Retrospective evaluation of central nervous system defects in foetal autopsies and comparison with prenatal diagnosis

J. Fraga^*, A. C. Lai, C. Cerdeira, R. Almeida, H. Moreira, M. B. Pimentão, V. Almeida, C. Faria, R. Pina

^*CHUC, Pathology, Vila Real, Portugal

Background & Objective: Central nervous system defects (CNSD) are the most common group of malformations detected prenatally and account for substantial proportion of all congenital abnormalities. Poor timing of sonographic evaluation, rather than poor sensitivity, can be an important factor in failing to detect abnormalities. This study pretends to demonstrate CNSD and evaluate concordance between prenatal diagnosis and postmortem findings (PD/PF).

Method: Retrospective review of 1372 autopsies of fetuses performed at Centro Hospitalar e Universitário de Coimbra between 2005-2016. For evaluation of CNSD were established nine categories for classification prenatal ultrasound/magnetic resonance imaging and autopsy findings and posterior correlation.

Results: One hundred and eighty fetuses were included in this study, 84 males, 92 females and 4 undefined sex foetus. The mean maternal age was 30,53 years-old (range 15 - 45) and gestational age 20,72 weeks (range 11 – 36). The most common pathologies were myelomeningocele/Arnold-Chiari II (35,4%), midline anomalies (21,9%), anencephaly/encephaloceles (20,2%) and holoprosencephaly (9%). Excluding 24 cases without ultrasound description or non-CNSD and with severe fetal maceration, there was good agreement between prenatal diagnosis and postmortem findings, with K=0.9832 (95% Confidence Interval, 0.9601-1, p<0,0005).

Conclusion: CNSD encompass a heterogeneous group of congenital anomalies that may be isolated or appear as part of a genetic syndrome. As well as data published in literature, neural tube defects is the most common group of anomalies, followed by midline defects. The agreement between PD/PF in fetuses with CNSD is good despite the broad spectrum of defects, some of them difficult to evaluate imagiologically.

OFP-12-010

Expression of the Nkx-2.2 and FasL in human placentas with foetal trisomy 21

A. Kolobov^*, A. Pinchukova, V. Karev, O. Kolobova

^*St. Petersburg University, Dept. of Pathology, Russia

Background & Objective: Molecular pathogenesis of trisomy 21 (Down syndrome) is still incompletely understood. The biological mechanisms, including Nkx-2.2 and FasL expression, belong to potential influencing factors. The aims of this study were to compare Nkx-2.2 and FasL expressions in placentas with normal and trisomic karyotype and to associate differentially expressed Nkx-2.2 and FasL with concrete biological pathways.

Method: The placentas were collected from two groups of patients: Group A – placentas from fetuses of gestation 19-20 weeks with trisomy 21 (10 placentas); Group B – placentas from fetuses of gestation 19-20 weeks without any congenital defects and abnormal karyotype (20 placentas). Nkx-2.2 and FasL expression was studied immunohistochemically with use of mouse monoclonal antibody to Nkx-2.2 (Anti-Nkx2.2 antibody, Abcam), FasL (Diagnostic BioSystems, 1:75) and further morphometric analyses with the program ImageJ.

Results: The expression of Nkx-2.2 in placentas Group A was not found. The expression of Nkx-2.2 was found in placentas Group B. The area expression of Nkx-2.2 in endothelial cells of vessels of villi has made 0,41±0,14%. The area expression of FasL in endothelial cells of vessels of villi in placentas Group A has made 1,22±0,77%, in placentas Group B – 4,43±0,79% (p<0,05).

Conclusion: Thus, we were not found expression of Nkx-2.2 in placentas from fetuses with trisomy 21. The expression of FasL was the highest in placentas from fetuses without any congenital defects and abnormal karyotype.

Tuesday, 11 September 2018, 17:15 - 19:15, Room A4

OFP-13 | Uropathology

OFP-13-001

The depth of tumour invasion is superior to 8thAJCC/UICC staging system to predict patients’ outcome in radical cystectomy. A proposal for a new staging system

T. Tsuzuki^*, T. Nishikimi, Y. Murase, H. Iwata

^*Aichi Medical University Hospital, Japan

Background & Objective: AJCC/UICC staging system is the golden standard to predict the outcome. However, not a few studies report that pT staging (pT2 vs. pT3) may not be a prognostic factor. Also, pathological criteria of distinction between pT2 and pT3 are variable among pathologists.

Method: We retrospectively evaluated 117 bladder cancer patients who underwent radical cystectomy and reviewed the all HE slides. No patients received neoadjuvant chemotherapy. The depth of tumour invasion (DTI) was measured from normal urothelium to the deepest invaded lesion. Data on the patients’ age, DTI (1.0 mm < vs. >1.0 mm), pT stage, WHO1973 grade, and lymph node status were analyzed. Fine & Gray and multivariate Cox proportional hazard regression models were developed to predict progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS).

Results: The median age of the patients was 71 years (35–87 years). The median follow-up period was 32 months (range 1–247 months). Pathological characteristics were as follows: Median DTI 10.80mm (range 2.57 - 37.14mm), pT (pT2:pT3=38:79)、1973 WHO grading (G2:G3=28:89). In the multivariate analysis, depth of tumour invasion was significantly associated with PFS (p = .019), CSS (p = .011) and OS (p = .017). Lymph node status was significantly associated with CSS (p = .0168). pT staging was not associated with PFS (p = .786), CSS (p = .894) and OS (p = .337).

Conclusion: DTI is a more useful prognostic factor for PFS, CSS, and OS in bladder cancer than those of the AJCC/UICC pT system.

OFP-13-002

Three-dimensional analysis of clinical prostate cancer samples

E. Verhoef^*, W. van Cappellen, J. Slotman, G.-J. Kremers, A. Houtsmuller, M. van Royen, G. van Leenders

^*ErasmusMC, Pathology, Rotterdam, The Netherlands

Background & Objective: The Gleason Score (GS) is one of the most important parameters for clinical decision-making in prostate cancer (PCa), existing of individual growth patterns. The objective of this study was to elucidate on the underlying three-dimensional (3D) architecture of clinical PCa growth patterns.

Method: Formalin fixed, paraffin embedded tissues (n=46) were fluorescently stained with antibodies CK8-18 and CK5, and optically cleared in benzyl alcohol: benzyl benzoate. Imaging up to 700 micron depth was done with an SP_5 confocal microscope.

Results: The basic 3D architecture of most PCa samples consisted of tubules with branching and connections. While branching occurred sporadically in GG3 PCa, frequent and adjacent connections characterized fused GG4. GG3 formed a 3D morphologic continuum with ill-formed GG4 and cord-pattern GG5 with gradual decreasing tubule and lumen diameter, with concomitantly increased branching. Glomeruloid GG4 structures were represented by one-sided intraluminal proliferations in tumour tubules often being present at branching points. On the other hand, cribriform GG4 and solid GG5 formed a continuum of large epithelial proliferations characterized by loss of stromal contact by the majority of tumour cells. The frequency and size of inter-epithelial lumens in these proliferations decreased from cribriform to solid growth.

Conclusion: Three-dimensional reconstruction of clinical PCa reveals two fundamentally different growth patterns: 1) Gleason grade 3, ill-formed GG4, fused GG4 and cord-pattern GG5 form a 3D tubular morphologic continuum, 2) cribriform GG4 and solid GG5 both are non-tubular proliferations, while glomeruloid GG4 represents an intermediate between both basic structures.

OFP-13-003

Relationship of E-cadherin, beta-Catenin, CD44 and Bcl-2 expression with different gene fusion subsets of prostate cancer and PTEN status

N. Juanpere Rodero^*, S. Hernández-Llodrà, M. Lorenzo, S. de Muga, J. Gil, R. Albero, I. Vázquez, L. Cecchini, L. Fumadó, B. Lloveras, J. Lloreta-Trull

^*Hospital del Mar-Parc de Salut, Pathology, Barcelona, Spain

Background & Objective: In ERG+ prostate cancer (PrCa), we reported that combined ERG expression and Prostein and PTEN loss (3-hit) is associated with high grade and stage and shorter PSA progression-free survival. We have investigated the relationship of these genes with E-cadherin, β-Catenin, CD44 and Bcl-2, as markers of epithelial-mesenchymal transition (EMT), stemness and apoptosis regulation in a series of PrCa.

Method: An immunohistochemical study of all these molecules was performed in a TMA series with 220 radical prostatectomies (Parc de Salut MAR Biobank, MARBiobanc, Barcelona, Spain).

Results: Bcl-2 expression was found in 44.7% ERG+ versus (vs) 26.7% ERG- cases (p=0.015). CD44 was positive in 68.2% ERG- (wild type) vs 52.2% ERG+ PrCa (p=0.044). E-cadherin loss was found in 45.3% PCa cases with Prostein loss and in 13.6% Prostein wild type (wt) cases (p<0.0001). β-Catenin was lost in 38.4% cases with Prostein loss vs 24.6% Prostein wt cases (p=0.042). E-cadherin loss was found in 35.6% PCa with PTEN loss vs 17.3% PTEN wt cases (p=0.0035). Finally, E-cadherin loss was detected in 71.4% cases with the 3-hit compared to 13.4% non-3-hit cases (p<0.0001).

Conclusion: ERG- cases are associated with stemness and ERG+ cases, with inhibition of apoptosis. EMT-related features are more frequent in the ERG+ subset of PCa with loss of Prostein and PTEN. All these findings mark relevant steps in the progression of PCa.

Supported by: FIS/Carlos III/FEDER/PI15/00452, Spanish Ministry of Health.

OFP-13-004

Incidence of penile squamous-cell carcinoma and its relation with the Human papillomavirus: a 10-year review of cases at a university hospital

S. J. Sánchez Luizaga^*, V. Blanco Lorenzo, I. Prado Graña, C. Bueno Fernández, L. Rodríguez Fernández, M. d. la Paz González Gutiérrez, A. Alonso Fernández-Velasco, I. Husain Calzada, A. Astudillo González

^*Hospital Central de Asturias, Pathological Anatomy, Oviedo, Spain

Background & Objective: According to current publications, 30 - 40 % of all Penile Squamous-cell carcinoma (SCC) are related to concomitant infection with Human Papillomavirus (HPV) whose predominant genotype is the high-risk HPV. Objective: Determine the incidence of Penile SCC in our institution during the last decade (2008-2017), its relation to HPV infection and correlation with the histologic subtype, stage and anatomical location.

Method: Retrospective and descriptive study. 44 patients diagnosed with Penile SCC at Hospital Universitario Central de Asturias (HUCA) from 2008 to 2017 have been included in this study. Anatomical location, histologic subtype and pathological stage have been determined for every case. Immunohistochemical stains have been realized of p16, pan-HPV and high-risk-HPV.

Results: The average age of the 44 cases was 68 years old. 77 % (34) presented Conventional Penile SCC, 13.6 % (4) presented Warty SCC and 4.5 % (2) Papillary SCC. 43 % (19) of the cases showed HPV infection. 67% (13) of penile SCCs related to HPV infection were at stages I-II. 79 % (15) of the HPV-associated carcinoma corresponded to conventional penile SCC, and these latter represented only 49 % of all conventional penile SCC (34).

Conclusion: Only 43 % of all cases with penile SCC studied presented relation with HPV infection. Most of HPV-associated Penile SCC were at stages I-II. The most common histological subtype was conventional Penile SCC followed by warty SCC. Our data are correlated with global tendency.

OFP-13-005

FH deficient renal cell carcinoma and FH deficient-like renal cell carcinoma: morphologic comparative study of 23 genetically tested cases

K. Pivovarcikova^*, K. Trpkov, C. Magi-Galluzzi, M. Pane Foix, M. Ulamec, B. Saskova, O. Hes

^*Biopticka laborator s.r.o., Plzen, Czech Republic

Background & Objective: Recent publications dealing with aggressive renal carcinomas associated with HLRCC syndrome expanded the morphologic spectrum of the renal tumours associated FH gene abnormalities, emphasizing the presence of papillary, tubulary or mixed architecture, eosinophilic cells and red macronucleoli with perinucleolar halos.

Method: Architecture, cytology, presence of prominent nucleoli and perinucleolar clearing were analyzed in 13 FH deficient renal cell carcinomas (FHRCC) with proved FH mutation/LOH and 10 FH deficient-like renal cell carcinomas (FHLRC) without proved FH mutation/LOH.

Results: FHRCC cohort included 8 males and 5 females, with age range of 24-65 years, and tumour size of 0.9-18 cm. FHLRC group included 5 males and 5 females, age range 21-82 years, and tumour size of 2.6-11 cm. FHRCC: mixed pattern was present in 7/13 cases, papillary in 3/13, tubulopapillary-cystic in 2/13 and solid sarcomatoid in 1/13. Eosinophilic cells were present in 8/13, macronucleoli in 13/13 (4 focally), perinucleolar clearing in 10/13 (7 focally). FHLRC: mixed pattern was present in 5/10 cases - tubulopapillary pattern was present in 4/10, tubulo-cystic in 1/10, only papillary in 4/10, and tubulary 1/10. Macronucleoli were present in 10/13 (1 focally), perinucleolar clearing in 8/10 (2 focally).

Conclusion: Renal cell carcinomas from both groups showed significant overlap in histological growing pattern and cytologic features. It is impossible to separate FHRCC from FHLRC based only on morphology. Due to the limitations of immunohistochemistry, analysis of FH gene is only reliable method for separation of FHRCC from their mimickers.

OFP-13-008

Prognostic value of E-cadherin and P-cadherin immunoexpression in pT3 prostate cancer

J. Lobo^*, C. Ferreira, L. Antunes, P. Lopes, R. Henrique

^*IPO Porto, Dept. of Pathology, Portugal

Background & Objective: Prostate cancer (PCa) represents the most common malignancy and a major cause of cancer-related death in men. Despite being referred as “high risk cancer”, pT3 tumours do not exhibit a uniformly poor prognosis after radical prostatectomy (RP). Loss of E-Cadherin has been associated with poor prognosis, while the role of P-Cadherin in PCa is still widely debated. We aimed to assess the prognostic value and impact on survival of E-Cadherin and P-Cadherin immunoexpression in pT3 PCa.

Method: RP specimens of 102 PCa patients were retrospectively queried (1999-2014). All patients were treated at our institution by the same multidisciplinary team. Clinical and histological material was reviewed. A representative block was selected for tissue micro-array (TMA) construction(3cores/case). E-Cadherin immunoexpression was assessed with digital image analysis system (H-score method), with cases categorized as E-Cadherin-high/low when above/below the 30th percentile(P30). For P-Cadherin, the scoring criteria currently used for HER2 in gastric cancer were applied.

Results: Patients with pT3b (vs. pT3a) and higher Gleason Groups (vs. lower) displayed worse disease-specific survival (DSS) [HR:4.58, 95%CI:1.49-14.05; HR:9.65, 95%CI:1.25-74.89]. There was an association between E-Cadherin and P-Cadherin immunoexpression (p=0.019); considering E-Cadherin-low patients, 97% were P-Cadherin negative. E-Cadherin-low patients displayed worse DSS, although it did not reach statistical significance (HR:2.65, 95%CI:0.81-7.88). However, considering only pT3b patients, those with low E-Cadherin immunoexpression displayed significantly worse overall-survival (OS) and DSS (HR:3.69, 95%CI:1.18-11.50; HR:5.90, 95%CI:1.40-24.81). No significant differences in survival were found for P-Cadherin.

Conclusion: Lower E-Cadherin immunoexpression discriminated a subgroup pT3b patients with poorer survival. The role of P-Cadherin in PCa might be context-dependent and deserves further investigation.

OFP-13-009

FOXC2 regulating epithelial-mesenchymal transition is a marker of aggressive prostate cancer

A. Børretzen^*, K. Gravdal, S. A. Haukaas, C. Beisland, L. A. Akslen, O. J. Halvorsen

^*Haukeland University Hospital, of Pathology, Hjellestad, Norway

Background & Objective: Epithelial-mesenchymal transition (EMT), characterized by reduced E-cadherin and increased N-cadherin expression (E/N-cadherin switch), is important for tumour cell invasion and metastasis, and is a feature of aggressive carcinomas. The objective of our study was to examine the EMT-regulator FOXC2 and the cell adhesion molecules E- and N-cadherin, in different human prostatic tissues with focus on EMT, clinico-pathologic phenotype and patient prognosis.

Method: Sections from 338 radical prostatectomies (Haukeland University Hospital, Norway, 1986-2007), 33 castration resistant prostate cancers, 33 soft tissue metastases, 13 skeletal metastases and 41 prostatic hyperplasias were immunohistochemically stained for FOXC2, E- and N-cadherin.

Results: In univariate survival analyses, using the clinically important subgroup of 198 patients with Gleason score 7, high FOXC2 expression and E/N-cadherin switching were significantly associated with shorter time to clinical recurrence, skeletal metastases and cancer specific death. In multivariate Cox proportional hazard analysis, high FOXC2 (HR 1.9, p=0.018; HR 3.7, p=0.003; HR 4.9, p=0.001) and the E/N-cadherin switch (HR 2.6, p=0.009; HR 4.1, p=0.002; HR 7.6, p<0.0005) were independent predictors of time to these end-points, together with Gleason grade groups (GG3 vs. GG2) and pathologic stage (>=pT3 vs. pT2). In benign prostatic hyperplasia, FOXC2 was significantly weaker than in the other tissue groups, and E/N-cadherin switching was not observed.

Conclusion: FOXC2 expression and a switch from E- to N-cadherin predict aggressive prostate cancer. Factors regulating or signifying EMT can be useful as prognostic biomarkers and are potential targets of cancer therapy.

OFP-13-010

PBRM1 and BAP1 expression in renal cell carcinoma

L. Kuthi^*, E. Fallmann, A. Jenei, B. Pósfai, A. Maráz

^*University of Szeged, Dept. of Pathology, Hungary

Background & Objective: PBRM1 and BAP1 genes are located on chromosome arm 3p, which is deleted in the majority of patients with clear cell subtype of renal cell carcinoma (RCC). Here, the loss of expression of PBRM1 and BAP1 proteins was studied and correlated with the pathological features in RCC subtypes.

Method: Immunohistochemistry was performed on FFPE samples of 73 consecutive RCC nephrectomy or biopsy specimens (59 clear cell, 6 chromophobe, 5 papillary, 2 unclassified and 1 clear cell papillary) to evaluate PBRM1 and BAP1 staining of the nuclei. The reactions were simply read as positive or negative. None of the patients received prior therapy.

Results: The loss of PBRM1 or BAP1 protein was observed in clear cell RCC, while in the non-clear cell types both markers were retained. In clear cell RCC, PBRM1 and BAP1 expression was PBRM1+ BAP1+ in 29.8% of tumours, PBRM1− BAP1+ in 44%, PBRM1+ BAP1− in 15.2% and PBRM1− BAP1− in 11%. We compared PBRM1+ BAP1+ clear cell RCCs with PBRM1− or BAP1− cases, and we found that the latter were associated with high ISUP nuclear grade (p=0.021), but the pT stage (p=0.44), the tumour size (p=0.85) and the presence of necrosis (p=0.98) displayed no significant associations.

Conclusion: Loss of PBRM1 and BAP1 appears to be specific for clear cell RCC, thus their use as clear cell RCC specific markers should be considered. Also, the inactivation of PBRM1 or BAP1 may facilitate tumour dedifferentiation, and it may worsen the patient outcome.

OFP-13-011

Multi-stage pathological and immunohistochemical characterisation of N-butyl-N-(4-hydroxybutyl)-nitrosamine-induced murine bladder cancer

J. Fontugne^*, J. Wong, N. Karboul, R. Leclerc, A. Nicolas, D. Meseure, Y. Allory, I. Bernard-Pierrot, F. Radvanyi, M. Sibony

^*Institut Curie, UMR 144 Molecular Oncology, Paris, France

Background & Objective: N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-induced bladder tumours in mice represent an attractive model of muscle-invasive bladder cancer (MIBC), which mimicks the basal-like transcriptomic subgroup. Lineage tracing studies in mice suggested that MIBC, including basal tumours, arise from carcinoma in situ (CIS) lesions. However, in routine pathology practice, the majority of human CIS express a luminal immunohistochemical (IHC) phenotype CK20+. In this context, we sought to characterize early stage lesions occurring in BBN-exposed mice, using IHC markers of basal and luminal subtypes

Method: To study multiple stages of tumour progression, 35 mice bladders were obtained at different time points following oral BBN exposure of a maximum of 14 weeks. Morphological and IHC analysis of basal (CK5, CK6, CK14), luminal (CK20, GATA3, FOXA1) and proliferation (Ki67) markers were performed.

Results: Morphological analysis identified a spectrum of lesions during BBN exposure, including isolated early lesions -hyperplasia (n=1), dysplasia (n=3) or CIS (n=4)- pTa (n=13), pT1 tumours (n=10) and MIBCs (pT2 and pT3, n= 6). Squamous differentiation was observed in 79% of pTa-pT3 tumours. A basal IHC pattern was identified in 2 of 3 dysplasia lesions and in all CIS lesions, which were associated with high proliferation (Ki67≥20%). pTa to pT3 cases displayed a basal-like phenotype in 86% of cases.

Conclusion: Our study shows that BBN-induced bladder tumours at both CIS and invasive stages are of basal-like IHC phenotype, suggesting that BBN-treated mice may represent a model of basal CIS. Further genomic and transcriptomic analyses of stage-specific lesions following laser-capture microdissection are ongoing.

OFP-13-012

Osteonectin overexpression in the case of prostate cancer with intraluminal inclusions

A. Piddubnyi^*, R. Moskalenko, I.-M. Radomychelski, M. Lyndin, V. Sikora, A. Romaniuk

^*Sumy State University, Pathology Dept., Ukraine

Background & Objective: Osteonectin (OSN) is secreted by osteoblasts during bone formation, initiating mineralization and promoting mineral crystal formation at sites of ectopic calcification. Also OSN was found in many types of human malignant tumours. The aim is to study the OSN expression in patients with prostate cancer (PC) and the presence of intraluminal inclusions (prostatolithes and amyloid cells).

Method: OSN expression was investigated in tumours and in the adjacent prostatic tissue of 30 PCs with intraluminal inclusions and 30 PCs without them by immunohistochemistry. In each group 15 samples refer to moderately differentiated G2 and low-differentiated G3 tumours. Samples were fixed, embedded in paraffin, and analized for OSN accumulation using the anti-OSN antibody, followed by DAB detection substrate and counterstained with Mayer’s haematoxylin.

Results: OSN expression was increased in PC tissues with pathological inclusions in comparison to those without them (p<0.001, Student test). Osteonectin was mostly localized in tumour cells cytoplasm, its expression was not observed in tumour microangiourea cells and in stroma. It was found that the OSN expression by tumour cells reduced during reduction of the malignant tumour differentiation (comparison of subgroups G2 and G3) (p<0.001 and p<0.01 respectively for groups I and II).

Conclusion: OSN overexpression in tumours and in the adjacent prostatic tissue of PCs with intraluminal inclusions may be regarded as a prospective role for the osteosteogenic phenotype development of tumour cells and for the bone metastasis promotion.

Tuesday, 11 September 2018, 17:15 - 19:15, Room B1

OFP-14 | Joint Session: Endocrine Pathology / Head and Neck Pathology

OFP-14-001

Differentiated thyroid carcinoma of the paediatric age: genetic and clinical scenario

F. Galuppini^*, P. Facchin, S. Barollo, S. Watutantrige-Fernando, F. Vianello, A. Fassina, M. Rugge, C. Mian, G. Pennelli

^*Università Studi di Padova, DIMED, Italy

Background & Objective: Follicular-derived differentiated thyroid carcinoma is the most common endocrine malignancy in children. The different clinical and pathological features between paediatric and adult thyroid carcinomas could be related to a different genetic profile. However, few studies are currently available and most of them involved a limited number of patients and mostly focused on radiation-exposed population. A greater knowledge of the genetics might improve the diagnostic frame and lead to an individualized therapy.

Method: We studied 57 paediatric patients who underwent surgery for diagnosis of differentiated thyroid carcinoma between 2000 and 2017. The presence of mutations in BRAF, NRAS, PTEN, PIK3CA genes, and in TERT promoter, were analyzed through sequencing. RET/PTC rearrangement has been investigated with Fluorescent in situ hybridization. Clinical-molecular features of paediatric patients were compared with those of 165 adult patients.

Results: In paediatric age, male gender and subjects < 15 years have a more extensive disease and more frequent lymph nodes and distant metastasis. Compared to adults, in paediatric patients there is a more frequency of lymph nodes and distant metastasis (p=0,01); moreover, paediatric patients are more prone to have a second treatment (p<0,01). The frequency of BRAFV600E mutation is lower in paediatric DTCs (p<0,01). NRASQ61R, NRASQ61K and TERTC250T are rare in children and adolescents; no mutations were found in PTEN and in PIK3CA.

Conclusion: Paediatric differentiated-thyroid cancer has a greater aggressiveness at diagnosis and a greater risk of recurrence than adult’s one. Differently from adult, point mutations have not a genetic key role.

OFP-14-002

Specific molecular mechanisms of tumour progression from well differentiated to poorly differentiated thyroid carcinomas identified by next generation sequencing analysis

M. Volante^*, S. Vatrano, S. Carollo, J. Giorcelli, A. Votta, L. Daniele, G. De Rosa, M. Papotti

^*University of Turin, Dept. of Oncology, Orbassano, Turin, Italy

Background & Objective: The molecular background of thyroid cancer histotypes, including poorly differentiated carcinoma, has been investigated in recent years using high throughput technologies. However, molecular studies specifically designed to explore the mechanism of tumour progression from well-to-poorly differentiated forms are still missing

Method: Fifteen cases of poorly differentiated carcinomas with associated well-differentiated papillary or follicular components have been micro-dissected to isolate and characterize at the molecular level the two tumour populations using the Oncomine Focus Assay (IonTorrent platform, ThermoFisher Scientific) covering somatic CNA and fusions in 52 cancer relevant genes

Results: Eleven cases yielded adequate DNA and RNA for next generation sequencing analysis. A high prevalence of alterations in the RAS (5/11 cases) and PIK3CA/AKT1 (7/11 cases) pathways was observed, in most instances mutually exclusive. In 10/12 mutated cases, RAS and/or PIK3CA/AKT1 mutations were present in both tumour components with similar allelic frequencies, thus underlying their role as driver mutations. However, all but one case showed discordant molecular profiles at least in one of the genes investigated. RET and MET were predominantly altered in the well differentiated components, only (1/1 and 2/3 mutated cases, respectively). By contrast, EGFR and PDGFRa/KIT genes were altered almost exclusively in the poorly differentiated component (2/3 and 3/4 mutated cases, respectively, the latter genes always associated to cases with well-differentiated papillary histotype)

Conclusion: These data show a high molecular heterogeneity in poorly differentiated carcinomas associated with a well differentiated component, and identify novel molecular markers of tumour progression including tyrosine kinase receptors that might represent novel potential therapeutic targets

OFP-14-003

The “don’t eat me” signal CD47 – a therapeutic option in human anaplastic thyroid carcinoma?

M. Dettmer^*, M. Roelli, M.-H. Wasmer, F. Brühl, S. Forster, R. S. Maire, S. Di Pancrazio, M.-D. Ruepp, A. M. Schmitt, P. Krebs, R.-P. Charles, C. Schürch

^*University of Bern, Switzerland

Background & Objective: Anaplastic thyroid carcinoma (ATC) is one of the most aggressive human cancers and has a dismal prognosis. CD47 is a “don’t eat me” signal which prevents cancer cells from phagocytosis by binding to SIRP-alpha on macrophages. So far, the role of macrophages and the CD47-SIRP-alpha signaling axis in ATC is not well understood.

Method: We analyzed 20 primary human ATCs for macrophage markers and CD47 expression by immunohistochemistry. ATC cell lines were assessed for CD47 expression by flow cytometry. CD47 was blocked in in vitro phagocytosis assays of co-cultured macrophages and ATC cell lines. Anti-CD47 antibody treatment was administered to immunocompromised mice subcutaneously xenotransplanted with ATC cell lines as well as to double-transgenic mice that develop orthotopic ATCs after tamoxifen induction.

Results: Human ATCs had a mean macrophage infiltration of 25%, a weak CD47 expression and a moderate expression of calreticulin, the dominant pro-phagocytic molecule. Surface CD47 and calreticulin were highly expressed in 8/8 ATC cell lines as analyzed by flow cytometry. Blocking CD47 increased phagocytosis of ATC cell lines in vitro compared to isotype control. Anti-CD47 antibody treatment significantly delayed tumour growth and increased the frequency of intratumoural macrophages in ATC xenotransplanted mice. In double-transgenic mice, anti-CD47 treatment resulted in increased intratumoural macrophage frequencies without affecting tumour growth kinetics.

Conclusion: ATCs express CD47 and are heavily infiltrated by macrophages. Anti-CD47 treatment increases phagocytosis of ATCs by macrophages in vitro and in vivo and might be a promising therapeutic option for ATC patients.

OFP-14-004

Neuroligin 2 is a novel immunomarker of neuroendocrine cells and tumours

J. Metovic^*, L. Bertero, L. Righi, C. Musuraca, F. Veneziano, F. Maletta, F. Bussolino, M. Volante, M. Papotti

^*University of Torino, Dept. of Oncology, Italy

Background & Objective: Neuroligin 2 (NLG2) belongs to a family of proteins with predominant brain localization whose activities are related to inhibitory synapses. A strong immunoreactivity for NLG2 was incidentally observed by our group in islet cells of pancreas. This prompted an extensive investigation of NLG2 expression in other neuroendocrine (NE) cells and tumours.

Method: A series of 236 NE-neoplasms was collected from the pathology files of the University of Turin and tested immunohistochemically for NLG2 (polyclonal rabbit antibody, Synaptic Systems, Germany). These included lung carcinoids (100), gastroenteropancreatic NETs (22), parathyroid (20) and pituitary (9) adenomas, medullary thyroid carcinomas (30), pheochromocytomas (15), high grade pulmonary and extrapulmonary NE carcinomas (17), Merkel cell carcinomas (10), mixed adeno-NE carcinoma (8), and NE-breast carcinomas (5). Control non-NE lung, breast, colorectal, pancreatic adenocarcinomas were evaluated.

Results: NLG2 was expressed in 94% of NENs, irrespective of the site of origin, with a diffuse cytoplasmic distribution in variable intensity and percentages of tumour cells (5-90%). Peritumoural normal pancreatic, intestinal and pulmonary neuroendocrine cells had a similar immunoreactivity. Well differentiated tumours generally expressed NLG2 to a higher extent than high grade NE carcinomas. All control non-NE neoplasias were negative, except occasional cells in rare pancreatic and breast adenocarcinomas, representing focal NE differentiation as demonstrated by chromogranin A co-localization in double stainings.

Conclusion: NLG2 may be a valid adjunct to other pan-NE markers to define the NE phenotype irrespective of the primary location, with special reference to well differentiated neoplasias.

OFP-14-005

The role of class III beta-tubulin in invasive potential of thyroid carcinoma and its clinical significance

H. Y. Na^*, J.-Y. Choe, S. A. Shin, M. Park, J. E. Kim

^*SNU Bundang Hospital, Pathology, Gyeonggi-Do, Republic of Korea

Background & Objective: Class III beta-butulin (TUBB3) is known to take part in the invasive growth and metastasis in some tumours. In this study we aimed to evaluate clinicopathologic significance TUBB3 in thyroid carcinoma.

Method: A total of 166 cases of papillary thyroid carcinoma (PTC), including 136 conventional (C) PTC, 13 follicular variant (FV) PTCs and 17 anaplastic thyroid carcinomas (APC), were collected and immunohistochemistry (IHC) for TUBB3 was performed. Expression of TUBB3 protein and mRNA were investigated in normal thyroid epithelial cells, CPTC and APC cell lines.

Results: Expression of TUBB3 were significantly different among the three types of tumours, which revealed higher proportion and intensity of both tumour cells and stromal cells in CPTC and APC than in FV PTC. In CPTC group, the proportion of TUBB3 in tumour cells was associated with older age. And the intensity of TUBB3 in tumour cells was associated with lymph node metastasis. In survival analysis, the proportion of tubulin was associated with inferior recur-free survival (p=0.05). In vitro cell line studies, western blot and RT-PCR analysis in baseline and after invasion assay were generally concordant with the IHC results with APC showing higher expression of TUBB3 in both baseline and invasion assay than in CPTC.

Conclusion: Our results suggest that tubulin might participate in invasive growth and metastasis in PTC, being a potential target for therapy in patients with aggressive disease course.

OFP-14-006

Non-invasive follicular thyroid neoplasm with papillary-like nuclear features: clinicopathological aspects, outcome and genetic profile of 42 cases

R. Jouini^*, S. Chaieb, F. Khanchel, W. Koubaa, M. Ferchichi, A. Chadli, E. Ben Brahim

^*Habib Thameur Hospital, Pathology, Tunis, Tunisia

Background & Objective: It is now admitted that non-invasive encapsulated follicular variant of papillary thyroid carcinoma has an indolent clinical behavior. Recently, the term non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was introduced to emphasize the low biological potential of these tumours. The objective of this study was to describe clinicopathological, evolutive features and molecular profile of a series of NIFTP

Method: After reviewing all the slides of encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) from the archives of Pathology Department of Habib Thameur Hospital of Tunis between January 2000 and August 2015, 42 cases fulfilled the criteria of NIFTP. The mutational profile, using pyrosequencing, of codon 600 of the BRAF gene and codons 12, 13, 59, 61, 117 and 146 of the NRAS and KRAS genes were studied.

Results: The mean age was 41 years with a sex ratio M/F of 0,1 (4/38). Fourteen patients (95%) have done total thyroidectomy. The mean size of the tumour was 3,6 cm. No lymph node metastases were observed in all cases. Thirtyfour (94%) NIFTP were classified as stage I or II according to UICC. Molecular analysis revealed RAS gene mutations in 18 cases (45%), BRAF gene mutation in 5 cases (12%). Eighteen cases (43%) were not mutated. The mean follow-up was 30 months. No patient died, recurred or had distant metastasis during follow-up.

Conclusion: Histological, molecular and evolutive characteristics of NIFTP confirms their low malignant potential and provides supporting evidence for the nomenclature shift and the inclusion of NIFTP into the latest WHO endocrine tumour classification scheme.

OFP-14-007

Impact of race/ethnicity on oncogenic driver mutations prevalence and outcomes in thyroid nodules

I. Laklouk^*, C. Ponchiardi, S. Cerda

^*Boston University, Dept. of Pathology, USA

Background & Objective: A previous study showed evidence of racial disparities in clinical behavior of thyroid carcinoma subtypes. We aimed to evaluate the racial disparities impact on oncogenic driver mutations in a subset of thyroid neoplastic lesions.

Method: We identified 424 thyroid nodules with corresponding fine needle aspiration and ThyroSeq testing performed at our institute between February 2015 and September 2017. The self-reported race/ethnicity distribution was 29% whites, 31% blacks, 20% Hispanic, 10% Asians, and 12% Unknown.

Results: Of 424 nodules, 125 with definitive histologic diagnosis. The surgical resection prevalence was 30% among racial/ethnic subgroups [p=0.21]. A 64.8% of the resected nodules had a neoplastic lesion ( 62 had positive molecular-test ). Classic Papillary Thyroid Carcinoma (PTC) was 43.33% in whites and 33.33% in Hispanics; Follicular Variant Papillary Thyroid Carcinoma (FVPTC) was 31.58% in blacks; Non-invasive Follicular Thyroid Neoplasm with Papillary-like Nuclear Features (NIFTP) was 57.14% in Asians [p=0.007]. In PTCs, whites (54% BRAF-V600E, 38% RAS mutations); blacks (100% BRAF-V600E); Hispanics (40% BRAF-V600E, 20% NRAS); and Asians (67% NRAS). In FVPTCs, blacks (83% RAS mutations); whites (33% NRAS); and Hispanics (50 % NRAS). No FVPTC was diagnosed among Asians. 57% of NIFTPs had RAS mutations. No NIFTPs were diagnosed in white and blacks.

Conclusion: We found racial/ethnic disparities in the genomic alterations of the subtypes of neoplastic thyroid lesion including prevalence of BRAF and RAS mutations, and other oncogenic drivers detected by ThyroSeq test. These results stress the importance of maintaining awareness of how racial differences may affect the diagnostic utility of molecular testing platforms and thus influence patient management.

OFP-14-008

Mutational analysis of ossifying fibromas of the jaws and craniofacial skeleton

L. Martin^*, P. Speight

^*School of Clinical Dentistry, Dept. of Oral Pathology, Sheffield, United Kingdom

Background & Objective: Ossifying fibroma (OF) is a benign neoplasm of the jaws and craniofacial skeleton characterised by progressive growth with bony expansion. Three distinct variants are recognised: cemento-ossifying fibroma (COF), and two juvenile types: psammomatoid (JPOF) and trabecular (JTOF). There are considerable clinicopathological overlaps between these lesions, resulting in significant diagnostic challenges. Further genetic analysis of OF is required to better understand their origins and identify potential diagnostic markers. We aimed to establish protocols for whole exome sequencing (WES) from decalcified, formalin-fixed paraffin-embedded (dFFPE) tissue, and to explore possible genetic origins of OFs.

Method: 3 different methods of DNA extraction were assessed (Qiagen QIAamp, Qiagen GeneRead, Covaris truXTRAC) and WES was conducted on 8 cases of OF. Alignment and variant calling were performed with online analytical software Galaxy tools. Variant annotation and prioritisation used multiple tools, including, Ensembl VEP, ClinVar and SIFT, to identify key variants based on their significance to tissue expression and known pathogenicity.

Results: The Qiagen GeneRead method gave the best yield of DNA. 1,615 variants (minimum read depth = 35) were filtered to 9 variants within 7 genes (BCLAF1, ANKHD1, CDC27, FARP2, FRA10AC1, HEXB and PDE4DIP) based on tissue expression, impact type and predicted pathogenicity. Variants did not distinguish between OF types. No common variants were identified amongst odontogenic or non-odontogenic samples.

Conclusion: DNA extraction from dFFPE tissue can result in a sufficient yield for conducting WES. This study has identified new candidate gene mutations, opening new avenues of investigation for potential biomarkers in this group of rare lesions.

OFP-14-009

Defining HPV-driven neoplastic transformation infection in oropharyngeal carcinoma. A moving target in head and neck oncology

P. Morbini^*, G. Ferrario, P. Alberizzi

^*University of Pavia, Dept. of Molecular Medicine, Italy

Background & Objective: Oropharyngeal squamous cell carcinoma (OPSCC) treatment relies on HPV status definition. Viral oncogene mRNA identification is the gold standard for HPV-driven oncogenesis, but for its technical complexity algorithms pairing DNA and p16 expression, as indirect evidence of E6 activation, are currently used. Recently, HPV oncogene mRNA in situ hybridization (ISH) on routine slides has been proposed as a stand-alone test for OPSCC classification. We compared mRNA rt-PCR and ISH with HPV DNA and oncogene target expression in 54 consecutive OPSCC to define their ability to identify oncogenic infections

Method: Frozen samples were used for HPV E6 mRNA qRT-PCR. HR-HPV mRNA ISH, SPF10 LiPA genotyping and mmunostains for p16, pRB, p53 were performed on fixed samples

Results: HR HPV mRNA qRT-PCR was positive in 31 samples (57.4%) and mRNA ISH in 24 (44.4%). Of the 7 mRNA PCR+/ISH- samples, 2 expressed p16 and HPV16 DNA; 5 were negative for p16 but expressed HR-HPV DNA. These 5 samples also expressed pRB. All HR-HPV DNA+ cases, including the 5 that were p16-, expressed viral mRNA by qRT-PCR; all HR-HPV DNA- cases, including 4 that were p16+, were negative for viral mRNA

Conclusion: Discordant cases complicate studies comparing HPV identification strategies. We confirmed the occurrence of p16 expression independent of viral oncogenesis. Our findings of mRNA qRT-PCR+/ISH- cases with no p16 expression/pRB loss challenges the assumption of a necessary correlation between HPV oncogene expression, pRB pathway inactivation, and more generally, HPV-driven neoplastic transformation, and suggest that analysis of HPV-oncogene target proteins may improve classification of discordant OPSCC.

OFP-14-010

The need for intra-operative assessment of resection margins in oncological surgery, with focus on the head and neck region: a review of the literature

F. van Lanschot^*, M. van der Kamp, L. Oudijk, R. Smits, I. ten Hove, H. Mast, J. Hardillo, D. Monserez, C. Meeuwis, A. Sewnaik, R. Verdijk, G. van Leenders, V. Noordhoek Hegt, P. Ewin - Graham, T. Bakker Schut, E. Wolvius, F. van Kemenade, R. J. Baatenburg de Jong, G. Puppels, S. Koljenovic

^*Erasmus MC, Otolaryngology, Rotterdam, The Netherlands

Background & Objective: Intra-operative assessment of the resection margins can help the surgeon to achieve complete tumour removal. However, there is no consensus on the indication for performing intra-operative assessment. The aim of this study is to give an overview of literature on the need for intra-operative assessment and to compare two different methods: specimen driven and wound bed driven.

Method: A literature search was performed in the Medline-, Embase- and the Cochrane Collaboration, from 2000 to 2017. The studies were clustered per surgical discipline and anatomical site. Information on type of study, type of surgery, frequency and method of intra-operative assessment, and the author’s results/conclusion were recorded.

Results: Sixty-eight studies reporting on intra-operative assessment in oncological surgery were found: 6 skin cancer surgery, 6 gynaecology, 13 breast, 14 urology, 13 gastro-intestinal and 14 head and neck. The frequency and method of intra-operative assessment, and the author’s conclusions varied widely between surgical disciplines. Most studies recommended the intra-operative assessment. For the head and neck region, 4 studies compared the two different methods and recommended the specimen driven assessment.

Conclusion: This review demonstrates that there is relatively scarce evidence on the need of intra-operative assessment of resection margins, implying that this technique is not standard practice in oncological surgery. However, for head and neck, all authors recommend specimen driven intra-operative assessment. This is in accordance with the experience at our institute. Finally, current American Joint Committee on Cancer (8th edition) guidelines also recommends specimen driven intra-operative assessment in the head and neck region.

OFP-14-011

Relocation of inadequate resection margins in the wound bed during oncological surgery

F. van Lanschot^*, H. Mast, J. Hardillo, D. Monserez, I. ten Hove, E. Barroso, F. Cals, R. Smits, M. van der Kamp, C. Meeuwis, A. Sewnaik, R. Verdijk, G. van Leenders, V. Noordhoek Hegt, T. Bakker Schut, R. J. Baatenburg de Jong, G. Puppels, S. Koljenovic

^*Erasmus MC, Otolaryngology, Rotterdam, The Netherlands

Background & Objective: Intra-operative assessment of the resection margins on the specimen provides immediate feedback to the surgeon on whether an additional excision is needed. However, relocation of an inadequate margin from the specimen to the wound bed has been shown to be difficult. The objective of this study is to assess a new method for relocation of inadequate tumour resection margins in the wound bed after intra-operative assessment of the resection specimen.

Method: During surgery for oral cavity cancer, the surgeon placed numbered tags on both sides of the resection line in a pair-wise manner. The tags were placed along superficial and deep resection lines. After resection, one tag of each pair remained fixed on the specimen and the other tag remained in the wound bed. Upon detection of an inadequate margin in the resection specimen, the numbered tags were used to relocate the inadequate resection margin in the wound bed.

Results: The method was applied during 80 resections for oral cavity cancer, for which intra-operative specimen-driven assessment of resection margins was performed. In 31 resections an inadequate margin was detected. Based on the paired tagging method an accurate additional resection was achieved.

Conclusion: Paired tagging facilitates a reliable relocation of inadequate margins, enabling an accurate additional resection during the initial surgery. It is expected that implementation of paired tagging will lead to a higher number of adequate tumour resections and thereby will improve patient outcome and/or reduce adjuvant therapy and the related morbidity.

OFP-14-012

Objective intra-operative assessment of the resection margins to facilitate head and neck cancer surgery

S. Koljenovic^*, E. Barroso, T. Bakker Schut, I. ten Hove, F. van Lanschot, H. Mast, R. Smits, M. van der Kamp, A. Sewnaik, C. Meeuwis, J. Hardillo, D. Monserez, P. Ewing-Graham, R. Verdijk, F. van Kemenade, E. Wolvius, A. van Leenders, P. Caspers, R. Baatenburg de Jong, V. Noordhoek Hegt, G. Puppels

^*Erasmus MC, Clinical Pathology, Rotterdam, The Netherlands

Background & Objective: Adequate resection margins are a crucial prognostic factor in oncological surgery. For head and neck, with its complex anatomy, this is a challenge. Frozen sections have known limitations and are not suitable for bone. Our aim was to find an objective method for fast and reliable intra-operative assessment of the resection margins, including bone. For this we explored Raman spectroscopy.

Method: Experiments were performed on freshly resected specimens from 56 patients with oral cavity squamous cell carcinoma (OSCC), including those who underwent mandibulecotomy.

Results: Raman spectroscopy can discriminate OSCC from healthy soft tissue with 99% sensitivity and 92% specificity, and the border of the tumour can be determined. In addition, during mandibulectomy tumour can be detected in bone resection margins with high sensitivity (96%) and specificity (83%).

Conclusion: Our results are promising and show, for the first time, that an objective technique like Raman spectroscopy could be applied intra-operatively in OSCC surgery to evaluate resection margins, including bone. This method could facilitate adequate resection in head and neck oncological surgery.

Poster Sessions

Sunday, 9 September 2018, 09:30 - 10:30, Exhibition Hall I/II

PS-01 | Breast Pathology

PS-01-001

PDL1-expression in triple negative breast cancer: analysis of two different antibodies and their prognostic values

H. Sahin^*, U. Ugurlu, B. Gulluoglu, E. Aribal, H. Kaya

^*Marmara University Hospital, Dept. of Pathology, Istanbul, Turkey

Background & Objective: Programmed cell death protein ligand1(PDL1) expression plays an important role in inflammatory response to tumour cells. We compared two different PDL1 antibodies in triple negative breast cancer (TNBC).

Method: Ventana SP263 and BioCare RbMCAL10 antibodies were performed on 51 TNBC cases. Percentages of membranous and cytoplasmic expression were assessed in neoplastic cells (NC) and tumour-infiltrating lymphocytes (TIL). Groups and cut-off values for PDL1 expression were 0(0%), 1(1-9%), 2(10-49%), and 3(50% and above).

Results: Mean age was 52.7 (32-84). The diagnoses were medullary-like carcinoma (n=23), ductal carcinoma (n=20), metaplastic carcinoma (n=5) and basal-like carcinoma (n=3). In NC, mean PDL1 expression was 11% and 11.3% with SP263 and RbMCAL10, respectively. Mean PDL1 expression was 15.4% and 16.8% in stromal lymphocytes wtih SP263 and RbMCAL10, respectively. There was high correlation between 2 antibodies (p<0.01). PDL1 expression in NC was also corralated with PDL1 expression in TIL with both antibodies. TIL density and PDL1 expression in NC were positively associated with both antibodies. There was no statistically significant association between PDL1 expression and other prognostic parameters (age, tumour-subtype, histological grade, lymphovascular/perineural invasion, survival, and metastasis).

Conclusion: We found a strong correlation between two antibodies in TNBCs. In discordant cases, RbMCAL10 detected higher PDL1 expression generally. Between 2 antibodies, PDL1 expression in neoplastic and TIL compatments were corralated, but the relationship was stronger in the neoplastic compatment compared to TIL. The density of tumour infiltrated lymphocytes had a positive relationship with both antibodies in neoplastic compartment.

PS-01-002

Atypical lipomatous tumour of the breast – reporting a not-so-rare entity in an extraordinarily rare location

S.-A. Barbu^*, A.-C. Lisievici, T. A. Georgescu, A. Turcu, F. Pop, M. Sajin

^*SUUB, Pathology, Bucharest, Romania

Background & Objective: Atypical lipomatous tumour/well-differentiated liposarcoma (ALT/WDL) of the breast is a very rare malignant tumour accounting for less than 1% of all breast malignancies, which was first reported by Neuman in 1862. It features amplification of the 12q13-15 chromosomal segment, which includes the genes MDM2, CDK4, and HMGA2. ALT is a low-grade tumour which rarely metastasizes.

Method: We report the case of a 49-year-old female with no family history of breast cancer presenting to our clinic with a firm and imprecisely delimited tumour mass of approximately 3/1/1 cm, located in the retromammary space of the right breast.

Results: Histopathological examination revealed a neoplastic proliferation composed of lipoblasts and fusiform cells. Lipoblastic areas (representing 20% of the tumour mass) were composed of round lipoblasts with multivacuolated cytoplasm and slightly enlarged, hyperchromatic and eccentric nuclei. The fusiform cells featured vesicular nuclei and eosinophilic cytoplasm and were arranged in a solid-infiltrative pattern. Mitotic count was 8-9 mitoses/10HPF. Immunohistochemistry revealed diffuse reactivity for Bcl-2, S100, MDM2 and Vimentin, as well as negative expression of ER, PR, Mammaglobin, CK 7, h-caldesmon, CD10, CD34 and Desmin, with a Ki-67 index of 60%. Although malignant phyllodes tumour with liposarcomatous differentiation and myofibroblastoma were proposed as main differentials, the ancillary tests were highly suggestive for the diagnosis of atypical lipomatous tumour of the breast.

Conclusion: We present an extremely rare case of atypical lipomatous tumour with unusual presentation, where besides the atypical site of involvement, the lipoblastic areas represented only a small part of the tumour, causing differential diagnosis difficulties.

PS-01-003

Thymidylate synthase, Cyclin D1 and Ki-67 expression in hereditary and sporadic breast cancer

M. Riekstina^*, A. Abolins, I. Strumfa

^*Riga Stradins University, Dept. of Pathology, Latvia

Background & Objective: Thymidylate synthase (TS) is involved in DNA biosynthesis (Rose et al.,2002; Yu et al.,2005). Cyclin D1 (CycD1) regulates cell cycle and growth of estrogen-responsive tissue (Roy et al.,2006; Ezzat et al.,2012). Few studies have highlighted the immunohistochemical profile (besides molecular type) of hereditary breast cancer (HBC) regarding TS and CycD1. Aim of this study is to compare TS, CycD1 and Ki-67 expression in hereditary and sporadic breast cancer.

Method: A retrospective study included 110 cases of invasive breast cancer. Cases were classified as hereditary (45) by BRCA1/2 mutation testing in peripheral blood. Control group comprised 65 tumours. Expression of TS, CycD1 and Ki-67 was detected by immunohistochemistry and graded by percentage. Data were analyzed using descriptive statistics and Mann-Whitney U-test. p<0.05 was considered significant.

Results: In HBC, TS was expressed in 66.7% of cases, contrasting with 29.2% (p<0.001) in control group. CycD1 was expressed in 95.6% and 83.1% of HBC and control cases, respectively (p<0.001). HBC was characterized by the following mean values: CycD1, 83.5±21.9% [95% confidence interval: 76.9–90.1]; TS, 28.7±32.3% [18.9–38.4]; Ki-67, 37.8±27.8% [29.4–46.1]; control group: CycD1, 27.8±27.7% [20.9-34.6], TS, 4.5±10.4% [1.9–7.0]; Ki-67, 12.4±2.9% [11.7–13.1]. Median values in HBC was: CycD1, 91.0% (interquartile range, IQR:19.0); TS, 20.0% (IQR:50.0); Ki-67, 32.0% (IQR:51.0); in controls: CycD1, 20.0% (IQR:37.5); TS, 0.0% (IQR:6.0); Ki-67 12.0% (IQR:0.0).

Conclusion: HBC is characterized by distinctive overexpression of TS, CycD1 and Ki-67 indicating differences in cell proliferation and DNA synthesis. These markers can add informative value in HBC evaluation.

PS-01-004

Malignant adenomyoepithelioma with chondrosarcoma: a case report and review of the literature

D. I. Arslan Kahraman^*, A. Poyraz, G. Esendagli

^*Gazi University Medical School, Pathology, Ankara, Turkey

Background & Objective: Malignant adenomyoepithelioma is a rare biphasic tumour with neoplastic epithelial and myoepithelial cells. We aimed to present this rare case with macroscopic and microscopic features.

Method: The case we reported here was a 67 years-old woman who had a mass in her right breast. On the PET-CT scan for staging, there was a pathologically increased 18F-FDG uptake in the subareolar area of the right breast. Patient underwent right modified radical mastectomy. The diagnosis was made by macroscopic, microscopic and immunohistochemical studies.

Results: Macroscopically, there was a white-greyish tumour mass in the subareolar region with irregular borders and focal hemorrhagic areas. Microscopically, neoplastic lesion composed of epithelial and myoepithelial cells, a focal pleomorphic adenoma-like area and a chondroid area with an atypical tripolar mitosis compatible with chondrosarcoma. Myoepithelial cells had focal necrosis and increased mitotic activitiy. İmmunohistochemically, neoplastic myoepithelial cells were diffusely nuclear positive with p63 and focally positive with SMM, SMA, calponin, cytokeratin-19 and cytokeratin 5/6. Neoplastic epithelial cells were diffusely positive with cytokeratin-19 and cytokeratin-7 and focally positive with cytokeratin-5/6. There was a strong nuclear positivity in the area of chondrosarcoma and focal positivity in some myoepithelial cells with S-100 staining. Estrogen reseptor was very rarely nuclear positive in tumoural cells. GATA-3, Chromogranin-A, Synaptophysin and p40 were negative.

Conclusion: After reviewing the English literature, to our knowledge, this is the first case of malignant adenomyoepithelioma with chonrosarcoma. We presented a rare case and review of the literature with malignant adenomyoepithelioma.

PS-01-005

Correlation of changes of estrogen receptor and progesterone receptor expression levels in locoregional metastases of breast cancer comparing with primary tumour

K. Konyshev^*, S. Sazonov

^*Institute of Medical Cell Tech, Ural State Medical University, Ekaterinburg, Russia

Background & Objective: Discordance of biomarker expression in primary tumour and metastases is the possible reason of insufficient effectiveness of the antitumour therapy. Research objective: to evaluate correlation of changes of estrogen receptor (ER) and progesterone receptor (PR) expression in locoregional metastases of breast cancer compared with primary tumour.

Method: Postoperative samples of primary tumour and metastatically affected lymph nodes of 104 patients with invasive breast carcinoma of no special type without neoadjuvant therapy were studied immunohistochemically with monoclonal anti-ER and anti-PR antibodies (clones 1D5 and PgR-636). Staining results were evaluated using Allred score. Spearmen’s rank correlation coefficient was calculated for differences of ER and PR expression levels between metastatic and primary tumours.

Results: ER expression levels in metastases and primary tumours were different in 67 of 104 cases (64,4%, 95% CI 54,4-73,4%), PR expression levels – in 64 of 104 cases (61,5%, 95% CI 51,5-70,8%). Correlation coefficient of ER and PR expression level differences between metastasis and primary tumour was 0,49 (p<0,001) for all cases. Analyzed in groups, formed according to primary tumour ER expression level (first – 0 and 2, second – 3-6, third – 7-8 Allred scoring points) correlation coefficients were 0,24 (p=0,19) in first, 0,67 (p<0,001) in second and 0,19 (p=0,32) in third groups.

Conclusion: Changes of ER and PR expression levels in locoregional metastases compared with primary tumour of breast cancer are correlated. Statistically significant correlation was indicated in the whole sample (weak correlation) and in the group with intermediate ER expression level in primary tumour (intermediate correlation).

PS-01-006

Paget breast cancer immunoprofile as Toker's cells: a case report

G. Ristovski^*, V. Stojkovski, D. Bajdevska, P. Zdravkovski, S. Komina, B. Krsteska, S. Kostadinova-Kunovska, R. Jovanovik, B. Ilievski, L. Spasevska, G. Petrushevska, V. Janevska

^*Institute of Pathology, Skopje, Republic of Macedonia

Background & Objective: Paget's disease or Paget breast cancer is a rare and unusual breast cancer. The appearance of the disease may be associated with invasive or noninvasive tumour mass and rarely without an underlying neoplasm. The aim of this paper is to present a case of Paget’s carcinoma without an underlying carcinoma (PCWUC), arising from Toker's cells.

Method: The patient was 70-years old woman with ulcerative and crusted changes of the nipple and areola. We examined a large number of sections taken from biopsy and surgical specimen of the nipple, areola and underlying breast tissue. All slices were processed and stained with standard procedures (haematoxylin–eosin) and immunohistochemical technique.

Results: Epidermis and distal lactiferous channels were infiltrated with Paget cells resembling atypical neoplastic altered Toker's cells. Using immunohistochemistry, we found a clear demarcation between normal epithelial cells from malignant cells infiltrate. Cytokeratin 7 was positive only in tumour cells, but high molecular and low molecular weight cytokeratins were only positive in normal epithelial cells. Underlying breast tissue did not contain any tumour cells.

Conclusion: The same immunoprofile of Toker's cells and PCWUC cells suggests a common histogenesis.

PS-01-007

Quality assurance of Ki-67 proliferative index measurement in breast cancer reporting

B. Dessauvagie^*, S. McLaren, R. Jeyathevan, M. Wang, B. Allanson, A. Ireland, A. Kang, K. Meehan, C. Thomas, C. Robinson, M. Combrinck, J. Harvey, G. Sterrett

^*PathWest Laboratory Medicine, Anatomical Pathology, Murdoch, Australia

Background & Objective: Ki-67 has prognostic and predictive value in invasive breast carcinoma (IBC), but clinical uptake is hampered by suboptimal accuracy, reproducibility and standardisation. Published guidelines have addressed standardisation of pre-analytical and analytical factors, however, the practicalities of ongoing monitoring Ki-67 quality have not been discussed. We aimed to evaluate the quality of the established digital Ki-67 IBC reporting practice at our tertiary institution.

Method: In the four years since initial validation work, we completed a series of internal and external quality assurance (QA) projects. For internal QA we undertook an interoberver agreement study of the four pathologists involved in Ki-67 reporting, an interlaboratory agreement study across separate sites reporting Ki-67 and audited the year-to-year Ki-67 values. External QA was investigated by comparison of our Ki-67 data against published datasets.

Results: We demonstrated excellent concordance (R=0.91-0.97) and good agreement (K=0.76-0.96) between pathologists and excellent concordance (R=0.94) and a very good agreement (K=0.80) between laboratory sites. There was no significant difference in Ki-67 data from year-to-year, which demonstrated expected associations with clinico-pathological parameters. Descriptive Ki-67 statistics were comparable to those of Ki-67 datasets reported in other studies and our data separated into similarly proportioned ‘high’/‘low’ groups when dichotomised as per their protocols.

Conclusion: Our studies provide evidence of adequate internal and external QA for our digital Ki-67 IBC reporting service. Given the absence of a formal breast Ki-67 QA program, our approach could be emulated as a framework for Ki-67 QA in IBC.

PS-01-008

Comparative analysis of peritoneal carcinomatosis in patients with a history of breast cancer: breast cancer metastasis versus second primary tubo-ovarian and peritoneal cancer

K.-Y. Na^*, S. Lee, H.-S. Kim

^*Severance Hospital, Dept. of Pathology, Seoul, Republic of Korea

Background & Objective: Causes of peritoneal carcinomatosis (PC) in patients with a history of breast carcinoma include both metastatic breast carcinoma (MBC) and primary peritoneal/ovarian carcinoma (PPOC). The origin of PC is important to determine the appropriate treatment strategy. Cytological examination of the peritoneal fluid (PF), which may be the first diagnostic approach to PC, is of distinct value in confirming the presence of malignant cells and determining the origin of PC.

Method: We analyzed the clinicopathological and cytomorphological characteristics of 33 patients with a history of breast carcinoma whose PF cytology contained malignant cells. Cases showing positive immunoreactivity for PAX8 and WT1, and a lack of GATA3 expression were considered as PPOC.

Results: Sixteen developed PC caused by PPOC. PPOC patients were characterized by early-stage primary breast carcinoma, absence of nonperitoneal MBC before the detection of PC, and normal serum levels of CEA and CA15-3. Fourteen PPOC patients had pathogenic germline BRCA mutations. Cytological examination revealed that most of the PPOC cases had a dominant papillary arrangement of the tumour cells with severe nuclear pleomorphism, occasional bizarre nuclei, and atypical mitotic figures. Patients with PPOC who underwent cytoreductive surgery had a significantly longer survival time compared to those who did not, or MBC patients.

Conclusion: In patients with a history of breast carcinoma presenting with PC, the presence of early-stage primary breast carcinoma, no prior nonperitoneal MBC, and a dominant papillary cellular arrangement pattern in the PF cytology were independent predictors of PPOC. Cytoreductive surgery significantly improved survival for patients with PPOC.

PS-01-009

Breast implant capsule-associated pathology: from “common” to “rare” to “unique”

E. Resetkova ^*

^*MDACC, Pathology, Houston, USA

Background & Objective: The use of breast implants (BIs) for augmentation has become commonplace. It is believed that BIs could infrequently be associated with haematologic malignancies but they do not increase the risk of conventional mammary carcinoma.

Method: Cases: Common – Silicone mastitis. Rare – BI-associated anaplastic large cell lymphoma (BI-ALCL) with unusual clinical presentation and BI associated mammary fibromatosis. Unique – Metaplastic sarcomatoid squamous cell carcinoma.

Results: 77-year-old woman with silicone mastitis due to free liquid silicone injection into breasts for augmentation which caused breast deformities and pain. 69-year-old woman diagnosed with BI-ALCL who had a history of bilateral mastectomies with textured saline implant reconstruction. Initial skin breast biopsy was diagnostic of ALCL and axillary lymph node was positive for CD30-positive lymphoma cells. 52-year-old woman with BI associated mammary fibromatosis. 41-year-old woman presented with pain and breast swelling after saline breast implant augmentation 7 years ago. Implant capsule was thickened and on excision adjacent friable mass was demonstrated. Pathology revealed metaplastic sarcomatoid squamous cell carcinoma. Subsequent MRI showed chest wall mass requiring radical modified mastectomy and chest wall resection.

Conclusion: Because of rarity and unusual clinical presentation, BI associated pathology may go under recognized. It is important to increase awareness of these unusual entities. The aggressive behavior of the tumours presented in this series underscores the importance of excluding malignancy by pathologic examination in patients with long-standing BIs who present with acute onset of unilateral breast pain, breast enlargement and delayed periprosthetic fluid collection.

PS-01-010

Higher tumour cell proliferation in breast cancer of the young

A. Svanoe^*, G. Knutsvik, K. Krüger, I. M. Stefansson, B. Davidsen, T. Aas, L. A. Akslen, E. Wik

^*Centre for Cancer Biomarkers, University of Bergen, Haukeland University Hospital, Norway

Background & Objective: Breast cancer (BC) in adolescents and young adults (AYAs; 15-49 years at diagnosis) is associated with aggressive tumour features. We aimed to investigate tumour cell proliferation markers in AYAs.

Method: The proliferation marker Ki67 was analyzed by immunohistochemistry on TMA slides of breast cancer FFPE tissue from two population-based cohorts: One AYA series (n=378) and one series of patients aged 50-69 years (n=546). mRNA microarray data from the METABRIC and TCGA cohorts (n=2283) was used to investigate gene expression signatures reflecting tumour proliferation.

Results: The AYAs demonstrated higher Ki67 levels compared to BC patients ≥ 50 years (median Ki67 10.1% and 6.8%, respectively; P<0.0005). Higher Ki67 levels were found in BC of AYAs <40 years compared to AYAs 40-49 years (median Ki67: 16.1% and 8.6%, respectively; P=0.009). High levels of Ki67 among AYAs were associated with high histologic grade, ER and PR negativity, larger tumour diameter and shorter survival (all P<0.0005). When adjusting for tumour size, histologic grade and lymph node status, Ki67 maintained independent association with prognosis in ER positive AYA cases (HR 4.8; 95% CI 1.9-12.1, P=0.001). Higher mRNA proliferation scores in the young, and associations between high scores and shorter survival, validated our results (all P<0.0005).

Conclusion: BC of the young demonstrate higher tumour cell proliferation compared to older patients. Higher levels of proliferation indicators associate with aggressive tumour features and reduced survival in AYAs and may potentially contribute to the more aggressive breast cancer seen in the young.

PS-01-012

Relationship of axillary total tumoural load (TTL) by PCR (OSNA) in early breast cancer, pathological variables and clinical outcomes

R. Tur^*, J. E. Alés-Martínez, J. Parra, M. d. Rocío Martín

^*Assistencial Complex, Pathology, Avila, Spain

Background & Objective: The study of sentinel lymph nodes (SLN) assessed by PCR (OSNA) creates a new variable, Total Tumour Load (TTL; defined as the total number of CK19 mRNA copies in all positive SLN). The latest edition of the Spanish Oncological Gynaecology Society (SEGO) Guideline (2017) proposes a complete axillary lymph node dissection (ALND) when TTL is 15,000 or more in early breast cancer. We are using OSNA to assess SLN and Z0011 criteria to complete ALND. We want to determine the correlation between TTL and pathological variables and clinical outcomes and if TTL is useful to decide complete ALND.

Method: Clinicopathological and follow up data were obtained from all patients with invasive breast cancer and SLN assessed by OSNA between 2011 and mid-year 2014.

Results: A total of 167 patients underwent SNB assessed by OSNA. 54.49% were luminal A, 25.14% luminal B, 11.9% triple negative, 4.9%, Her2 positive and 4.19% luminal B-Her2 positive. TTL was cero in 92 cases and greater in 75 cases; 40 cases higher than 15,000 copies. Only 12 cases met Z0011 criteria. 3 patients have had locoregional relapse and 5 metastatic disease. 7 have died, only two from metastatic breast cancer.

Conclusion: 1. Using Z0011 criteria, we have adequate clinical outcomes with a low rate of ALND 2. If we had based the axillary management on TTL values we would have multiplied the number of ALND by a factor of 2,4 (from 12 to 29). 3. We have observed a tendency to higher TTL in luminal phenotypes and to lower TTL in HER2 positive and triple negative subtypes.

PS-01-016

Clinical study on detection of sentinel lymph node metastasis in breast cancer by one-step RT - PCR

Y. Liu^*, J. Shang, F. Ye

^*The Fourth Hospital of Hebei, Pathology Dept., Shijiazhuang City, Hebei, Hong Kong

Background & Objective: To investigate the sensitivity and specificity of SLN detection by reverse transcription-polymerase chain reaction (RT-PCR), which quantifies the expression of mammaglobin and cytokeratin-19 genes to determine SLN status.

Method: According to the AJCC, different numbers of breast cancer T47D cell were implanted into the lymph node metastasis model by cell culture, and according to the CT value the metastasis of SLN was determined. RT-PCR was performed on odd-numbered blocks of 256 clinical SLN, and the corresponding SLN even blocks were paraffin-treated. The clinical and pathological data of the patients with metastasis and no metastasis were compared.

Results: Lymph node-negative, isolated tumour cells, micrometastasis, macroscopic metastasis, positive reference with the increase of tumour cells, RT-PCR CT value is getting smaller and smaller. This study analyzed 256 sentinel lymph nodes which are from 150 cases breast cancer patients, of which 40 SLN cases could expres human mammagloglobin and CK19, and the positive rate of the samples was 15.60%. The specificity of molecular detection of BLN (90.65%) and negative predictive value (96.04%) clearly demonstrated its reliability in guiding ALND decision-making.

Conclusion: The results of RT-PCR in detecting sentinel lymph node metastases> 0.2 mm are similar to those of permanent histology. RT-PCR has objective and rapid output advantages, which is proved to be true and reliable. Therefore, RT-PCR method can be used intraoperatively to decide whether to carry out axillary lymph node dissection.

PS-01-017

The role of T-lymphocytes in brain metastasis formation of breast cancer

R. M. Santos Moreira Pedrosa^*, B. Schrijver, M. van der Weiden, W. A. Dik, P. J.M. Leenen, J. M. Kros, D. A.M. Mustafa

^*Erasmus Medical Center, Pathology, Rotterdam, The Netherlands

Background & Objective: To develop brain metastasis, breast cancer (BC) cells need to cross the blood-brain barrier (BBB). Previously, we identified the T cell response as an important pathway in helping primary BC to develop brain metastasis. Here, we aim to identify the T cell subpopulation and their secretion factors that facilitate brain metastasis formation of BC.

Method: We FACS-sorted CD3+, CD3+/CD4+, CD3+/CD8+ and CD14+ fractions of a fresh Ficoll PBMC-isolation from whole-blood of a healthy donor. All sorted cell fractions were studied at their naïve and PMA-activated status, following co-culture with BC cells. We used our in vitro BBB model for functional studies. In addition, we studied the function of interferon gamma (IFNγ) - one of the main factors secreted by T cells. IFNγ was used to activate naïve CD3+ T cells, and to affect BC cells directly.

Results: All naïve subpopulations of T cells did not enhance the ability of BC cells to cross the BBB. PMA activation increased the trespassing of BC cells through the BBB model significantly. Remarkably, BC cells that were co-cultured with CD3+/CD8+ T cell fraction were able to trespass the BBB to a higher extent (p=0.009). BC cells that were directly treated with IFNγ were not able to trespass the BBB. However, INFγ pre-treated CD3+ T cells increased the ability of BC cells to cross the BBB (p=0.006).

Conclusion: Activated T cells, especially CD3+/CD8+ T cell subpopulation, increase the ability of BC cells to cross the BBB. Furthermore, IFNγ is an important molecule in that pathway.

PS-01-018

The prognostic value of the tumour-stroma ratio in invasive breast carcinoma

W. E. Mesker^*, K. Vangangelt, L. Tollenaar, G. van Pelt, T. Dekker, P. Kuppen, R. Tollenaar

^*Leiden University Med. Centre, Surgery, The Netherlands

Background & Objective: Complex interactions occur between cancer cells and the tumour microenvironment. A high amount of stromal cells reflects a disturbed microenvironment. The prognostic value of the tumour-stroma ratio (TSR) is confirmed by stromal disalignment, stromal lymph node invasion and changed immune status of tumours in breast cancer patients.

Method: Women with invasive breast cancer (T1-4, N1-3, M0) who underwent an axillary lymph node dissection were retrospectively selected. TSR assessment was performed on H&E stained tissue sections of primary tumours and corresponding tumour-positive lymph nodes. Stromal organization was analyzed using image analysis software. Immunohistochemical staining was performed for human leukocyte antigen (HLA) class I, HLA-E, HLA-G, regulatory T cells, natural killer cells and cytotoxic T-lymphocytes to determine the immune status.

Results: Stroma-high correlates with worse RFS (P<0.001). A significant relationship was observed between stroma consisting of organized collagen and pathological response to neoadjuvant chemotherapy (P = 0.002). Patients with primary tumour stroma-low/lymph nodes stroma-low showed strongly improved 10-year RFS rates compared to patients with primary tumour stroma-high/lymph nodes stroma-high (58% versus 8%). Ten years RFP for patients with a stroma-low tumour /high immune status profile was 87% compared to 17% of patients with a stroma-high tumour/low immune status profile (P <0 .001).

Conclusion: Determination of TSR is cheap, fast and simple to apply. Patients with a stroma-high tumour have worse outcome. Response on therapy is strongly dependent on stromal alignment. The prognostic value of the TSR can be further refined by including lymph node stromal involvement and immune status profile.

PS-01-019

Adenomyoepithelioma with carcinoma of the breast: case report with next generation sequencing

P. Williams^*, S. Reid, A. Salehi, H. Kazerouni, S. Dhesy-Thind, C. MacColl

^*McMaster University, Hamilton, Canada

Background & Objective: Adenomyoepithelioma (AME) is characterized by a proliferation of two cell populations - epithelium-lined spaces in a background of myoepithelial cells. Each of these two components has the potential for malignant transformation, resulting in a rare diagnosis of AME with carcinoma. Few case reports, and even fewer molecular studies, of AME with carcinoma have been published. One author reports a mutation of the TP53 gene in a case of AME with carcinoma.

Method: A case of AME with carcinoma is identified. Tissue has been selected for Next Generation Sequencing, with results pending.

Results: A 70 year old female presented with a three month history of a palpable, 7 cm, rapidly growing breast mass. Core biopsy showed a malignant biphasic lesion, favoured to be AME with carcinoma. Mastectomy pathology confirmed the diagnosis. Sentinel lymph node biopsy was negative and CT showed no evidence of distant metastases.

Conclusion: We report a case of AME with carcinoma. Our patient will require close clinical follow-up because of the known aggressive nature of this rare tumour and potential for metastases. Although the current role for chemotherapy in the management of AME with carcinoma is unclear, if a unique genomic signature can be established, it is potentially targetable with future therapies.

PS-01-020

PDL1 expression in triple negative breast cancer – core needle biopsy versus lumpectomy

L. Stifter^*, W. Ulrich

^*Jakob Erdheim Institut / KHR, Surgical Pathology, Vienna, Austria

Background & Objective: Recent studies have shown that PDL1 positivity was most frequently observed in the subgroup of triple negative breast cancer. The intratumoural heterogeneity of PDL1-expression in breast cancer is also addressed in previous studies. In current trials the scoring system for evaluating PDL1-status changed from TPS (tumour proportion score) to CPS (combined positive score). The aim of our study was to compare PDL1-positivity in core needle biopsies and lumpectomy or mastectomy specimen. Furthermore the big difference between the applied TPS and CPS should be demonstrated.

Method: Immunohistochemical staining for PDL-1 (Biocare CAL 10) was performed on triple negative breast cancer specimens obtained from 79 patients which had core needle biopsy or lumpectomy/mastectomy performed in the breast health care centre of KH Hietzing/Vienna. We evaluated PDL1 expression in 42 core needle biopsies and 37 lumpectomy/mastectomy specimens. At first the PDL1 expression was determined by the TPS and classified as positive if TPS ≥1%. Secondly the CPS was performed on all TNBC cases and classified as positive if CPS>1. The staining results of the core biopsies were compared with those of the lumpectomy specimen of the same patients.

Results: 20% of the samples showed a TPS ≥1% and 66% a CPS>1. There was 62% concordance between the core needle biopsies and the lumpectomies of the same patients.

Conclusion: Core needle biopsies are a valid method to evaluate PDL1 status. Compared to the TPS the CPS increases the number of patients who will receive an immune therapy.

PS-01-021

High Pregnane X Receptor (PXR) expression is associated with poor prognosis in patients with invasive breast carcinoma

S. Theocharis^*, C. Giaginis, S. Gourzi, G. Tsourouflis, E. Danas, L. Nakopoulou, P. Alexandrou

^*University of Athens, First Dept. of Pathology, Greece

Background & Objective: Pregnane X Receptor (PXR) has been involved in human malignancy, either by directly affecting carcinogenesis or by inducing drug-drug interactions and chemotherapy resistance. The present study aimed to evaluate the clinical significance of PXR expression in invasive breast carcinoma.

Method: PXR protein expression was assessed immunohistochemically on formalin fixed paraffin-embedded breast cancer tissue sections obtained from 148 patients and was statistically analyzed with clinicopathological parameters and overall and disease-free patients’ survival.

Results: PXR positivity was noted in 79 (53.4%) and high PXR expression in 48 (32.4%) out of 148 breast carcinoma cases. High PXR expression was positively associated with histological (p=0.0305) and nuclear (p=0.0112) grade and tumour cells’ proliferative rate (p=0.0051). Associations between high PXR expression and estrogen and progesterone receptor negative status were also recorded (p=0.0314 and p=0.0208, respectively). High PXR expression was associated with shorter overall survival times (log-rank test, p=0.0009). In multivariate analysis, high PXR expression was identified as an independent prognostic factor of overall patients’ survival (Cox-regression analysis, p=0.0082).

Conclusion: The present data support evidence that PXR is related to a more aggressive invasive breast carcinoma phenotype, being a strong and independent prognosticator of poor prognosis.

PS-01-022

Association of serum 25-hydroxy vitamin D level and invasive breast cancer risk among Sudanese patients: a case-control study

N. E. Husain^*, A. Suliman, I. Abderahman, S. Bedri, R. Musa, H. Osman, A. Mustafa, N. Jafar, E. Farah, A. Abdel Satir, A. Agaimy

^*Omdurman Islamic University, Dept. of Pathology, Khartoum, Sudan

Background & Objective: Although suggested by several epidemiologic and experimental studies, results regarding the role of 25 hydroxy vitamin D [25 (OH) D] in the development, progression and prognosis of breast cancer have been inconclusive. This study aimed to assess the possible association between 25 (OH) D serum levels and invasive breast cancer risk in Sudanese women.

Method: This case-control study was conducted on 333 Sudanese women (100 with newly diagnosed invasive breast cancer and 233 matched non-cancer females). Serum 25 (OH) D was measured through a competitive Electrochemiluminescence immunoassay.

Results: Age ranged from 28 to 85 years with a mean (±SD) of 48.10(±12.11) years. 76.9% of breast cancer patients and 83.5% of non-cancer women had vitamin D serum levels below 20ng/ml (deficient) (P 0.077). The correlation between vitamin D level and histologic type, clinical stage and molecular subtypes of breast cancer was not significant (P. values 0.755, 0.073 and 0.192, respectively).

Conclusion: This study showed a trend towards marginal statistical significance between serum 25 (OH) D level and invasive breast cancer risk (P=0.077) and clinical stage (P=0.073), but not with histopathological type and molecular subtypes (P. values 0.755, 0.073 and 0.192, respectively). Further studies are necessary to additionally affirm these findings.

PS-01-023

Prognostic value of ALDH1 expression between invasive ductal carcinomas containing micropapillary components and invasive ductal carcinoma, NST groups

Y. Koy^*, U. S. Tetikkurt, A. Muhammedoglu, A. Celik

^*Batman State Hospital, Pathology, Turkey

Background & Objective: In our study, immunohistochemical expression profile of ALDH1, a stem cell marker, was evaluated in invasive ductal carcinoma, NST (IDK, NST) and invasive ductal carcinomas containing micropapillary component (MPKIDK). The relationship between ALDH1 and clinical-pathological, prognostic parameters of tumours investigated.

Method: Between 2010 and 2016, 105 cases were included in the study which were evaluated as IDK, NST and MPKIDK in our laboratory. Immunohistochemically, MPKIDKs were selected based on the EMA positivity pattern. Tumours were immunostained with ALDH1 antibody. No staining in tumour cells: negative; less than 10% weak or focal staining: 1+; moderate intensity in 10-50% staining: 2+; more than 50% strong cytoplasmic staining was assessed as 3+. No staining with ALDH1 in stromal cells or staining with less than 10% was negative; more than 10% of the staining was positive.

Results: There was no significant difference between clinical-pathological, prognostic parameters, tumoural ALDH1 expression ratio and staining intensity in IDK, NST and MPKIDK groups. ALDH1 was significantly higher in Ki-67 proliferation index 3+ staining cases than the 1+ cases (p=0,048). Stromal cells showing ALDH1 staining around the peritumoural area were more intense but ALDH1 positive stromal cells showed less density in the surrounding benign ducts.

Conclusion: Elevated Ki-67 proliferation index and ALDH1 expression can be used as supporting markers for detecting potentially aggressive tumours in invasive ductal carcinomas. According to our results we suppose that ALDH1 positive stromal cells with high density in the peritumoural areas may have protective effect and stromal response against development of malignancy.

PS-01-024

Positive axillary lymph node status pre-neoadjuvant chemotherapy (NACT) is associated with a high rate of post-NACT sentinel lymph node biopsy positivity

K. Dinneen^*, C. Quinn, D. Gibbons

^*St Vincents University Hospital, Histopathology, Dublin, Ireland

Background & Objective: Pre-operative axillary lymph node (LN) assessment informs surgical treatment of the axilla in management of primary invasive breast cancer. In patients undergoing primary surgery, a positive LN predicts significant disease burden warranting progression to direct axillary node clearance (AXCL). In patients with a positive LN who subsequently receive NACT with a good radiological response, post-NACT sentinel lymph node biopsy (SNLB) is performed to assess the need for AXCL. This study investigates the correlation between pre- and post-NACT LN status, related to tumour biomarker profile.

Method: The study comprised 93 patients with a positive pre-NACT LN, assessed using ultrasound guided FNAC, who were diagnosed and treated at SVUH between 06/15-07/17. Two patients had multifocal disease. Tumour biomarker profile was 46 hormone receptor (HR)+HER2-, 37 HER2+, 12 triple negative (TN)

Results: Following post-NACT imaging, 51/93 patients (55%) had SLNB and 42/93 (45%) proceeded to direct AXCL. 33 patients who underwent direct AXCL had further nodal disease (79%). 30/51 (59%) SLNB were positive; 26 progressed to AXCL with further nodal disease in 9 (35%). Post-NACT LN positivity was associated with HR+HER2- biomarker profile (p <0.05).

Conclusion: Our findings suggest that in patients with positive pre-NACT LN FNAC, there is a high incidence of post-NACT SLNB positivity and requirement for AXCL, regardless of imaging findings. Based on current data, HR+HER2- biomarker profile is significantly associated with a higher rate of SLNB positivity, compared with HER2+ and TN tumours.

PS-01-025

Impact of decalcification on prognostic/predictive indicators in bone metastases from breast cancer. An experimental study

L. Ventura^*, E. Di Gennaro, C. Mercurio

^*San Salvatore Hospital, Division of Pathology, L’Aquila, Italy

Background & Objective: Prognostic/predictive indicators (ER, PR, Ki-67, HER2) in bone metastases from breast cancer are of paramount importance for adequate treatment decisions, but immunohistochemistry (IHC) on decalcified specimens is considered unfeasible and/or its results unreliable. Retrospective investigations found significant discrepancies between primary breast carcinoma and metastases, depending on true disease changes and pre-analytical variables as decalcification.

Method: In order to assess the reliability of IHC, a so-called experimental decalcification was performed on primary breast cancer tissue using ethylendiaminetetraacetic acid (EDTA). In 5 cases, tiny portions from primary tumours were decalcified for one hour after fixation; in 5 cases, one-hour decalcification was performed on paraffin blocks of primary tumours. Histological sections were immunostained for ER, PR, and Ki-67 using DAKO OmnisTM automated platform. HER2 status was tested by DAKO HercepTestTM. The results of the original report were used as standards.

Results: ER and PR immunostains of decalcified tumours gave results comparable to the original reports. Ki-67 appeared significantly lowered in nearly all the samples decalcified after fixation and in 1 sample undergone surface decalcification. HER2 passed from 1+ to 0 score in 1/5 samples decalcified after fixation, without variations in the remaining four and in all samples exposed to surface decalcification.

Conclusion: The percentage and intensity of immunostaining for ER, PR and HER2 is not hindered by decalcification of fixed biopsies or paraffin blocks. Ki-67 is severely effaced by decalcification after fixation, but not after paraffin decalcification. EDTA decalcification of paraffin blocks appears a reliable method to perform IHC on bone metastases from breast cancer.

PS-01-027

Oestrogen receptor antibodies and their performance in the UK National External Quality Assessment Scheme for Immunocytochemistry and In Situ Hybridisation (UK NEQAS ICC & ISH)

S. Parry^*, A. Dodson, K. Miller

^*UK NEQAS ICC & ISH, Office 127, London, United Kingdom

Background & Objective: UK NEQAS ICC & ISH conducts assessments of oestrogen receptor (ER) immunohistochemistry (IHC) at quarterly intervals. At each run, the Scheme assesses participant’s stained slides for technical quality and gathers detailed information on primary antibodies and other methodological parameters. We examined these data for assessment runs conducted between 2007 and early-2018.

Method: Data were extracted from the Scheme’s database and analysed in respect of performance of primary antibody clones and IHC staining platform suppliers.

Results: Between 2007-18, 34 ER assessments were conducted (10,321 submissions). Median number of participating laboratories at each run was 333 (range=264-368). In total, 546 laboratories participated (from 61 countries); 36% were from the UK, contributing 50% of the data-sets. In 97% of submissions, one of four primary antibody clones was used (1D5:7%; 6F11:48%; EP1:8%; SP1:34%). The mean pass-rate was 91%. For each individual clone mean pass-rate (trend, between first and last use) was: 1D5:81% (96-67%); 6F11:88% (97-94%); EP1:98% (67-100%); SP1:97% (96-100%). IHC staining platforms from 3 suppliers were represented (those used by <20% of participants excluded), Agilent-Dako:20%; Leica Biosystems:25%; Ventana:40%. Non-automated staining was used for 2% of submissions. Mean pass-rates (trend) for each was: Agilent-Dako:90% (99-94%); Leica Biosystems:89% (100-100%); Ventana:96% (100-99%); non-automated:82% (100-67%). Additional methodological analyses will be presented and 10-year performance trends will be examined.

Conclusion: Analysis of the data has shown performance differences between ER clones and IHC staining platforms.

PS-01-028

Clinical significance of EphA2, EphA4 and EphA7 expression in triple negative invasive breast carcinoma

S. Theocharis^*, I. Nikas, K. Petsouska, C. Giaginis, P. Alexandrou, E. Danas, L. Nakopoulou, G. Tsourouflis

^*University of Athens, First Dept. of Pathology, Greece

Background & Objective: Ephrin receptors (Ephs) are frequently overexpressed in a wide variety of human malignant tumours, being associated with growth, invasion, angiogenesis and metastasis. The present study aimed to evaluate the clinical significance of EphA2, EphA4 and EphA7 expression in triple negative breast carcinoma (TNBC).

Method: EphA2, EphA4 and EphA7 protein expression was assessed immunohistochemically on formalin fixed paraffin-embedded TNBC tissue sections obtained from 52 patients and was statistically analyzed with clinicopathological parameters and overall and disease-free patients’ survival.

Results: EphA2, EphA4 and EphA7 positivity was noted in 52 (100%), 27 (51.9%) and 43 (87.8%) out of 52 TNBC cases, respectively and high EphA2, EphA4 and EphA7 expression in 26 (50.0%), 25 (48.1%) and 32 (61.5%) cases, respectively. EphA2 expression was positively associated with tumour cells’ proliferative rate (p=0.0054), EphA4 expression with the presence of lymph node metastases (p=0.0444) and EphA7 with histological grade (p=0.0647). Enhanced EphA2 expression was associated with poor overall and disease-free patients’ survival at both univariate (p=0.0006 and p=0.0141, respectively) and multivariate (p=0.0041 and p=0.0232, respectively) level.

Conclusion: EphA2, EphA4 and EphA7 may be implicated in the malignant transformation of TNBC and especially EphA2 may be considered as a strong prognosticator of poor prognosis and possible treatment target.

PS-01-029

Tumour-infiltrating CD8+ lymphocytes after primary systemic therapy predict clinical outcome in patients with breast cancer

J. W. Woo^*, Y. R. Chung, M. Kim, H. J. Kim, A. N. Seo, S. Ahn, H. Y. Na, G. Y. Choe, S. Y. Park

^*SNUBH (SNUH in Bundang), Pathology, Seongnam-Si, Gyeonggi-Do, Republic of Korea

Background & Objective: Tumour-infiltrating lymphocytes(TILs) have prognostic values in breast cancers. This study was performed to investigate changes of TIL subsets after primary systemic therapy (PST) and their prognostic significance in breast cancer.

Method: 155 patients who had received anthracycline- or anthracycline and taxane-based PST and had residual disease were included. The change of intratumoural and stromal TIL subsets (CD4+, CD8+, FOXP3+ TILs) in pre- and post-PST breast cancer samples and their association with clinicopathologic features and patient survival were analyzed.

Results: Intratumoural CD4+ and CD8+ TILs increased, but stromal TILs decreased after PST. As for FOXP3+ TIL, both intratumoural and stromal TILs decreased after PST. The chemo-responsive subgroup showed the same pattern of change in CD8+ TILs as in the whole group, but the chemo-resistant subgroup did not show significant change. Survival analyses for each TIL subset and their ratios revealed that only high CD8+ TIL infiltration after PST was an independent prognostic factor for favorable survival outcome. In subgroup analysis by pre-PST CD8+ TIL status, high CD8+ TIL infiltration after PST was revealed as a favorable prognostic factor in the pre-PST high CD8+ TIL subgroup, but not in the low CD8+ subgroup. Prognostic significance of high CD8+ TIL infiltration after PST was also found in hormone receptor-positive subgroup and in the chemo-resistant subgroup.

Conclusion: This study showed that CD8+ TIL subset moves from stromal to intratumoural compartments during PST, especially in chemo-responsive tumours and that CD8+ TIL status in residual tumours after PST can serve as a useful prognostic marker in patients with breast cancer patients who receive PST.

PS-01-031

Tumour associated macrophages as potential prognostic biomarkers in breast cancer

S.-Y. Kwon^*, H.-S. Jeong, S.-H. Kang, Y.-N. Kang, M.-S. Choe, H.-R. Jung, H.-W. Lee, I.-S. Hwang, S.-P. Kim

^*Dongsan Medical Center, Dept. of Pathology, Daegu, Republic of Korea

Background & Objective: Tumour associated macrophages (TAMs) are activated macrophages with tumour progression in various cancers. They can polarize M1 or M2 types. M1 has a pro-inflammatory function and kill pathogens. Conversely, M2 shows immunosuppressive and promote tumour growth. There are various markers of TAMs. CD11c is regarded as a specific M1 marker and CD163, revealed in M2. CD68 is known as a pan-macrophage marker. We evaluated the relationship between clinicopathological parameters and the immunohistochemical expression of CD163, CD11c, and CD68 in invasive breast cancer (IBC) and the prognostic value of macrophage localization with tumour stroma (TS) and tumour nest (TN).

Method: IHC of CD68, CD11c, and CD163 was performed on TMA of 367 IBC. The number of CD68+, CD11c, or CD163+ macrophages in TN versus TS was counted. The correlations between CD68+, CD11c+, and CD163+ macrophages and the clinicopathological parameters were analyzed. Additionally, we assessed the impact of CD68+, CD11c+, and CD163+ macrophages in TS and TN on DFS and OS.

Results: Infiltration of CD68+, CD11c+, and CD163+ macrophages into TS or TN has a significant clinical relevance with positive correlation with higher histologic grade, increased Ki-67, and ER and PR negativity in TN. CD163+ macrophages in TS and TN have positive correlation of T stage. Furthermore, CD163+ macrophages in TN were an independent prognostic factor with reduced OS and DFS. Conversely CD11c+ macrophages in TS were an independent prognostic factor for improved OS and DFS.

Conclusion: TAMs in the TS is an independent predictor of tumour progression in IBC. It also can be a significant unfavorable prognostic factor and a potentially useful diagnostic and prognostic marker for IBC.

PS-01-032

Efficacy of radiotherapy after breast conserving surgery depending on the presence of tumour infiltrating lymphocytes (TILs)

A. Kovács^*, E. Werner Rönnerman, L. Hartman, M. Sjöström, D. Lundstedt, E. Holmberg, P. Malmström, M. Fernö, P. Karlsson

^*Sahlgrenska University, Clinical Pathology & Genetics, Gothenburg, Sweden

Background & Objective: To evaluate the effect of postoperative radiotherapy (RT) after breast conserving surgery depending on stromal-tumour infiltrating lymphocytes (sTILs) in the primary breast tumour.

Method: 1178 patients with breast cancer stage I and II were randomized to postoperative RT or not within the SweBCG-91RT trial. Median follow-up for ipsilateral breast tumour recurrence (IBTR) was 15.2 years. Blocks were collected from 1003 patients. Subtyping was performed with immunohistochemistry. sTILs were scored in 941 patients using haematoxylin-eosin stained full tissue sections.

Results: The sTIL score was <10% in 669/941 (71%) of all the patients. sTILs values were well balanced between the treatment arms. In a multivariable regression analysis with RT and sTILs as explaining variable and IBTR as outcome variable the hazard ratio for RT versus no RT was 0.48 (95%CI 0.34-0.66) in the low sTILs subgroup (<10%) and 0.77 (95%CI 0.54-1.11) in the high sTILs subgroup (>10%). Test for interaction between RT and sTILs did not reveal a significant interaction (p=0.19).

Conclusion: RT reduced the risk for IBTR significantly. Lower values of sTILs indicated numerically lower risk for IBTR. However, sTILs did not significantly interact with the effect of the postoperative radiotherapy.

PS-01-033

Sentinel lymph node biopsy (SLNB) versus axillary lymph node dissection (ALND) following neoadjuvant chemotherapy in women with node-positive breast cancer at diagnosis: retrospective study

M. Cattani^*, S. Calderoni, M. C. Cucchi, M. P. Foschini

^*Ospedale Bellaria Azienda USL, Anatomia Patologica, Bologna, Italy

Background & Objective: The meaning of small volume metastases in the sentinel node (SN), performed after neo-adjuvant chemotherapy is still subject of debates. Purpose of the present study is to present data from a cohort of patients, cN+ who become cN0 after NAC.

Method: Sixty-four cases cN+ (cytologically proven nodal-disease) before NAC and cN0 after NAC, received SNB. Relation between SN status and axillary dissection was examined.

Results: SNB resulted negative in 36 cases and no axillary dissection was performed. The remaining 28 cases were classified as macrometastases (8), micrometastases (15) and isolated tumoural cells (ITC)(5). Axillary dissection was performed in 20 cases. The number of cases showing further axillary involvement was: 4\\8 in cases with SN macrometastases; 4\\9 in cases with SN micrometastases and 1\\3 in cases with SN ITC. Furthermore, all nodes showed treatment effects (fibrotic areas and hyaline scars, aggregates of foamy histiocytes). For each case a comparison with histotype, grading and biological parameters (ER, PGR, Ki-67 and HER-2) was done. The lymph node final status was also correlated with the degree of tumour regression at the level of mammary neoplasia.

Conclusion: The meaning of micrometastases and ITCs is different in the neoadjuvant setting than in the adjuvant setting. When ITCs are present in the lymph-node, it cannot be considered pathological complete response (pCR). The present data indicate that small volume metastases after NAC can indicate residual axillary disease.

PS-01-034

Primary breast lymphoma. Presentation of eight cases with literature review

O. Tzaida^*, M. Kotsopoulou, N. Novkovic, G. Stanc, P. Lampropoulou, P. Repousis, A. Megalakaki, I. Nomikos

^*Metaxa Cancer Hospital, Pathology Dept., Pireaus, Greece

Background & Objective: Lymphomas rarely affect the breast, the majority being secondary. PBL accounts for 0.04%-0.5% of breast malignancies and less than 0,5% of all malignant lymphomas and about 2% of extranodal lymphomas. Recognition of breast lesions as haematolymphoid is critical to distinguish them from other entities occurring in the breast. We present eight cases PBL and we review the relative literature.

Method: Eight patients, seven women and one man, without a history of previous lymphoma, were diagnosed having PBL, during a seven years period, among 21030 breast malignancies (percentage: 0,04%). Average age was 66 years (range: 48-94). Seven patients presented with a palpable, painless mass while in one the lesion was detected by routine mammography. One patient had bilateral involvement. Breast biopsy or partial mastectomy with lymph node dissection were performed in six and two cases, respectively.

Results: On histology, tumours consisted of neoplastic cells with lymphoid morphology that tended to infiltrate around and within mammary units. Immunohistochemical analysis confirmed their B-cell lymphoid origin. Four MALT lymphomas, two DLBCL and two follicular lymphomas were diagnosed. The patient with bilateral lesion had additionally lymph node involvement. Subsequent CT scans and bone marrow biopsies showed no evidence of extra-mammary disease. All patients received a combined chemotherapy regimen. After an average 45 months follow-up period there was no recurrences.

Conclusion: PBL is a rare breast malignancy. Accurate and early diagnosis is critical to avoid unnecessary surgery and ensure access to appropriate treatment.

PS-01-035

The value of tumour infiltrating lymphocytes (TILs) for predicting response to neoadjuvant chemotherapy in breast cancer: a study in a hospital complex

A. Cordoba^*, Y. Ruiz de Azua, C. Arean, B. Aguiar, L. Nova, T. Labiano, A. Ulazia, D. Guerrero

^*Hospitalario de Navarra, Dept. of Pathology, Pamplona, Spain

Background & Objective: The link between the immune system and cancer is well known. Lymphocytes are the effector cells that mediate the immune response. The validity of the histological assessment of the tumour infiltrating lymphocytes (TILs) in cancer has been standardized by The International TILs Working group. The aim of the study was to analyze the association between TILs and the grade of response to neoadjuvant chemotherapy (NAC).

Method: The stromal TILs on haematoxylin and eosin (H&E) stained tumour sections were analyzed by light microscopy following the International TILS Working Group tutorial in 122 unselected patients. These patients were diagnosed of breast carcinoma (BC) at the Department of Pathology (Hospital Complex of Navarra) and treated with NAC between 2011 and 2017. The TILs were scored in three categories: 1-10%, 11-20% and more than 20%, and studied the association with other biomarkers and intrinsic BC subtypes.

Results: We observed a statistically significant association between TILs score >20% and the pathologic complete response (pCR) to NAC (Miller-Payne:5) (p=0.026). This association is also significant if we considered the grades 4-5 of Millar-Payne Grading System. We did not find any association between the density of TILs and no expression of ER (P=0.69), ki67 expression (p=0.19) or the HER2/triple-negative subtypes (p=0.92).

Conclusion: •BC with ≥20% of TILs is more likely to reach pCR. •The TILs assessment in needle core biopsy can predict the response to NAC and help for clinical decision. •The TILS assessment following the standardized International TILS Working Group approach is feasible in all the Departments of Pathology.

PS-01-036

Discrepancy in hormones and growth factor receptor expression in primary versus metastatic breast cancer

M. Mchedlishvili^*, N. Kekelidze, N. Chikhladze, K. Khachapuridze, K. Tsomaia

^*Institute of Morphology, Clinical Pathology, Tbilisi, Georgian

Background & Objective: Breast cancer can metastasize anywhere in body. Many researches show that the molecular profile may change when cancer metastasize. But there exist few data about metastases to the skin worldwide. This study aims to evaluate retrospectively discordance of hormonal receptor status among primary and metastatic (recurrence) breast cancer, particularly in skin. Our study is the first in Georgian population.

Method: We analyzed medical records of 109 women with breast cancer relapse who developed recurrence in lung (32), liver (27), skin (29) and bone (21).

Results: We revealed that all 29 cases with positive ER status remained positivity in skin mts. PR-negative status was stable in 7 cases; 0 case was changed from negative to positive. 12 cases changed from PR-positive to PR-negative and 10 case remained stable positive status; Negative HER2 status was staid stable in 17 cases and 6 cases was changed from negative to positive, 0 case lost HER2 receptor and 5 case staid stable positive status. We also revealed that the fastest relapse in skin was developed in 2 years and the latest recurrence in 10 years. We revealed that out of 29 patients 26 had PR/ER (+).

Conclusion: We find out also that there was no significant correlation between grade and recurrence in skin. No changes were identified in grades between primary and secondary tumour. In skin metastases most discordance revealed in PR status, where 41% of patients’ skin mts became PR-negative. HER 2 status was changed also from negative to positive (in 20%), no discordance was found in HER2 (+) status

PS-01-037

ALDH1L1 downregulation and hypermethylation in breast cancer

R. Novakovskiy^*, G. Puzanov, N. Melnikova, A. Dmitriev, A. Beniaminov

^*Engelhardt Inst. of Mol. Biol., Moscow, Russia

Background & Objective: Investigation of ALDH1L1 expression and pattern of promoter methylation in breast cancer and analysis of association of these features with clinical characteristics of the tumours.

Method: Thirty primary tumour specimens and thirty matched histologically normal tissues were obtained from patients diagnosed with stage I-III breast cancer prior to radiation or chemotherapy. Expression level of ALDH1L1 was evaluated by quantitative PCR. Treatment of the genomic DNA with sodium bisulfite and targeted high-throughput sequencing (MiSeq, Illumina) were applied to assess methylation level of ca 100 CpG sites in promoter region of the gene.

Results: Expression of ALDH1L1 was considerably suppressed in all tumour specimens: on average, more than 10-fold downregulation was observed. Hypermethylation of the gene promoter region was also revealed in the majority of breast tumours. We have demonstrated statistically significant negative correlation between average methylation level of promoter region and expression level of ALDH1L1 gene. Moreover, high-throughput bisulfite sequencing of the gene promoter allowed us to specify CpG sites, which hypermethylation was associated with gene expression. However, no significant correlation was observed between the gene expression or promoter methylation level and clinical characteristics of the tumours.

Conclusion: Strong downregulation and hypermethylation of ALDH1L1 already at early stages of breast cancer argue that suppression of ALDH1L1 is a prerequisite for malignant transformation and the gene is highly likely to be a tumour suppressor but not a suitable marker for differential diagnostics of breast tumours.

This study was financially supported by the Russian Science Foundation, grant 17-74-20064.

PS-01-038

Hormone receptor status in invasive breast carcinoma – single institution results of more than 10,000 consecutive cases

P. Drev^*, O. Blatnik, J. Blazina, J. Contreras, G. Gašljevic, M. Gjidera, B. Grcar Kuzmanov, A. Klevišar Ivancic, S. Djokic, B. Gazic

^*Institute of Oncology, Dept. of Pathology, Ljubljana, Slovenia

Background & Objective: Immunohistochemical demonstration of hormone receptors (HR) is a crucial factor for management of invasive breast carcinoma (IBC). Regular monitoring of HR assessment results is recommended, however published data on expected patterns of HR status and expression are scarce.

Method: Institutional database was searched for primary IBCs in the period 2006-2017. ER and PR were assessed immunohistochemically. IHC protocols were EQA monitored. Cut-off was 1%. Analysis was performed to obtain data (average and annual variation) on HR, ER and PR status, level of ER and PR expression (% of stained tumour cells), co-expression of ER and PR and PR expression in ER negative IBCs.

Results: 10637 consecutive IBCs were identified. 87% were HR positive, 87% ER and 76% PR. ER and PR expression was strong (>80% positive cells) in 78% and 43%, intermediate (1-80% positive cells) in 8% and 33% and negative in 14% and 24% respectively. 75% were ER+/PR+, 12% ER+/PR-, 0.5% ER-/PR+ and 13% ER-/PR-. Annual variation was minimal in all parameters. PR expression in ER negative tumours was very low (1-9% positive cells) in 71% and rarely intermediate or high.

Conclusion: 87% IBCs were HR positive, 87% ER positive and 76% PR positive. ER expression was predominantly strong or negative and rarely intermediate while PR expression was usually strong or intermediate and less frequently negative. ER-/PR+ IBC were very rare and in these PR expression was usually very low. Annual variation was minimal if methods are subjected to regular EQA monitoring.

PS-01-039

Adenomyoepithelioma and malignancy in association with adenomyoepithelioma, 4 cases from a single center

T. C. Savli^*, E. C. Kelten Talu , D. Can Trabulus , U. Gursu

^*Istanbul Tra. and Res. Hospital, Clinical Pathology, Turkey

Background & Objective: We aimed to present unusual cases; 1 adenomyoepithelioma and 2 malignancy arising from adenomyoepithelioma.

Method: Three cases diagnosed as adenomyoepithelioma (Case 1), low grade mucoepidermoid carcinoma (Case 2) and malignant adenomyoepithelioma (Case 3) were re-evaluated, retrospectively.

Results: Case 1: Tumor showed well-defined borders and composed of both epithelial and myoepithelial cell proliferation in a tubular growth patern. Although this case, had a history of adenomyoepithelioma 9 years ago from another hospital, no necrosis, mitosis, cytonuclear atypia were detected in current lesion. Case 2: Tumor showed lobulated borders. Microscopically, while some of these lobules correlated with adenomyoepithelioma with papillary growth pattern, the rest of the tumor showed solid-cribriform proliferation of different type of epitelial cells. These cells composed of intermediate, epidermoid type cells and sparsely mucinous cells with low grade cytonuclear features. Ki-67: 10-15% Case 3: Tumor displayed extensively cystic-hemorrhagic areas with expansile borders. Microscopically, tumor showed several types of growth patterns and epithelial cell shapes. While some areas composed of solid proliferation of polygonal cells with clear/eosinophilic cytoplasm, other areas composed of cribriform proliferation or irregular nests including plasmocytoid type cells within the myxoid matrix. Osteoid/osteochondroid formations were present. Necrosis and 12 mitosis/10HPF were detected. Some of papillary type of benign adenomyoepithelioma foci were noted at the periphery of the tumor. No accompanying in situ/invasive carcinoma were determined. Ki- 67: 35%. Metastasis to axillary lymph nodes and/or distant organs were not determined in last 2 malignant cases.

Conclusion: Because of the rarity of these lesions, we found them worthful to present.

PS-01-040

Tumour-infiltrating lymphocytes (TILs) as a predictor of response to neadjuvant chemotherapy in breast cancer

L. Hernandez Leon^*, G. Tapia Melendo, E. Castellà Fernández, T. V. Sanhueza, R. Marginet Flinch, M. Martín Céspedes, V. Quiroga García, M. Margelí Vila

^*Dept. of Pathology, HUGTiP, Institut Català de la Salut, Badalona, Spain

Background & Objective: Breast cancer is a heterogeneous disease with different molecular subtypes. The HER2-positive (HER2+) and the triple-negative (TN) subtypes have shown improved survival when neoadjuvant therapy results in a complete pathologic response (CRp). Since there is a link between the abundance of TILs and the occurrence of CRp, TILs evaluation is becoming an important aspect of routine histopathologic examination. Our aim is to explore the correlation between TILs presence and CRp achievement in our cases.

Method: This study has included patients with invasive ductal carcinoma diagnosed in our centre in 2017 and treated with chemotherapy. Following literature recommendations, TILs were examined in tumour stroma using haematoxylin-eosin (HE)-stained slides and the findings were expressed as the percentage of tumour stromal area occupied by mononuclear inflammatory cells/total tumour stromal area. The correlation between TILs and CRp was analysed with the IMB-SPSS programme.

Results: Fifteen patients (9 HER2+ and 6 TN) have been studied. Sixty per cent of patients (66% HER2+ and 50% TN cases) achieved CRp, while the rest showed a partial response. Of the cases with abundant TILs (≥30, n=6) 83% showed CRp, whereas CRp was observed in 55% of instances with few TILs (<30, n=9). These differences didn’t reach statistical significance (p=0.28), probably due to the limited number of cases studied.

Conclusion: Our preliminary results indicate that a high TILs percentage is associated with a positive CRp. TILs evaluation, which can be done on HE-slides without recourse to immunohistochemestry, is thus emerging as a useful predictor of response to neoadjuvant chemotherapy in breast cancer.

PS-01-041

Lymphoepithelioma-like breast carcinoma. Report of a case

E. Pigadioti^*, N. Koufopoulos, D. Dimas, E. Kanari, I. Missitzis, L. Khaldi

^*Dept. of Pathology, Anticancer Oncologic Hospital, “St. Savvas”, Athens, Greece

Background & Objective: We present a case of lymphoepithelioma-like carcinoma of the breast (LELC-B) a very rare primary breast carcinoma with 33 cases reported in the English literature.

Method: A 57-year old patient was admitted due to palpable lymphadenopathy of the left axilla. On clinical examination a small palpable lump of the left breast was found followed closely by FNA cytology that was positive for malignancy.

Results: Grossly, the tumour was relatively well circumscribed with hard consistency measuring 22 mm. Microscopically on low power examination it was multilobulated with lobules divided by fibrous septa. Higher power examination revealed small tumour islands and trabeculae consisting of highly atypical cells, with abundant eosinophilic cytoplasm embedded in a lymphocyte rich stroma which surrounded and intermingled with the tumour cells often obscuring their epithelial nature. Metastatic disease was found on 8 lymph nodes. Immunohistochemical study was positive in the tumour cells for the epithelial markers AE-1/AE-3, Cytokeratin 8/18 and Cytokeratin-7 and negative for Cytokeratin-20, CD3, CD20, CD15, CD30 and CD79a confirming the epithelial nature of the neoplasm. E-Cadherin was positive whereas ER, PR, C-ERB-2 and CD117 were negative, with Ki-67 staining 80% of the tumour nuclei. Epstein-Barr virus was not detected by in situ hybridization. Type 16 HPV was detected by PCR and in situ hybridization.

Conclusion: The diagnosis of LELC-B was made. The patient received adjuvant chemotherapy and RT. Forty-eight months later there is no evidence of recurrence or metastasis. LELC-B is a rare primary breast carcinoma with unique morphology, excellent response to treatment and favorable outcome.

PS-01-042

The diagnostic value of liquid-based cytology in thyroid fine needle aspiration: an institutional experience

C. Sadullahoglu^*, H. Tosun Yildirim, S. Yildirim, I. Atalay Karaçay, D. Nergiz, A. Sezgin Alikanoglu, D. Süren, C. Sezer

^*Antalya Education and Training, Pathology, Turkey

Background & Objective: Fine needle aspiration (FNA) is often the first step procedure because it is easy, reliable and economical to evaluate thyroid gland nodules. Liquid based cytology (LBC) is a method developed to evaluate gynaecologic cytologic specimens and it is now applied to cytologic materials obtained from thyroid FNA. İn our study, we aimed to determine the diagnostic value of LBC method in assessment of thyroid nodules.

Method: Between 2014 and 2017, FNA biopsy was performed on the thyroid node of 7387 patients in the presence of ultrasonography. Diagnoses of the specimens were made according to the Bethesda System for Reporting Thyroid Cytopathology (2010). Gathered during a period of 4 years, 581 cases with surgical resection were included. Sensitivity, specificity, accuracy were calculated.

Results: A total of 581 histologically confirmed cases, 16.9% (98/581) were male and 83.1% (483/581) were female. The risk of malignancy of cytology category was calculated 3.6 % of nondiagnostic,1.6 % of benign cytology, 12.2% of atypia of undetermined significance/follicular lesion of undetermined significance, 16.4% of follicular neoplasm/suspicious for a follicular neoplasm, 74.3% of suspicious for malignancy cytology and 100% of malignancy cytology. The specificity of thyroid fine needle aspiration biopsy was 100% and sensitivity was 83.3%. Diagnostic accuracy was 98.4%. False positivity was not observed. False negativity rate of cases was 0.9%.

Conclusion: LBC may be an indispensable cytology method in the evaluation of thyroid nodules because it is particularly suitable for use of ancillary methods such as immunohistochemistry and molecular assays.

PS-01-043

Acinic cell carcinoma of the breast associated with high grade ductal carcinoma: a case report

J. Jiménez Almonacid^*, J. L. García Pérez, M. d. la Paloma Arribas Granado, M. Blanco Bellas, L. Hernández Sánchez

^*Hospital 12 de Octubre, Pathology, Madrid, Spain

Background & Objective: Acinic cell carcinoma (AcCC) of the breast is a rare, special type of breast carcinoma that shows morphologic overlap with those of the salivary glands. AcCC of the breast has morphological features similar to microglandular adenosis, and as Rosen has stated and recent molecular studies support, AcCC is in fact “invasive carcinoma with acinic cell differentiation arising in microglandular adenosis.” In the current WHO classification, it is recognised as a rare type of triple-negative breast carcinoma. One third of reported cases have been associated with ductal carcinoma NOS, usually poorly differentiated triple-negative.

Method: We present a 60-year old patient who in a first needle core biopsy was diagnosed with high grade ductal carcinoma NOS, triple-negative, and with features that were interpreted as carcinoma involving microglandular adenosis on the periphery. A second needle core biopsy from microcalcifications adjacent to the main mass showed only AcCC carcinoma, also triple-negative. The patient recieved neoadjuvant chemotherapy and the posterior surgery showed minimum residual high-grade carcinoma, and more extensive residual AcCC. The sentinel node biopsy was negative.

Results: This case presents a wide morphologic spectrum, from microglandular adenosis to high grade poorly differentiated carcinoma. The interest is not only academic.

Conclusion: The recognition of this entity is important to avoid interpreting areas of microglandular-like adenosis as benign in a well-differentiated AcCC, both in a needle biopsy and in surgical margins.

PS-01-045

Primary mucinous cystadenocarcinoma of the breast: report of a rare case

E. Botsfari^*, N. Vladika, S. Barbanis, D. Gerasimidou, B. Christoforidou, E. Triantafillidou, R. Iosiphidou, P. Xirou

^*Theagenio Cancer Hospital, Pathology Laboratory, Thessaloniki, Greece

Background & Objective: Primary mucinous cystadenocarcinoma of the breast is an extremely rare entity and, to the best of our knowledge, only a few isolated cases have been reported in the literature. It is defined as a cystic tumour, composed of tall, columnar cells with abundant intracytoplasmic mucin and basally located bland nuclei.

Method: Our patient, a 59-year-old woman, presented with a mass in the right breast, measuring 0,9 cm in maximum diameter. Lumpectomy and sentinel lymph node biopsy were performed.

Results: Macroscopically, the neoplasm was well-circumscribed, solid and cystic, grey to white and was partially filled with mucoid material. Histological features were consistent with mucinous cystadenocarcinoma of the breast. Immunohistochemically, the tumour was negative for estrogen and progesterone receptors and HER2, whereas the Ki-67 proliferative index was 15%. The 3 sentinel lymph nodes were negative.

Conclusion: Primary mucinous cystadenocarcinoma of the breast is an extremely rare entity. Although in the 2003 WHO classification of breast tumours it was classified as a variant of mucin producing carcinomas, the term was abandoned, due to its rarity, in the latest WHO classification. The tumour usually occurs in older female patients, displays unique pathological features resembling an ovarian mucinous neoplasm and despite its usual triple negative immunoprofile seems to have a favorable prognosis after complete resection. A thorough clinicopathological correlation is necessary in order to differentiate primary mucinous cystadenocarcinoma of the breast from metastatic mucinous neoplasms originating from distant organs, mainly ovaries and pancreas.

PS-01-046

Comparison of immunohistochemical markers before and after neoadjuvant chemotherapy in breast cancer and their use as predictor od response

I. Jovanic^*, Z. Milovanovic, O. Zivkovic, N. Medic Milijic

^*Institute for Oncology and Rad, Dept. of Pathology, Belgrade, Serbia

Background & Objective: Changes in tumour markers between biopsies performed before and after neoadjuvant chemotherapy (NAC) are controversial. The aim of this study is to compare immunohistochemical (IHC) expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (Her-2) in breast cancer before and after treatment and to correlate the expression of tumour markers with response to NAC.

Method: Retrospectively analysis of 132 patients with locally advanced breast carcinoma diagnosed on core needle biopsies and surgical specimens was performed. IHC staining for ER, PR, Her-2 were available before and after NAC.

Results: Pre-chemotherapy IHC revealed 96 (72,73%) ER+, 80 (60,61%) PR+ and 39 (29,55%) Her-2+ cases. Nine (8,04%) ER+, thirteen (11,61%) PR+ and four (3,57%) Her-2+ patients lost positivity after NAC. Initially two (1,79%) ER-, eight (7,14%) PR- and three (2,68%) Her-2- tumours were positive after NAC. Patients with Her-2 positive and PR negative tumours before NAC demonstrate significantly higher pathological complete response.

Conclusion: No significant changes were seen in steroid receptors and Her-2 status before and after NAC but retesting of these markers in residual tumour shoud be considered to improve future tailored adjuvant therapies. The predictive factors of the pathological complete tumour response to therapy are the negative status of PR and Her-2 positive status.

PS-01-047

Prolactin and circulating vitamin D levels as risk factors for benign breast tumour

E. Valeeva^*, I. Garifullova, O. Kravtsova, N. Akberova, L. Maltseva

^*Kazan Federal University, Institute of Fundamental Medicine, Russia

Background & Objective: Recent studies showed that increased prolactin (PRL) level and vitamin D (VD) deficiency may play a certain role in breast cancer. To evaluate the role of prolactin and circulating vitamin D level in patients with benign breast tumours (BBT).

Method: 134 patients with fibrocystic mastopathy including 92 women with a diffuse form of mastopathy (DFM) and 42 patients with fibroadenoma (FA) and 134 healthy women were examined. All women underwent a visual examination, ultrasound diagnostics of mammary glands, digital mammography (under 40 years). Prolactin and VD levels were measured by ELISA. Statistical analysis done with SPSS Statistics v.20.

Results: More than half of women with DFM (59.7%) have a VD deficit compared to healthy women (7.3%). BBT patients characterized by lowering VD level (17.8±0.23 ng/ml and 20.50±0.37 ng/ml in DFM and FA respectively and 27.35±0.16 ng/ml (p-value <0.001). Furthermore, we found that in the VD deficiency mean PRL level was much higher compared to a group with normal VD supply (289.4 mU/l and 232.2 mU/l respectively). Significant negative correlation between PRL and VD was found only in DFM patients (r= -0.2106, p = 0.026).

Conclusion: Patients with DFM are characterized by low VD availability and by the highest values of prolactin which serves as an independent marker for breast cancer. Thus, correction of VD deficiency in patients with DMS can be an effective means of primary prevention of breast cancer.

This study was supported by Program of Competitive Growth of KFU.

PS-01-048

Malignant phylodes tumour with rhabdoid and chondroid differentiation in a patient with Hashimoto thyroiditis

R. A. Cioca^*, P. J. Martinez Murillo, F. G. Gutierrez, P. A. Rodríguez Miñon, I. Marin

^*Dept. of Pathology, CF Clinical Hospital, Giroc, Romania

Background & Objective: Malignant phyllodes tumours are rare entities, accounting for 0.18% of all breast tumours. The microscopic features of these tumours may occasionally include heterologous sarcomatous elements, however rhabdoid differentiation is an exceptional finding.

Method: A 49-year-old woman presented to the Emergency Department with a 6-months history of rapidly growing ulcerated left breast mass. Ultrasonography of the left breast identified a dense large lobulated mass measuring 12x10 cm, accompanied by lymphadenopathy of the left axilla. A diagnosis of high grade sarcoma with myoid immunophenotype was established on core needle biopsy. In addition, PET-CT examination revealed a solitary nodule of the left thyroid lobe (9 mm), leading to the suspicion of primary breast tumour with metastases in lymph nodes and thyroid. The patient underwent mastectomy and hemithyroidectomy.

Results: On gross examination, the thyroid showed a whitish, well delimitated nodule (1 cm), which on microscopic examination prove to be Hashimoto thyroiditis. The mastectomy specimen revealed multiple subcutaneous nodules with ulceration, with nipple and areola involvement. On cut section, the tumour (17x13x11.5 cm) was multinodular delineated by fibrous septs, containing myxoid, cystic and necrotic areas. The microscopic appearance was of a malignant stromal proliferation with chondroid and rhabdoid features, and with occasionally leaf-like projections. Axillary lymph node showed only reactive changes. Based on histological examination and in correlation with immunohistochemistry, the final diagnosis was malignant phyllodes tumour with chondroid and rhabdoid differentiation.

Conclusion: We described a rare case of malignant phyllodes tumour with uncommon histological and clinical presentation.

Sunday, 9 September 2018, 09:30 - 10:30, Exhibition Hall I/II

PS-02 | Cytopathology

PS-02-001

Can Survivin, IMP3 and GLUT-1 be helpful in the differential diagnosis of peritoneal effusion cytology?

A. Sadioglu^*, F. P. Uyar Gocun, A. Armutlu, N. Ak, C. Taskiran, O. Erdem

^*Gazi University, Faculty of Medicine, Dept. of Pathology, Ankara, Turkey

Background & Objective: The morphological differential diagnosis between malignant epithelial tumours and reactive mesothelial hyperplasia can be extremely challenging. The aim of this study is to determine whether there is a difference in the human insulin-like growth factor II mRNA binding protein 3 (IMP3), glucose transporter 1 (GLUT-1) and survivin staining between invasive malignant epithelial tumour cells and reactive mesothelial hyperplasia.

Method: We evaluated the staining of these markers on tissue microarray blocks prepared from cell blocks of 37 malignant and 17 benign peritoneal effusions.

Results: Nuclear survivin staining was observed in 56,8% (21 cases) of malignant cases and 16,7% (3 cases) of benign cases (P=0.013) where as cytoplasmic survivin staining was positive in 100% (37 cases) of malignant and %94,1 (16 cases) of benign cases (P=1.0). Strong GLUT-1 staining was seen in 31,4% (11 cases) of malignant cases, where as in only 5,6% (1 case) of benign cases (P=0.041). Positive staining for IMP-3 was observed in 27,0% (10 cases) of malignant and 50% (9 cases) of benign cases (P=0.168).

Conclusion: Nuclear survivin positivity and strong GLUT1 staining in malignant cases are potentially useful markers in differential diagnosis of malignant epithelial cells and reactive mesothelial hyperplasia. IMP3 staining has no significant difference between malignant and benign cases.

PS-02-003

How does knowledge of hpv status affect pathologists' final cytologic diagnosis?

I. Erbarut Seven^*, M. H. Toper, F. Eren

^*Marmara University, Pathology, Istanbul, Turkey

Background & Objective: Human papilloma virus (HPV) testing is commonly used as an adjunct to cytology for cervical cancer screening. Our aim is to find out if knowledge of HPV status has any affect on cytologic diagnosis.

Method: The cytology results of 27014 women with median age of 40 who had cervical screening between 2012 and 2017 were reviewed. Patients were evaluated with co-test (PAP smear+HPV test) after May 2015. Cervical cytology results before co-test period (n: 16254) were compared with the co-test period in which HPV status was known to the pathologist as a second part of this study, random 50 cases of cervical cytology were evaluated twice (blinded and unblinded to HPV status) independently by two (senior and inexperienced). pathologists.

Results: Overall epithelial cell abnormality diagnosis had increased from 1.3% to 4% after the start of co-testing. The difference was most prominent in LSIL (from 0.2 % to 1.7%) (p, <0.05). ASC/SIL ratio decreased from 2 to 0.79 with HPV co-testing. For the 50 cases reviewed by 2 pathologists, ASC/SIL ratio decreased from 0,67 to 0,43 for senior pathologist and 1,88 to 0,73 for inexperienced pathologist after unblinded screening.

Conclusion: The interpretation of cervical cytology is relatively subjective. Our findings show that knowledge of HPV status affects desicion making and increases sensitivity. Also helps espescially less experienced pathologist to classify borderline cases.

PS-02-004

Preoperative diagnosis of poorly differentiated thyroid carcinoma by fine needle aspiration cytology

A. Borda^*, A. Nechifor-Boila, A. Zahan, E. Szasz, E. Dee

^*University of Medicine, Histology, Tirgu Mures, Romania

Background & Objective: Poorly differentiated thyroid carcinoma (PDTC) is a rare but aggressive thyroid malignancy. Due to its aggressive nature, preoperative recognition is tremendously important for planning patient’s management. According to some experts PDTC diagnosis can be established only on histology. The aim of this study is to present three cases in which PDTC diagnosis was made on FNA (fine needle aspiration) cytology and to highlight those features which should raise suspicion of this rare condition.

Method: All three cases were males older than 55 years. Each presented at consultation for a gradually growing mass on the left/right side of the neck. One patient had a second tumour mass in the manubrium. FNA was recommended and was performed from the tumour and the bone mass.

Results: On cytology all three cases were similar: hypercellularity, no colloid, but extensive necrotic background. Cells were small and monotonous and were disposed either as individual dispersed cells or grouped in insular or trabecular arrangements. The nuclei were round/oval, with smooth contours and small-inconspicuous nucleoli; some cells had plasmacytoid appearance. The cytoplasm was ill-defined, sometimes finely granular. In all three cases a high mitotic rate was noticed. In one case typical papillary carcinoma cytology was associated with previously described aspects. The pathological examination of the surgical specimens confirmed the PDTC based on Turin criteria.

Conclusion: We have demonstrated that in some cases, PDTC diagnosis is possible in cytology as well. Three cytomorphological features were predictive for PDTC, others having limited value: monotonous appearance of the cells, necrotic background and mitosis.

PS-02-005

Comparative characteristics of neutrophil extracellular DNA formation during incubation with breast carcinoma autologous cells of different molecular-genetic subtype

A. Semenova^*, I. Dolgushin, E. Kazachkov, A. Vagenin, Y. Shishkova

^*Oncology Hospital, Cheliabinsk, Russia

Background & Objective: Depending on the initiating factor and the tumour cell properties of breast carcinoma, neutrophils are able to perform effector functions through either active phagocytosis or cytotoxic action, including the formation of neutrophil extracellular traps.

Method: 20 females of each group with breast cancer: luminal type A, luminal type B HER2 positive or HER2 negative, HER2 positive nonluminal type, triple negative type. Pure fractions of neutrophils were incubated with tumour cells at 37° C to assess the neutrophils functional activity. Their ability to form extracellular networks served as an indicator of neutrophils functional activity.

Results: The study revealed that during incubation of tumour cells of the luminal type A breast carcinomas, the number of extracellular DNA networks formed by them predominated over those in the carcinoma group of luminal type B HER2-negative, but there was significantly less aggressive forms of nonluminal carcinomas (triple negative type). Thus, all breast cancers tumour cells of any molecular-genetic type were activating cells, but the cells of clinically more aggressive forms showed the maximum values of the studied indicator.

Conclusion: Having low expression on receptor cells to progesterone (luminal type B, HER2 positive), the presence of HER2 overexpression (triple negative type, nonluminal), and the approximation to basal cell differentiation (triple negative type) demonstrates a much more pronounced ability to activation of neutrophils.

PS-02-006

Tall cell variant of papillary thyroid carcinoma: report of a case with tall cell variant clues in thryroid fine needle aspiration cytology

M. Benozene^*, B. Bouchindhomme, R. Caiazzo, W. Karrouz-Ribeiro, E. Leteurtre

^*CHRU Lille, Centre Biologie et Pathologie, France

Background & Objective: The thyroid fine needle aspiration cytology (FNAC) has proven that it was an important tool to characterise thyroid nodules, mostly to discriminate malignant (primitive or secondary) from benign lesions. The tall cell variant (TCV) of papillary thyroid carcinoma (PTC) is an important agressive subtype and usually associated with higher extrathyroid extension and distant metastasis.

Method: A 53-years-old woman presented a rapidly growing left thyroid nodule without thyroid dysfunction symptom but associated with compressive symptoms. Thyroid ultrasound was performed and showed a suspicious complex nodule measuring 8,4 cm in its largest dimension without lymphadenopathy (classified as TI-RADS 4b based on the Thyroid Imaging Reporting and Data System). CT-Scan confirmed these results.

Results: FNAC of this left thyroid nodule was performed and showed isolated or aggregated numerous atypical cells characterized by high nuclear-cytoplasmic ratio, an eosinophilic abundant cytoplasm, proeminent intranuclear pseudo inclusions and nuclear grooves. Neutrophils were the predominant background. Immunochemistry was used on the cell block section: antibodies CK19, HBME1 and PAX 8 were positives. The FNAC was reported as Bethesda VI: malignant, and the histologic diagnostic was PTC tall-cell variant of PTC.

Conclusion: The tall cell variant of PTC is rarely identified on FNAC. Utilisation of ancillary methods such as immunochemistry on cell block could help to identify the tumour as a primitive one and exclude a secondary tumour.

PS-02-007

Retrospective analyses of women with HSIL or more in a countryside city in relation to age, number and interval of cytological exams

J. C. Caldeira Xavier Jr^*, D. J. Camilo JF, A. P. Hehnes Guedes A Gardini, S. C. Garcia Pires D’ávilla, N. J. Mattar

^*Pathology Institute of Araçatu, Araçatuba, Brazil

Background & Objective: The Brazilian Cervical Cancer Screening Program recommends screening women between 25 and 69 years of age with cervical smears every 3 years, after two consecutive annual negative smears. Then, in ten years it is expected about 3 to 4 screening exams per women.

Method: This is an observational retrospective analytical study. The analyzed patients were stratified into three age groups. The number of screening exams was analyzed in a period of 10 years previously the histological diagnosis.

Results: After using the exclusion criteria, the sample consisted of 261patients. More than an half of patients were under-screened (less than 3 exams in the previous ten years). 46% of women showed interval between the two last exams before the diagnosis bigger than 3 years. Women between 20 and 24 years represented more than 10% of our population.

Conclusion: In our point of view, the popularization of 3 years interval can be dangerous because women can feel comfortable to not do the exam frequently. Since the number of patients between 20 and 24 years was not irrelevant, it is suggested a close relation between the age of first sexual intercourse and the diagnostic of HSIL or more in young patients. Then, it is questionable if in Brazil the screening should not start previously.

PS-02-008

Can liquid-based cytology help for diagnosing pleural and ascitic effusions?

M. Dardyk^*, V. Kometova, T. Kondratieva, G. Khabas, S. Pronin, L. Ashrafian

^*V. I. Kulakov RC for OGaP, Pathology, Moscow, Russia

Background & Objective: Pleural and ascitic fluid cytology is a simple and accurate diagnostic method to diverse benign and malignant processes. Tissue and organ specificity of metastatic tumour can be supposed by traditional smear cytology with Romanowsky-Giemse staining. But tumour cells being in a fluid can dramatically change its morphology. Thus, ancillary techniques (such as Immunocytochemistry, molecular testing, PCR) can help a lot. In these cases CellPrep Plus® (Biodyne) looks like the best possible method for samples preparation. CellPrep samples can be preserved for 6 months, what can lower the need of additional aspirations. Well-known methods of liquid-based cytology, such as SurePath® (BD) and ThinPrep® (Hologic), proved itself to be good in cervical cancer screening programs. Nevertheless, they are known as not an adequate method for diagnostic cytopathology, as they change cell morphology and remove background, that is essential for precise diagnose.

Method: In 2017 in our Centre 56 samples of pleural and ascitic fluids were simultaneously studied on traditional smears (with Romanowsky-Giemsa staining) and on CellPrep Plus® liquid-based cytology smears (with Papanicolaou staining). Rare or difficult diagnoses, that were proposed on routine microscopy, were verified with Immunocytochemistry markers, performed on CellPrep material with Automated staining system BenchMark Ultra Ventana – 26 cases

Results: Reports coincided in all 56 cases (100%). Among diagnoses, verified by Immunocytochemistry, were not only ovarian serous and mucinous adenocarcinoma, but also rarer diseases, such as Hepatoid ovarian carcinoma or Pancreatic ductal adenocarcinoma.

Conclusion: CellPrep Plus® data gives additional facilities for investigating pathology diversity of metastatic tumours in pleural and ascitic effusions.

PS-02-009

Role of cytology in the diagnosis of intraocular lesions: a retrospective study of 33 patients

H. Rodrigo Lara^*, A. Ballester, I. Torralba Cloquell, A. M. Quintero Duarte, M. A. Martínez Ortega, A. Forteza Valadés, S. Bonilla Hurtado, J. L. Olea Vallejo, J. F. Iglesias Alzueta, J. E. Serra Trespalle

^*Hospital U. Son Espases, Anatomia Patologica, Palma de Mallorca, Spain

Background & Objective: Intraocular cytology studies are infrequent due to the risk for serious eye complications and the dissemination of malignant cells, although complications are typically under-reported and the risk of seeding is low when small needles are used. So that, most frequently the diagnosis of intraocular lesions is done by non-invasive studies. Because of therapies are different depending of the disease, a definitive diagnosis must be done. We report our experience in intraocular cytology during the last 10 years.

Method: In a retrospective study over a 10-year period diagnostic cytology was performed on 33 patients with intraocular lesions. The specimens were obtained from fine needle aspiration (FNA) or from vitrectomy-based procedures. Flow cytometry and microbiologic analysis of samples were performed when required.

Results: Out of 33 specimens, cellularity was insufficient in 4 cases (12,1%), 19 (57,6%) were non-neoplastic (ocular amyloidosis, intraocular candidiasis and inflammatory processes), and 10 (30,3%) were neoplastic. Of those neoplastic lesions, 6 (60%) were choroidal melanoma and 4 (40%) were lymphoproliferative disorders. Only one melanoma was confirmed by enucleation, and all lymphoproliferative disorders were confirmed by flow cytometry. No complications were register after the procedure. And no evidence of malignant cells dissemination has been noticed.

Conclusion: In any suspected intraocular malignant lesion, in which enucleation is not the obvious treatment, the standards applied in the treatment should be equivalent to those in other fields of oncology and a diagnosis based on FNA or vitrectomy-based procedures must be done. However, in some cases specimen cellularity may be insufficient for diagnosis and some complications may happen.

PS-02-010

Cytologic diagnosis of noninvasive follicular thyroid neoplasm with papillary-like nuclear features and its impact on the risk of malignancy in the Bethesda system for reporting thyroid cytopathology: an institutional experience

J. W. Woo^*, M. Kim, J. E. Kim, H. J. Kim, Y. R. Chung, Y. Kwak, H. Y. Na, G. Y. Choe, S. Y. Park

^*SNUBH (SNUH in Bundang), Pathology, Seongnam-Si, Gyeonggi-Do, Republic of Korea

Background & Objective: Recently, “noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP)” has been proposed to replace “noninvasive encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC)” due to its indolent behavior. We analyzed cytologic diagnosis of NIFTP and its impact on the risk of malignancy (ROM) in the Bethesda system for reporting thyroid cytopathology (TBSRTC).

Method: This study included 5549 cases of thyroid fine needle aspiration cytology (FNAC) diagnosed between 2012-2014. Diagnostic categories based on TBSRTC were compared with final surgical diagnosis, and the ROM in each category was calculated.

Results: Of the 5549 thyroid FNAC cases, 1891 cases underwent surgical resection. At the time of final diagnosis, 1700 cases were revealed as PTC, and 25 cases as NIFTP. The cytologic diagnosis of NIFTP were non-diagnostic in 1 case (4%), benign in 5(20%), atypia of undetermined significance (AUS) in 14(56%), follicular neoplasm in 2(8%), and suspicious for malignancy in 3 cases (12%). While none of the NIFTP was diagnosed into malignant category, 8(17.8%) of 45 EFVPTCs with invasion were diagnosed as malignant in FNAC. Collectively, NIFTP/EFVPTCs were less frequently categorized as malignant compared to PTCs. Exclusion of NIFTP from malignant diagnoses resulted in a slight decrease in malignancy rates in some categories without any statistical significance.

Conclusion: The decrease in the ROM was not significant when excluding NIFTP from malignant lesions due to the low frequency of NIFTP. In thyroid FNACs, NIFTP/EFVPTCs were mostly classified into indeterminate categories. Therefore, it might be feasible to separate NIFTP/EFVPTC from PTC on FNAC to guide conservative clinical management with NIFTP/EFVPTC.

PS-02-011

Diagnostic concordance difference between endobronchial ultrasound-guided transbronchial needle aspiration cytology and needle biopsy according to lymph node station

I. A. Park^*, J. Koh, Y. K. Jeon,, D. H. Chung, B. Shim

^*Seoul National University Hospital, Dept. of Pathology, Republic of Korea

Background & Objective: Lymph node (LN) metastasis in lung cancer is important factor for patient to determine the prognosis and to decide treatment plan. Endobronchial ultrasound (EBUS) guided transbronchial needle aspiration cytology (EBUS-TBNAC) or needle biopsy (EBUS-TBNB) is one of the useful methods for predicting mediastinal LN metastasis in lung cancer patients. The purpose of this study was to evaluate the concordance between EBUS-TBNAC and EBUS-TBNB according to LN station.

Method: We compared simultaneously obtained biopsy and cytology of 639 patients over 3 years period from January 2011 to Sep 2014. We evaluated 12 sites of mediastinal and intralobar LNs. The mean number of cases per each LN station was 138.4 (3 to 411) and the large number of cases were 556 in LN4R, 479 in LN7 and 192 in LN4L in order.

Results: The EBUS-TBNAC and EBUS-TBNB diagnosis were concordant in 1046 (87.2%) and discordant in 244 (14.7%) cases. Among the location of LN which collected more than 10 cases, the most discordant site was LN4L station (20.8%, 40/192), and the least discordant site was LN12 (5%, 1/20). The incidence of insufficient sample for diagnosis of EBUS-TBNAC was lower than that of EBUS-TBNB (0.7% and 1.7%, respectively) and the most common site of insufficient sample acquisition was LN4L (2.9%, 14/192).

Conclusion: The data showed that there is a clear diagnostic rate differences according to sampling methods of biopsy and cytology, and LN station.

PS-02-012

Endoscopic ultrasound guided fine needle aspiration in pancreatic lesions: a four-year retrospective study with cytohistological correlation and use of DPC4

G. G. Yange Zambrano^*, J. Martín López, J. B. García Reyero, J. Martínez-Echevarría Gil-Delgad, M. Martino González, M. A. Revuelta Montoya, J. C. Yange Zambrano, H. G. Sarmiento Moncayo, G. A. Yange Zambrano, M. L. Cagigal Cobo

^*Hospital Universitario Marques de Valdecilla, Santander, Spain

Background & Objective: Endoscopic Ultrasound-guided Fine Needle Aspiration Cytology (EUS-FNAC) is the most common procedure to obtain cytological specimen of pancreatic lesions. Rapid-On-Site-Evaluation (ROSE) method has the potential to check the cellular sample and improve the adequacy rates of FNA cytology. DPC4 has been described as a prognostic factor in pancreatic cancer.

Method: A retrospective study was performed on the pancreatic lesions initially diagnosed by EUS-FNAC between 2014 and 2017. EUS-FNAC was performed with ROSE and different needles. In cases of pancreatic carcinomas in 2017, DPC4 was performed in a cell block or, failing that, in the Papanicolau (PAP) smears and in the surgical specimen. The result of staining and the clinical evolution were compared.

Results: In our series, 291 patients underwent EUS-FNA for suspected pancreatic lesion. We standardized the diagnoses according the PSC guidelines (Category I: 14%, II: 43%, III: 2%, IV: 8%, V: 5% y VI: 30%), evaluated the impact of the different needles used and the cell blocks obtained. We also studied 32 cases of pancreatic carcinoma from 2017; 15 men and 17 women, mean age was 68.71 years, category I: 1, II: 3, III: 1, V: 2 and VI: 25; in which DPC4 was performed in 28 PAP, 24 blocks and 9 surgical pieces.

Conclusion: EUS-FNAC gives a valuable contribution in the diagnoses of all kind of pancreatic masses. Using 22G procore and ROSE method we obtained good samples and observed a good correlation between the cytological and histological diagnoses. The positivity of DPC4 indicates a better prognosis in pancreatic carcinoma.

PS-02-013

Intraocular lymphomas. Clinical and cytological perspective

C. Fuster Anglada^*, V. Llorenç, M. Solé, A. Serrano, A. Adán, I. Aldecoa

^*Hospital Clínic de Barcelona, Anatomic Pathology, Spain

Background & Objective: Describe the characteristics of intraocular lymphomas (IOL) and analyze the most efficient techniques for evaluation.

Method: Retrospective descriptive study of patients with IOL seen at our institution between 1994-2017. The morphological criteria and the role of immunohistochemistry (IHC) and flow cytometry (FC) were analyzed.

Results: Twenty-five samples from 21 patients were analyzed; 18 cytologies (15 vitreous samples, two aqueous humor and a subretinal aspirate), and seven biopsies (three conjunctiva, one iris, two retina and an enucleation). Eleven patients were diagnosed with primary vitreo-retinal lymphoma (PVRL, 52%), four primary uveal lymphoma (PUL, 19%) and six secondary intraocular lymphoma (SIOL, 28%); 90% of the PVRL and 83% of the SIOL were diffuse large B-cell lymphomas, whereas PUL were extra-nodal marginal lymphomas. A primary T lymphoma and a secondary NK were diagnosed. All the cytological samples but two were diagnostic. The most relevant cytological criteria was cell size; most of the cases had medium and large cells. In more than half of the cases nuclear irregularity and pleomorphism were observed. The finding of lymphoglandular bodies, mitosis and necrosis was infrequent. In 16 of 18 cytological samples IHC was performed and confirmed the diagnosis in 14. FC supported the diagnosis in 6 of 9 cases. All biopsies were consistent with lymphoma diagnosis.

Conclusion: PVRL and SIOL are mostly large B-cell lymphomas. The most efficient technique for diagnosis is cytology combined with immunohistochemistry. Biopsy should be restricted to accessible locations or cases with negative cytology.

PS-02-014

Diagnostic accuracy of endoscopic ultrasound-guided sampling techniques of pancreatic lesions in surgically confirmed cases

I. A. Park^*, J. Koh, H. W. Baek, K. B. Lee, B. Shim

^*Seoul National University Hospital, Dept. of Pathology, Republic of Korea

Background & Objective: Endoscopic ultrasound–guided fine needle aspiration cytology and biopsy (EUS-FNAC & EUS-biopsy) are currently the most commonly used sampling techniques of pancreas. This study was aimed to evaluate the diagnostic value of EUS guided sampling techniques in surgically confirmed cases.

Method: A retrospective medical record review of 58 cases of pancreatic lesions with concurrent initial diagnosis by EUS-FNAC & EUS-biopsy and subsequent histologic confirmation by surgical resection between January, 2010 and December, 2013 in Seoul National University Hospital, was done. The diagnoses were compared for statistical analysis for diagnostic accuracy of each procedure. Cases with different diagnosis were considered discordant, and slides were reviewed for analysis.

Results: Compared with final histologic diagnoses of surgically resected specimen, the diagnostic accuracy of EUS-FNAC and EUS-biopsy was 84.5% and 82.8%; sensitivity of EUS-FNAC and EUS-biopsy was 86.3% and 81.5%; specificity of EUS-FNAC and EUS-biopsy was 71.4% and 100%. Combining two techniques diagnostic accuracy progressed to a higher rate to each procedure (91.4% vs. 84.5% and 82.8%, respectively). But the sensitivity and specificity did not show any differences between combination and each procedures. The most common cause of inconsistent diagnosis in EUS-guided sampling techniques is 'insufficient for diagnosis'. The cause of discordance was sampling errors, misinterpretation of suboptimal specimens and misinterpretation of reactive atypia to malignancy.

Conclusion: EUS-FNAC and EUS-biopsy have a comparable diagnostic accuracy, but the combination of these procedures goes favorably.

PS-02-015

The Papanicolau Society of Cytopathology (PSP) pancreato-biliary cytology (pbc) nomenclature: early experience in our centre with endoscopic ultrasound-guided fine-needle aspiration biopsy (eus-fna)

M. Giner Pichel^*, I. Ramos-Oliver, L. Silva, A. Aula, S. Ubalde, J. Roman, J. Temprana-Salvador, M. Alberola, F. García-Fouz, M. Abu-Suboh, C. Dinarès, S. Ramon y Cajal, C. Iglesias

^*Hospital Vall d´Hebron, Anatomía patológica, Barcelona, Spain

Background & Objective: The PSP developed guidelines for pancreatobiliary cytology including indications and techniques for EUS-FNA, terminology and nomenclature of pancreatobiliary disease, ancillary testing and post-biopsy treatment and management. The proposed terminology scheme recommends six categories: Nondiagnostic(I), Negative(II), Atypical(III), Neoplastic (Benign: IVa; Other: IVb), Suspicious (V) and Positive(VI).

Method: Pancreatic EUS-FNA performed in 2016 in our institution (81 cases) were revised and reclassified according to the proposed categories. When necessary, radiology of the lesions and the biochemical tests performed were also considered.

Results: There were no changes in the diagnosis in the cases originally considered as “Negative” (14 cases), “Atypical” (5 cases) or “Suspicious” (5 cases). Two of the 3 cases originally “Negative” were reclassified as “Nondiagnostic”. Of the 13 cases previously diagnosed as “cyst”, 4 were changed to “Nondiagnostic(I)” due to a discordant radiology; 7 to “Negative” category, 1 to “Neoplastic: benign (IVa)” (serous cystadenoma) and 1 to “Neoplastic: other (IVb)” (mucinous cyst). Of the 41 originally “positive” EUS-FNA cases, 3 have been reclassified as a “Neoplastic: other” and corresponding to pancreatic non-high-grade neuroendocrine tumours. The remaining 38 ”Positive” cases included 36 adenocarcinomas, 1 lymphoma and 1 metastasis.

Conclusion: Cystic lesions suffered the greatest changes in reclassification due to additional radiological/biochemical information, which increased the diagnostic accuracy and avoided false negatives in potentially malignant lesions. The “Neoplastic: other” category allowed better discrimination in potentially less aggressive neoplasms, specially in neuroendocrine lesions. Moreover, the new terminology is more objective and understandable and promotes adequate patient treatment.

PS-02-016

Diagnosis of soft tissue lesions: role of fine-needle aspiration cytology

C. Díaz Del Arco^*, I. Ruiz Adelantado, L. Ortega Medina, I. Subhi-Issa Ahmad, M. J. Fernández Aceñero

^*Hospital Clínico San Carlos, Surgical Pathology, Madrid, Spain

Background & Objective: Fine-needle aspiration cytology (FNAC) is a cost-effective, safe and easy-to-perform technique. However, the role of FNAC in soft tissue lesions (STL) is controversial. Our aim is to assess the diagnostic performance of FNAC in soft tissue lesions.

Method: Retrospective study of all FNAC of STL diagnosed in our institution between 2000-2016 (n=234). Clinicopathological data was collected and cytological results were divided into groups and correlated with histological diagnoses.

Results: Most patient were male (53.4%) and patient age ranged between 15 and 94 years (mean: 61.29). Most lesions were located in the head and neck region. 22.6% of cytologies were non-diagnostic and most lesions were diagnosed by FNAC as carcinomas (33.3%), benign STL (17.9%) or inflammatory lesions (17.9%). Malignant STL comprised only 3.4% of all cases. Biopsy was performed in 36.1% of cases. Non-diagnostic cytologies were mainly inflammatory lesions, and carcinomas were histologically detected in 33.3% of inflammatory FNACs. General and specific concordances were 65.9% and 47.1%. Diagnostic sensitivity, specificity, negative and positive predictive values were 71.4%, 100%, 85.7% and 93.8%, respectively.

Conclusion: FNAC of STL is a valuable tool for diagnosing epithelial cysts, carcinomas, lymphomas and benign STL. However, inflammatory smears can be associated with false-negative cases and in some cases a biopsy is required in order to obtain enough material for immunohistochemical (IHC) study. The availability of a multidisciplinary team, clinical and imaging features, ROSE and IHC and molecular techniques is required for improving the role of FNAC of STL.

PS-02-017

The clinical performance of the ultrasound-guided thyroid fine-needle aspiration cytology and molecular testing at a tertiary care hospital

H. Seneldir^*, G. Kir, N. Ozbay, R. B. Girgin, F. Ozen, G. Bas, O. Alimoglu

^*Goztepe Education and Research, Istanbul, Turkey

Background & Objective: This study aimed to establish a profile of the ultrasound-guided thyroid fine-needle aspiration (FNA) cytology and molecular testing examined at the pathology department of the Goztepe Education and Research Hospital of Turkey.

Method: We reviewed 123 cases diagnosed as atypical by FNA cytology on the basis of the Bethesda system who had undergone molecular testing at this institute between January 2016 to March 2018. FNA samples were tested for BRAF, NRAS, and KRAS point mutations by real-time polymerase chain reaction (RT-PCR). The mutational status was correlated with cytology.

Results: All DNAs from 123 FNA samples could be analysed and point mutations were detected in 49 samples (40%). In 57 AUS/FLUS nodules, 13 samples (23%) had point mutations including BRAF (n=4), KRAS (n=6), NRAS (n=6) and BRAF-KRAS (n=3). In 29 nodules diagnosed as follicular neoplasm or suspicious for a follicular neoplasm, 10 samples (34%) had point mutations including BRAF (n=1), KRAS (n=5), and NRAS (n=4). In 13 nodules diagnosed as suspicious for malignancy, 10 samples (77%) had point mutations including BRAF (n=9), KRAS (n=2), NRAS (n=1) and BRAF-KRAS (n=2). In 24 nodules diagnosed as malignancy, 16 samples (66%) had point mutations including BRAF (n=13), KRAS (n=4), NRAS (n=0) and BRAF-KRAS (n=1).

Conclusion: Molecular analysis of FNA samples might be useful for the diagnosis of indeterminate thyroid nodules. This approach might be expected to reduce repeated FNA, needle biopsy, or diagnostic surgery for indeterminate thyroid nodules. Molecular tests may help clinicians to drive patient care and the surgical decision.

PS-02-018

HPV negative cervical adenocarcinoma – rare case of gastric type diagnosed by cytology

S. Stemberger-Papic^*, D. Vrdoljak-Mozetic, D. Versa Ostojic, M. Dinter, R. Rubesa-Mihaljevic, S. Eminovic

^*Clinical Hospital Centre Rijeka, Dep. of Clinical Cytology, Croatia

Background & Objective: To present a case of a patient with gastric type cervical adenocarcinoma, describe the clinical course, diagnostic pathway and the key role of cytology in the diagnostic procedure.

Method: A 56-year-old asymptomatic woman attended the gynaecological clinic for a routine examination. The screening Pap smear was taken and the result was atypical glandular cells possibly of endocervical origin.

Results: The Pap smear revealed sheets and strips with cell crowding and pseudostratification, nuclear enlargement, anisonucleosis, mild chromatin irregularity and prominent nucleoli. The abnormal Pap smear was the first sign of a disease and further diagnostic procedures was suggested. The colposcopy finding was negative (TZ3), the high-risk HPV (Hybrid Capture 2) was negative and the immuno-testing p16/Ki-67 (CINtec Plus) double stain was negative. After two repeated abnormal Pap-smears (AGC), fractionated curretage was performed. The histopathological diagnosis was negative. A follow up Pap smear finding was adenocarcinoma in situ with suspicious microinvasion. Abnormal glandular cells showed simillar features as in the initial Pap smear, but more prominent. Some cell group showed feathering and rosette-like arrangement. Three years after the first abnormal Pap smear conisation was performed and the histopathological diagnosis was mucinous endocervical adenocarcinoma of gastric type. The margins were positive and definitive radical operation was performed.

Conclusion: The finding of AGC in Pap smears demands further procedure and should be taken very seriously. We have to be aware of the fact that a small percentage of cervical cancers could be negative in the initial cloposcopy/histology workup, negative for HR HPV as well as p16/Ki-67 immuno-testing.

PS-02-019

Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) cytology of mesenquimal tumours of the gastrointestinal tract: a 10-year retrospective study of 66 cases

M. Martino^*, M. Revuelta, A. Estebanez

^*HUM Valdecilla, Pathology, Santander, Spain

Background & Objective: Mesenquimal tumours of the gastrointestinal (MTGI) tract due to the deep location are difficult to diagnose by conventional surgery biopsy techniques. EUS-guided FNA has been increasingly used for the preoperative diagnosis of MTGT tract. In reviewing our experience, in this study, our aim is to determinate the accuracy of EUS-guided FNA for the diagnosis of MTGI tract.

Method: Over a 10-year period, a computerized search of the cytopathology laboratory information system was performed and all cases of EUS-guided FNA in which a clinical diagnosis of MTGI tract was suggestive were identified. All correlating surgical pathology report diagnosis were obtained and retrospectively reviewed

Results: A total of 66 patients were clinically diagnosed as MTGI tract, 26 males, 40 females with a mean age of 65 (range 22 to 84 years). The tumour sized from 0,8 to 10 cm (mean: 4,3 cm). 44 cases had a gastric, 15 oesophagic, 4 duodenal, 2 oesophago-gastric and 1 rectal location. There was cell block (BC) in 71,2 % of the cases. 50% of the cases were hipocellular (36% CB), 34,2% gastrointestinal stromal tumours (GIST) (92%CB) and 15,8% (75% CB) leiomyomas. Immunohistochemistry (IHC) stains were performed (C-KIT, actin, CD34, DOG1 and ki67). Follow-up histology diagnoses were found in 35 (53%): 15 EUS-FNA GIST (all of them histologically confirmed), 8 EUS-FNA leiomyomas (7 confirmed) and 12 EUS-FNA hipocellular (8 GIST, 2 leiomyomas and 2 schwannomas).

Conclusion: EUS guided FNA along with CB and IHC stains are an accurate method of establishing a preoperative pathologic diagnosis of MTGI tract.

PS-02-020

Diagnostic performance of fine needle aspiration for thyroid nodular pathology. Analysis of 921 cases

S. Marcos González^*, R. Sánchez Pacheco, I. Hernández Alconchel, J. García Reyero, P. Lastra García-Barón, A. Fernández Flórez, R. Ugalde Herrá, R. Mazorra Horts, P. Bueno Ortíz, M. Martino González, M. A. Revuelta Montoya, J. Martín López, M. L. Cagigal Cobo

^*Hospital Universitario Marques de Valdecilla, Santander, Spain

Background & Objective: Ultrasound-Guided Fine Needle Aspiration (UG-FNA) for thyroid, has been shown to be sensitive and specific to establish a diagnosis. 921 cases of UG-FNA are presented in order to assess the efficacy and know the performance of this procedure in our hospital.

Method: A descriptive, retrospective, study was carried out, analyzing the thyroid FNA from 2011 to the present year, with a total of 921 cases, reclassifying the cytological diagnoses according to The 2017 Bethesda System for Reporting Thyroid Cytopathology, correlating with clinical data and histological diagnoses in cases with surgical procedure.

Results: In our serie, 921 patients are classified into: Bethesda I: 50.4% (n=464), II: 37.6% (n=346), III: 2.5% (n=23), IV: 5% (n=47), V: 2.3% (n=21) and VI: 2.2% (n=20). The correlation of these results with the surgical sample are: Within Bethesda III, 21.7% malignant histology, 43.5% benign histology and 34.8% without surgical procedure. In Bethesda IV, 19.1% malignant histology, 42.6% benign histology and 38.3% without surgical procedure. Bethesda V, 90.5% malignant histology, with 9.5% without surgical procedure, and Bethesda VI: 75% malignant histology with 25% without surgical specimens.

Conclusion: The sensitivity of UG-FNA for the diagnosis of malignancy is high. There is a good correlation (in categories III and IV) of the risk of malignancy with respect to the 2017 Bethesda System for Reporting Thyroid Cytopathology. This work has led to a prospective work to improve the high percentage of unsatisfactory samples, in collaboration with the radiology department.

PS-02-021

Fine-needle aspiration cytology of the thyroid. A 10-year retrospective study of 3,531 samples from a single institution. Bethesda System and cytology-histology correlation

M. Martino^*, C. Azpiazu, S. Montes, I. Lastra

^*HUM Valdecilla, Pathology, Santander, Spain

Background & Objective: Fine-needle aspiration (FNA) cytology of thyroid nodules is a common practice. Bethesda system for reporting thyroid cytology (BSRTC) is intended to standardize terminology and offers specific cytology categories to facilitate more useful reporting and increased knowledge of the inherit risk of malignancy. This study was conducted to investigate the impact of using BSRTC diagnostic criteria on FNA diagnosis.

Method: All thyroid FNA cases were identified in a retrospective review between January 2008 and December 2017. BSRTC were used: non-diagnostic (BS1), benign (BS2), atypical/follicular lesion of undetermined significance (BS3), follicular neoplasm (BS4), suspicious for malignancy (BS5) and malignancy (BS6). Correlating surgical pathology report diagnosis of BS3, BS4 and BS5-6 were retrospectively reviewed.

Results: 3531 cases of FNA thyroid cytology were diagnosed, 2976 (84%) females and 555 (16%) males, with a mean age of 52 (range 12 to 91 years). There were 1858 (53%) BS1, 1078 (30,5%) BS2, 160 (4,5%) BS3, 279 (8%) BS4 and 156 (4%) BS5 y BS6. There were 431 histological follow ups: 121 (75,6 %) in BS3 with a malignant diagnosis (MD) in 28 (23%), 173 (62%) in BS4 with MD in 21 (12%) and 137 (87%) in BS5 and BS6 with a MD in 83%.

Conclusion: The risk of malignancy in BS3 is 5-15%, in BS 4 15-30% and in BS 5-6 60-99%. Our data reveal a higher percent of MD in BS3 and a slight lower percentage of MD in BS4. BS1 is 53% and liquid base cytology should be implemented to try to reduce it.

PS-02-022

Is the concurrent use of p16 and Ki-67 biomarkers an effective diagnostic tool for low grade squamous intraepithelial lesion of the cervix?

A. Stanek-Widera^*, M. Biskup-Fruzynska, B. Nikiel, D. Lange

^*Institute of Oncology, Tumour Pathology, Gliwice, Poland

Background & Objective: The implementation of CINtec PLUS, an immunocytochemical (ICC) assay which features dual staining of p16 and Ki-67, allows the identification of squamous intraepithelial lesions of neoplastic character. The aim of the study was to examine scanned slides of cervical smears stained first by routine (Papanicolaou) method and then in CINtec PLUS, compare the diagnoses and correlate them with histopathological results.

Method: The slides of 176 cases of archival routinely stained cervical smears: 88 LSIL, 58 ASC-US, 10 ASC-H, 10 HSIL and 10 cancers were scanned and destained. After restaining in CINtec Plus, the slides were scanned again, and the digital images were compared, allowing analysis of the very same cells.

Results: In 69% of LSIL, one to several dozens of ICC(+) cells were found, a few positive cells were spotted in only 27% of the ASC-US group, and 80% of ASC-H smears showed positive cells. In 100% of smears harbouring HSIL and cancer there were numerous p16/Ki67(+) cells. The observation period was 3 to 5 years. In one case of ASC-H further histopathological evaluation revealed cancer. In all cytological HSIL and cancer cases there was histopathological confirmation of at least high-grade dysplasia. Repeated Pap test and colposcopy in patients with LSIL and ASC-US showed low grade squamous intraepithelial lesions only in two cases.

Conclusion: Destaining of the routinely processed cytological smears and restaining with CINtec PLUS allows more accurate cytological diagnosis and classification of the smears to a category of high grade squamous intraepithelial lesions.

Sunday, 9 September 2018, 09:30 - 10:30, Exhibition Hall I/II

PS-03 | Endocrine Pathology

PS-03-001

Histological scores for diagnosis of adrenocortical carcinomas – are they enough?

R. Almeida^*, R. Caetano Oliveira, J. Carvalho, P. Teixeira, C. Moreno, E. Tavares Silva, A. Figueiredo, M. J. Martins

^*CHUC, Pathology, Coimbra, Portugal

Background & Objective: Adrenocortical carcinomas (AAC) diagnosis is a challenge for pathologists, especially in borderline cases. In the last years some scores have been proposed for the evaluation of AAC; Weiss modified system (WMS) is the most commonly used.

Method: Retrospective evaluation of the ACC (2004-2016): 16 patients, median age of 50.5±10.16years (11F:5M). AAC had a median of 9.35±6.66cm (5.5-28) and 213±765,58g (34-2600). ACC was an incidental finding in 62.5% of patients; hormone production present in 31.3%. Ancillary evaluation: P53, Ki67 and Gordon&Sweet. Application of WMS, Reticulin algorithm (RA) and Helsinki score (HS).

Results: After a median follow-up of 31±48.72 months the overall survival (OS) was of 56.3% and 45% at 3 and 5-years. Disease-free survival (DFS) of 13.5±43.02months: five patients with local recurrence and seven with metastasis. Three lesions were benign with WMS, two with RA and three with HS criteria. Histologic characteristics: 62.5% had vascular invasion, 81.3% had necrosis and 50% had capsular invasion. Majority were staged as T2 (68.8%), and in this subgroup, size>10cm was associated with poorer OS (p=0.036). Ki67 had a median of 9.6±11.76% (2-43.70). Gordon&Sweet showed diffuse loss in fourteen cases and focal in two. P53 had abnormal staining in nine. Higher staging was predictor of poorer OS (p=0.011), as well as more than 5mitosis/50HPF (p=0.012). No factors were identified of better DFS.

Conclusion: Histological scores are precious auxiliaries in the ACC diagnosis, but can miss some borderline cases. The conjugation of size and weight can be helpful in some situations. Staging and mitotic index are powerful predictors of OS.

PS-03-002

Ribonuclease T2 (RNASET2) expression in the spectrum of neuroendocrine neoplasms of the lung. Relationships with hypoxia-related mechanisms and microvascular patterns

R. Maragliano^*, D. Scaldaferri, L. Monti, E. Sorrenti, M. Gariboldi, R. Taramelli, F. Sessa, F. Acquati, S. La Rosa, S. Uccella

^*Unit of Pathology, University of Insubria, Varese, Italy

Background & Objective: RNASET2 exerts several different activities in neoplastic cells since the early steps of tumour development such as growth suppression and antiangiogenic activity. No data on its expression in neuroendocrine neoplasms of the lung (Lu-NENs) are available. We investigated RNASET2 expression in well-differentiated (WD) and poorly differentiated (PD) Lu-NENs. In addition, we explored possible relationships between RNASET2 expression and a series of immunohistochemical markers related to hypoxic stress, apoptosis, proliferation and angiogenesis.

Method: Twenty-nine surgically resected Lu-NENs diagnosed between 2007 and 2016 were analyzed and compared to normal lung tissues from six lobectomies. Immunohistochemical stains for RNASET2, HIF-1 alpha, CAIX, M30, synaptophysin, chromogranin A, CD31 and CD34 were evaluated. RNASET2 expression was also measured with quantitative RT Real Time PCR. HIF-1 alpha expression in transfected cells was evaluated 48h after transfection by western blot analysis.

Results: Our results showed a significantly higher expression of RNASET2, HIF-1 alpha, and CAIX in PD Lu-NENs, associated with a higher proliferation and apoptotic rates, as well as a lower microvessel density (MVD) compared to WD Lu-NENs. In vitro, we demonstrated an overexpression of RNASET2 consequent to the activation of HIF-1 alpha.

Conclusion: We suggest that in PD Lu-NENs, RNASET2 expression may be induced by HIF-1 alpha. In this aggressive group of cancers, RNASET2 fails to exert the growth-inhibiting effects described in other types of neoplasms. However, it may contribute to the typical phenotypic alterations seen in poorly differentiated Lu-NENs, such as low MVD, high apoptotic rate and extensive necrosis.

PS-03-003

IgG4-related hypophysitis: report of two cases and revision of the literature

C. Amaglio^*, J. P. Brouland, E. Bianconi, M. L. Tanda, D. Locatelli, F. Sessa, S. La Rosa, S. Uccella

^*Unit of Pathology, Dept. of, Medicine and Surgery, University of Insubria, Varese, Italy

Background & Objective: IgG-4 related disease (IgG4-RD) encompasses different disorders, sharing biochemical and morphological features. Elevated IgG4 serum levels may be elevated. The pituitary gland is a rare target site and IgG4-related hypophysitis (IgG4-RH) is not yet well characterized among primary hypophysitis. Here we present two cases of IgG4-RH and review the literature, to discuss the histopathological criteria for the diagnosis.

Method: Case 1: a male patient aged 66 presented with hyperprolactinemia and hypogonadism. MRI showed a sellar/extrasellar mass. A non-functioning (NF) pituitary neuroendocrine tumour (Pit-NET) was hypothesized and the patient underwent trans-sphenoidal surgery (TSS). Case 2: a female patient aged 22 presented with headache and galactorrhea. MRI showed an intrasellar mass, suggesting a Pit-NET. From PubMed data base (https://www.ncbi.nlm.nih.gov/pubmed), we selected all case reports of IgG4-RH, using the key words hypophysitis [AND] IgG4. Clinico-pathological features were recorded and compared with those of our cases.

Results: In both cases, pituitary tissue with an abundant lymphoplasmacytic infiltrate, storiform fibrosis and high numbers of IgG4 plasma cells per HPF were observed and IgG4-RH was diagnosed. We retrieved 17 histopathologically documented cases of IgG4-RH from previous literature. Our overall review highlighted that specific criteria for IgG4-RH are missing, despite the differential diagnosis of this condition from other primary or secondary hypophysitis is therapeutically crucial.

Conclusion: IgG4-RH is a rare condition, which benefits from corticosteroidal therapy and should be differentiated from other conditions affecting the pituitary gland. Our results suggest that diagnostic criteria for IgG4-RH should be better defined and may be different from those applied for IgG4-RD in other organs.

PS-03-004

Primary pigmented nodular adrenocortical disease - the role of the pathologist in the diagnosis of hereditary syndromes

C. Pedrosa da Costa^*, C. Costa, D. Melo, E. Rios

^*Centro Hospitalar de São João, Surgical Pathology, Porto, Portugal

Background & Objective: Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of ACTH-independent Cushing’s syndrome, which can be either isolated or associated with Carney Complex (CC). The latter is a rare familiar syndrome, usually caused by a germline mutation in the PRKAR1A gene. Herein we report a case of CC diagnosed after histological evidence of micronodular adrenal hyperplasia (MiAH).

Method: A 17-year-old girl was referred to our hospital due to obesity and Cushingoid appearance. She had a family history of sudden death (father). Endocrinological workup confirmed the diagnosis of ACTH-independent Cushing’s syndrome. MRI disclosed normal adrenal morphology. Scintigraphy displayed focal left adrenal hyperfixation, being consistent with a functional adenoma. Left adrenalectomy (12g) was performed.

Results: Grossly multiple brown nodules (largest dimension <5mm) were seen throughout the cortex and, occasionally, in the periadrenal tissue. Histologically, the nodules were composed of lipofuscin-containing cells. The diagnosis of MiAH, most probably corresponding to a PPNAD, was made. Molecular study revealed a heterozygous inactivating germline mutation of PRKAR1A, supporting the diagnosis of CC. Follow-up disclosed no other features of CC.

Conclusion: CC is a rare familiar syndrome with an autosomal dominant inheritance characterized, among others, by endocrine hyperactivity, which presents more often with Cushing’s syndrome caused by PPNAD. Diagnosis of this rare condition can be challenging as imaging may not always identify the bilateral micronodular changes, which require a definite pathological diagnosis. This case represents an extremely unusual hereditary syndrome and highlights the importance of observation and documentation by pathologists.

PS-03-005

PDCD1 (PD-1) promoter methylation as a new prognostic marker in localised (stage I-II) Merkel cell carcinoma

F. Ambrosi^*, L. Morandi, F. Maletta, C. Ricci, D. Gibertoni, A. Righi, M. G. Papotti, M. P. Foschini, S. Asioli

^*Dept. of Pathology, University of Bologna, Italy

Background & Objective: Merkel cell carcinoma (MCC) is an aggressive neoplasm, whose prognostic criteria are a matter of dispute, specifically for localized (stage I-II) tumours. Programmed death-1 (PD-1) proved to be a key player of the tumour microenvironment, with agents blocking the PD-1/PD-L1 axis showing efficacy in these patients. DNA promoter methylation of programmed cell death 1 (PDCD1, PD-1) was evaluated as a prognostic biomarker in MCC.

Method: We collected clinical, pathological and follow-up data of 62 Merkel cell carcinomas of the skin. PDCD1 methylation (mPDCD1) was retrospectively assessed by bisulfite-Sequencing. Prognostic parameters were evaluated with Kaplan-Meier failure estimates, log-rank tests and Cox proportional hazards regression.

Results: There were 36 (58.1%) men and 26 (41.9%) women, aged from 60 to 95 years (74.6±10.7). Stages I and II were prevalent (56.5%), with only 6.4% patients in stage IV. High level of mPDCD1 was found in 37.1% of patients, unrelated to stage (χ2 = 0.290, p=0.590). High mPDCD1 was associated with a significantly shorter overall survival in stage I and II (HR=3.05, p=0.021), even adjusting for age and tumour size (HR=3.29, p=0.017). In the overall cohort, older age (HR=2.15, p=0.041) and tumour size >2cm (HR=2.12, p=0.040) were the only parameters associated to a shorter overall survival.

Conclusion: Our data support the role of the PD-1/PD-L1 interaction in creating a local tumour-specific immune response, representing a favorable prognostic factor in localized Merkel cell carcinomas and providing a rationale to improve investigation of PD-1/PD-L1 axis, as currently studied in melanoma and head and neck squamous cell carcinomas.

PS-03-007

Clinico-pathological features of adrenal tumours in young adults, a retrospective study

I. Dumitru^*, C. Ajzenberg-Gauthieh, L. Salomon, M. Nourieh

^*Emergency University Hospital, Pathology, Bucharest, Romania

Background & Objective: Adrenal tumours are rare in patients aged below 40 years. The aim of this study is to describe the clinico-pathological features of adrenal tumours in young adults.

Method: We retrospectively analyzed clinical and pathological data of 296 adrenal tumours treated at our institution from January 2000 to December 2017. Score of Weiss, PASS and Biceglia were established.

Results: 49 out of 296 patients (were under 40 years old (range age, 18 to 39.9 years). 12 patients were male (24%), and 37 were female (76%). Most tumours were pheochromocytomas (n=20) followed by adrenal cortical adenomas (n=13). Adrenocortical carcinoma was less presented (n=2). One composite pheochromocytoma was observed in patient with neurofibromatosis type 1. Three patients had bilateral pheochromocytomas; two of them had a Multiple Endocrine Neoplasia Type 2B. One patient had metastatic pheochromocytoma and succinate dehydrogenase subunit B mutation. The highest PASS and Weiss scores were respectively 14 and 3 (mean of 3 median of 2).

Conclusion: Adrenal tumours in young adults represent in our study 18 % of all adrenal neoplasms. They are most frequent in women. Pheochromocytomas are the most frequent tumour observed in our series and tend to have a low PASS score. Some cases are observed in familial syndromes. Adrenocortical carcinoma is uncommon in young adults and represents less than 4% of cases.

PS-03-008

Ultrastructure cell-cell interconnections in neuroendocrine neoplasms of the pancreas

E. Gordienko^*, O. Paklina, I. Chekmareva, A. Kaldarov

^*Botkin Hospital, Pathology, Moscow, Russia

Background & Objective: Potential role for desmosomes and gap junctions in cancer progression has been suggested based on a variety of experimental clues. Difference in cell-cell interconnections between benign insulinomas and more aggressive nonfunctioning (NF) neuroendocrine tumours of the pancreas is generating scientific interest

Method: The material from 18 patients with insulinomas and 15 NF neuroendocrine tumours was investigated using electron microscopy

Results: Insulinoma cells were connected to each other and held together by desmosomes, providing a very tight connection. Desmosomal complexes were characterized by increased osmiophilia and increased length. The presence of a large number of mature desmosomes between tumour cells in insulinomas explains their strong adhesion. A significant number of gap junctions were determined in insulinoma. In NF tumours was dominated by simple contacts. Plasmolemma of the contacting cells are clearly visualized. Desmosomes were rare, were poorly developed. Gap junctions were isolated. Ruptures of intercellular contacts with the formation of cytoplasmic bridges led to the formation of syncytia-like structures in both insulinomas and NF tumours. In insulinoma near the rupture of membranes was determined by strong intercellular connections such as desmosomes. In the NF tumours did not note the "consolidation" of the rupture site. Predominance of weak simple contacts, reduction of desmosomes in NF can contribute to easier separation of individual tumour cells and formation of metastases

Conclusion: The acquisition of an invasive phenotype and further the ability to metastases NF tumours of the pancreas in comparison with the insulinoma was confirmed at the ultrastructural level, the peculiarity of intercellular interactions

PS-03-009

Pathological evaluation of prognostic parameters in tall cell thyroid carcinoma: a study

C. Brunelli^*, T. Musarra, C. De Marco, P. Straccia, M. Martini, E. D. Rossi, G. Petrone, G. Fadda

^*Fondazione A. Gemelli, Surgical Pathology, Roma, Italy

Background & Objective: Tall cell variant (TCV) of papillary thyroid cancer (PTC) represents an aggressive variant of PTC and should be reported when 10% is present in an otherwise usual PTC. Aim of this study is to evaluate the correlation between different rates of TCV with the most important histological prognostic parameters to stratify patients for a correct management.

Method: We analysed 96 patients with a TCV pattern of PTC and on those were evaluated the rate of the TCV variants 0-20% (group 1), 21-49%(group 2), 50% or higher (group 3). The three groups were matched with the following prognostic parameters: multifocality, invasion of thyroid capsule, peritumour vessels invasion and cervical nodal metastases (subdivided into micro- and macrometastases).

Results: Out of 96 cases 41 were in group 1, 38 in group 2 and 17 in group 3. Regarding the group 1 21 cases were multifocal, 22 infiltrate the thyroid capsule, 21 showed vessels invasion, 22 had nodal metastases (17 of them resulting macrometastases). In group 2 20 were multifocal, 21 showed capsule and 5 vascular invasion, 27 presented nodal metastases (20 macrometastases). In group 3 10 were multifocal, 15 showed capsule infiltration and 3 vascular invasion, 15 presented nodal metastases (13 macrometastases)

Conclusion: Although the series is still limited the statistical analysis shows significant correlation between groups 1 and 3 for capsular invasion (p = 0.0163), for vascular invasion (p = 0.0216) and nodal metastases (0.0163) and a correlation between groups 2 and 3 for capsular invasion (p =0.0299) confirming the aggressiveness of TCV in PTC.

PS-03-010

DICER1 alterations are more frequent in oncocytic, follicular and rare aggressive variants than in classical papillary thyroid carcinoma

S. Canberk^*, L. Pereira, R. Batista, P. Soares, V. Máximo, M. Sobrinho Simões

^*IPATIMUP/ i3S, Cancer Signaling & Metabolism, Porto, Portugal

Background & Objective: Dysregulation of DICER1 has been described in different human tumours. Due to insufficient data indicating the risk of thyroid cancer in the presence of germline and somatic mutations of DICER 1, we analyzed the presence of DICER 1 alterations in Papillary Thyroid Carcinoma (PTC) cases obtained from The Cancer Genome Atlas Research Network.

Method: Histomorphology characteristics of 501 PTC cases from TCGA were re-evaluated. Genetic information concerning DICER 1 status was extracted from TCGA. DICER1 germline alterations with allelic frequency lower than 0.02 (n=14) were selected for analysis; as well as cases presenting DICER 1 somatic mutations (n=3). Clinical information -when available- was added.

Results: The 14 cases with DICER 1 germline alterations in less than 0.02% were diagnosed as oncocytic variant (n=7), follicular variant (n=4), classical PTC (n=2) and one columnar-cell variant. Somatic DICER1 mutations were detected in 3 PTC cases; oncocytic variant (n=2) and one follicular variant. In total 9 cases of the oncocytic variant PTC and 5 cases of follicular variant of PTC out of 17 cases presented DICER1 mutations. The percentage of DICER 1 mutation is higher in oncocytic variant of PTC (9/156) as well as in follicular variant (5/131), and in rare aggressive variants (1/24) than in classic PTC (2/164).

Conclusion: DICER1 alterations were encountered more frequently in oncocytic, follicular and rare aggressive variants of PTC than in classic PTC using the TCGA data. The association of DICER 1 with the aforementioned variants may open an avenue for research and will be explored in our laboratory.

PS-03-011

Impact of thiadiazines and lipoic acid on protection of pancreatic islets, liver and kidney in diabetic rats

G. Irina^*, E. Victor, D. Irina, B. Tatyana, S. Larisa

^*Ural Federal University, Chemical Engineering Institute, Yekaterinburg, Russia

Background & Objective: Treatment of diabetes mellitus (DM) requires antidiabetic drugs with multiple impacts. Previously, we have identified synthetic 1,3,4-thiadiazine derivatives, L-17 and L-14, which combine antioxidant and antiglycative properties. The aim of the work is to reveal whether L-17 and L-14 can contribute to the pancreatic islet, liver and kidney protection in diabetic rats when compared with a natural antioxidant lipoic acid (LA).

Method: Forty male Wistar rats weighing 220-250 g were used in accordance with the ethical principles of the Directive 2010/63/EU. Alloxan was injected intraperitoneally (300 mg / kg) that provides a model type 1 DM. Aqueous solutions of the drugs were administered intramuscularly (40 mg/kg per day, 12 injections for 30 days) to diabetic and healthy rats. Biochemical, morphometric and immunohistochemical investigations were performed.

Results: We revealed an increase in diameter and cell number in the pancreatic islets after LA and L-17 administration to healthy rats. The injections of L-17, L-14 and LA to diabetic rats were accompanied by a decrease in glucose, glycated hemoglobin and creatinine content, but not the aminotransferase activity (AST, ALT). An increase in the number of β-cells occurred only in diabetic rats treated with LA and L-14.

Conclusion: Therefore, L-17, L-14 and LA reduce hyperglycemia and kidney damage marker without ameliorating liver damage markers in diabetic rats. The impact of L-14 on the β-cell survival is comparable to that of the LA and is more pronounced than that of L-17.

PS-03-012

Prevalence and clinicopathological features of papillary thyroid carcinoma – analysis of the cases of a single institute for a period of 20 years

R. Ivanova^*, P. Karanova, R. Kovacheva, A. Shinkov, T. Sechanov, N. Kanev, K. Vidinov

^*Hospital of Endocrinology, Lab. of Clinical Pathology, Sofia, Bulgaria

Background & Objective: Among the many variants of papillary thyroid carcinoma (PTC), papillary microcarcinoma (PMC) is the one with excellent prognosis and increasing incidence worldwide over the last 20 years. The aim of this study was to analyze the prevalence and clinicopathological features of PMC in our institute for a period of 20 years.

Method: A total of 1374 consecutive patients with PTC, including 618 patients with PMC, who received surgical treatment from 1996 to 2015 were included. The prevalence and clinicopathological features of cases with PMC were compared to the cases with other variants of PTC during the individual 5-yrs (1996-2000, 2001-2005, 2006-2010 and 2011-2015) and 10 -yrs (1996-2005 and 2006-2015) study periods.

Results: PMC was the most frequently diagnosed variant of PTC (45%) in our series of PTC, with increasing prevalence by 18% during the second 10-yrs period. PMC was more common in females (89%) than in males (11%, p<0.0001) and 77% of all cases were aged below 55 yrs. The tumour size varied from 0.2 to 1.0 cm, in 43% - up to 0.5 cm. The percentages of histologically diagnosed thyroid capsule invasion, tumour multifocality and lymph node metastasis were low – 2%, 8%, and 11%, respectively. There was relationship between LN metastasis and tumour multifocality (p<0.001), and size (p<0.05).

Conclusion: Our results show that PMC was the most common variant of PTC, also with increasing prevalence for the study period. In small number of patients are present lymph node metastasis and multifocality and their identification preopreratively is essential for the choice of treatment.

PS-03-013

NIFT-P and cytology – can overtreatment of thyroid tumours be reduced?

T. Maia^*, I. Amendoeira

^*Centro Hospitalar Sao Joao, Anatomic Pathology, Porto, Portugal

Background & Objective: The recognition of NIFT-P by WHO Classification of Tumours of Endocrine Organs (4th edition) as a low malignant potential tumour is associated with a significant impact in fine needle aspiration (FNA) cytology interpretation and categorization in Bethesda System for Reporting. Recalculation of the risk of malignancy (ROM) is therefore needed for each Bethesda category.

Method: Between 2006-2016, 11639 thyroid nodules were submitted to FNA in Centro Hospitalar de São João. We reviewed the cytological and histological features of the 345 surgical specimens classified as follicular variant of papillary thyroid carcinoma. The cases were reclassified according to NIFT-P criteria. ROM before and after reclassification were calculated for each Bethesda category.

Results: 109 cases were reclassified as NIFT-P (31.6%). The decrease in ROM before vs after reclassification was statistically significant (p<0.05) in the indeterminate categories: in Bethesda category III (atypia/follicular lesion of undetermined significance) the decrease was 4.9% (17.8%-12.9%); in Bethesda category IV (follicular neoplasm/suspicious for follicular neoplasm) the decrease was 10% (37,5%-27,5%); in Bethesda category V (suspicious for malignancy) the decrease was 13.5% (80.2%-66.7%).

Conclusion: Our results concur with those of other published series: a decrease in ROM was verified mainly in the intermediate categories. Therefore, we suggest that whenever a follicular patterned tumour with papillary-like nuclear features is considered in a FNA specimen, the Bethesda category IV should be used instead of a Bethesda category V, thus leading to lobectomy instead of total thyroidectomy. With this approach patients may be spared from overtreatment.

PS-03-014

EGFR mutation in thyroid carcinomas

S. Erkilic ^*

^*Gaziantep University, Pathology, Turkey

Background & Objective: The majority of thyroid cancers are well differentiated carcinomas. However, some of the well differentiated carcinomas as well as other carcinomas of the thyroid show an aggressive course. There is no specific treatment except RAI. Epidermal growth factor receptor (EGFR) mutations are commonly used for targeted therapy in lung adenocarcinoma There are few data on EGFR mutations in thyroid cancer in the literature. The aim of this study was to investigate the presence of EGFR mutations, especially in aggressive thyroid carcinomas.

Method: In a retrospective study, we studied 118 patients with thyroid carcinoma and followed up between 2002 and 2017. EGFR mutation status in exons 18, 19, 20 and 21 was examined from the paraffin blocks of patients by real-time PCR (Cobas® 4800).

Results: Classic or tall cell variant of papillary thyroid carcinoma was diagnosed in 37 out of 118 patients. These patients had lymph node or distant metastasis or recurrent disease. 8 patients were diagnosed with follicular carcinoma, 5 of them were encapsulated with capsular and vascular invasion and 3 patients were widely invasive. Seventeen patients had poorly differentiated carcinoma and 32 were anaplastic thyroid carcinoma. Twenty-four patients had medullary carcinoma with a lymph node metastasis greater than 1 cm in diameter. EGFR exon 18, 19, 20 and 21 mutations were not observed in any of the 118 cases.

Conclusion: Although there are several immunochemistry studies reporting overexpression of EGFR in thyroid carcinomas, molecular evidence is lacking. Targeted therapies to treat thyroid carcinoma remain an area of research.

PS-03-015

Extra-islet insulin-producing cells in experimental diabetes mellitus and at modulation activity of macrophages

K. Sokolova^*, I. Gette, I. Danilova, M. Abidov

^*Ural Federal University, Dept. of Natural Science, Yekaterinburg, Russia

Background & Objective: Damage and dysfunction of β-cells lead to hyperglycemia. That is why β-cells are the main target of regenerative therapy of diabetes. Insulin-producing cells (IPC), located solitary or in clusters, may occur in acinar part or in ducts of the pancreas. Proposed, that formation of such cells occurs due to the damage of pancreas, mediated by macrophage infiltration of organ. Strategy, aims to proliferation and maturation of these specific β-cells subpopulations, may represent a promising direction in the regulation of hyperglycemia. Objective: to characterize quantity, localization, functional activity of extra-islet IPC in diabetic rats and after modulation macrophage activity.

Method: 20 Wistar rats were divided into 4 groups: 1 – control; 2 and 3 – 30 and 60 days of streptozotocin-induced diabetes correspondingly, 4 – 30 days of diabetes + injection of 3-aminophtalhydrazine derivatives, which modulate macrophage activity and reduce inflammation. Insulin-positive cells were detected by immunohistochemistry.

Results: In 30 days of diabetes number of solitary IPC in acinar part increased more than 3 times with normal functional activity level and decreased in 60 days. Number of IPC in ducts at diabetes almost unchanged. Modulation of macrophages activity promotes increase the number of solitary IPC in acinar and ductal parts and ductal insulin-positive clusters as well; growth of functional activity of extra-islet IPC was detected.

Conclusion: Exposed increase of number and functional activity of endocrine extra-islet cell subpopulations proves heterogeneity and plasticity of pancreatic cells, due to which they can serve as an additional source of β-cells, while macrophage-centered therapy offer promising possibilities at correction of hyperglycemia.

PS-03-017

Modeling effect of heavy metals salts and glucocorticoids on the secretion of parathormone in the experiment

A. Romaniuk^*, N. Hryntsova, O. Timakova, Y. Lyndina, A. Korobchanska, A. Honcharova, V. Sikora

^*Sumy State University, Pathology, Ukraine

Background & Objective: In some regions of Ukraine there is an increase in the accumulation of heavy metals in soil and drinking water. In this work is studied the functional state of the parathyroid gland and adrenal glands of rats under conditions of influence of salts of heavy metals.

Method: The experiment was conducted on 24 rats aged 5-6 months. Animals received drinking water, saturated with a combination of salts of heavy metals: zinc, copper, iron, manganese, lead and chromium. The rats were withdrawn the experiment by decapitation under etheric anesthesia according to ethical norms. The concentration and indexes of cortisol COR (nmol/L) and parathormone PTH (pg/ml) concentration and indices were determined by auto immunohymoluminescence assays in serum.

Results: In experimental animals, the level of COR was <27.6±4.8nmol/L, which is 2.6 times less in the control animals. These data correlate with the optical density indexes, which are inversely proportional to the concentrations of the hormone and are 5.49±0.53, which are 2.0 times higher than in the control animals. The concentration of PTH in control and experimental animals does not reveal significant numerical changes and is <3.0pg/ml. However, the optical density of PTH according to the manufacturer's annotation is directly proportional to the concentration of the serum hormone and is 56.1±1.52, which is 18.3% less than in the control animals.

Conclusion: Heavy metals salts have a negative modeling effect on the level of glucocorticoids, which in turn stimulates dysfunctional disorders from the side of the parathyroid glands in the form of hypofunction.

PS-03-018

Manifestation of the regenerative potential of beta cells of pancreatic islets during modulation of macrophage activity under conditions of experimental diabetes mellitus

K. Sokolova^*, I. Gette, I. Danilova, T. Bulavintseva, M. Abidov

^*Ural Federal University, Dept. of Natural Science, Yekaterinburg, Russia

Background & Objective: Damaged pancreatic tissue possesses the ability to regenerate itself. Modulation of macrophages activity stimulates regeneration of different tissues, which may express in the increase of size, quantity and functional activity of cells and may use to restore the structure and function of pancreatic islets in therapy of diabetes. Objective: to characterize quantity, functional activity and rate of proliferation of β-cells in the islet of Langerhans at macrophage modulation in experimental diabetes type 2 (CD2).

Method: 15 Wistar rats were divided into 3 groups: 1 – intact, 2 – 60 days of CD2 (streptozotocin-nicotinamide model), 3 – after 30 days of CD2 3-aminophtalhydrazine derivatives, which modulate macrophage activity, were injected for 30 days to reduce inflammation. Insulin-positive and Ki-67-positive cells were detected in pancreas tissue by immunohistochemistry, using fluorescent marker. Optical density of insulin in β-cells was measured.

Results: Damage of insulin-producing islet apparatus in experimental CD2 involves decreasing of quantity and functional activity of β-cells and quantity of islets as well; proliferation level of β-cells higher than at intact rats, which have no Ki-67 positive cells at all. At macrophage modulation functional activity of β-cells and quantity of Ki-67-positive cells significantly increases in comparison with CD2 and intact meanings.

Conclusion: Appearance of proliferating islet β-cells at experimental diabetes may be considered as a compensation of reducing their quantity. Sharply increased quantity of proliferating islet β-cells in addition with the growth of their functional activity during macrophages modulation may be used in the treatment of diabetes.

PS-03-019

The oncofoetal protein IMP3 can predict aggressive behaviour and poor clinical outcome in neuroendocrine tumours

L. Gurevich^*, I. Kazantseva, N. Korsakova, M. Byakhova, V. Ashevskaya, I. Voronkova

^*Moscow Regional Clinical Research Institute, Pathology, Russia

Background & Objective: Oncofetal protein IMP3 or insulin like growth factor 2 mRNA binding protein 3 (IGF2BP3) is expressed in tissues in the early stages of embryogenesis. In normal tissues of adult organisms, IMP3 is not detected.

Method: We measured the expression of IMP3 in 55 neuroendocrine tumours (NET) of different localization and malignancy: 27 NET pancreas (25 G1-G2, 2 G3), 8 stomachs (3 G1-G2, 5 G3), 8 intestines (6 G1- G2, 2 G3), 5 Merkel G3 carcinomas, 33 lung tumours (6 typical and atypical carcinoids - TC, ATC, 9 small cell and 3 large-cell NEs). The comparison group consisted of 24 adenocarcinomas (AC) (6 pancreas, 6 stomachs, 3 intestines, 9 lungs) and 7 squamous cell lung cancers (SCLC).

Results: IMP3 expression was observed in the cytoplasm of cells 20/26 (76.9%) of NEC G3 (2/2 pancreas, 4/5 of the stomach, 2/2 of the intestine, 4/5 of Merkel's carcinoma, 12/12 of the lung) and was absent in all 40 highly differentiated NET (34 NET pancreas, stomach and intestine G1-G2 and 6 TC and ATC lungs). In the comparison group, intensive expression of IMP3 was observed in 71.2% (19/24) AC (6/6 pancreas, 5/6 of the stomach, 2/3 of the intestine, 6/9 of the lung) and 85.7% (6/7) of the SCLC. IMP3-negative were more often highly differentiated AC lungs (like lapidary type AC lung).

Conclusion: The expression of IMP3 in neuroendocrine tumours of any site is a marker of an aggressive behavior and poor clinical prognosis that differs little from that of adenocarcinomas.

PS-03-020

Multiple scoring systems in oncocytic adrenocortical neoplasms: which fits better with patient's outcome?

F. Ambrosi^*, G. Santandrea, A. De Leo, B. Corti, C. Ceccarelli, V. Vicennati, G. Zavatta, D. Santini

^*Dept. of Pathology, University of Bologna, Italy

Background & Objective: Oncocytic Adrenocortical Tumours (OATs) diagnostic criteria have been matter of debate. The aim of the study was to compare different scoring systems and correlate them with follow-up.

Method: We reviewed 21 OATs of patients who underwent surgery in our institution from 2007 to 2017. We assessed the Weiss score (WS), Weiss revisited score by Aubert (WR), Linn Weiss Bisceglia score (LWB), Helsinki score (HS), and “reticulin” algorithm (RA). Each score were established with full agreement among five pathologists.

Results: WS classified 57.2% (12/21) as benign and 42.8%(9/21) as malignant; WR 71.4% (15/21) as benign and 28.6 (6/21) as malignant; LWB 52.3%(11/21) as benign, 19.1% (4/21) as “uncertain malignant potential” and 28.6%(6/21) as malignant; HS 80.9% (17/21) as non-metastatic potential vs. 19.1%(4/21) as metastatic potential; RA 42.9% (9/21) as benign with no altered reticulum framework and 28.6%(6/21) with irregularly thickened and frayed fiber vs. 28.6 (6/21) as malignant. In malignant tumours, according to the LWB score, Ki67 presents an average of 12.4%(range:2.7- 18.89). Follow-up information was available for 17/21 patients (mean of 1169 days). None of our court died of disease or showed any signs of local recurrence, two patients (9.5%, 2/17) developed distant metastasis.

Conclusion: LWB downgraded malignant OCTs in contrast to WS and WR; while HS eliminated “uncertain malignant potential” category and seems to better predict patients’ outcome.

PS-03-021

EWSR1 rearrangement is a common molecular alteration in thyroid tumours

J. M. Cameselle-Teijeiro^*, J. Caneiro-Gómez, M. Piso-Neira, E. Couso, R. Pérez-Becerra, M. Sánchez-Ares, I. Abdulkader, C. Eloy, M. Sobrinho Simões

^*Clinical University Hospital, Anatomic Pathology, Santiago de Compostela, Spain

Background & Objective: EWSR1 rearrangements were recently demonstrated by our group as a frequent event in papillary thyroid carcinoma (PTC) and in carcinoma of the thyroid with Ewing family tumour elements (CEFTE). We have looked for EWSR1 rearrangements in different types of follicular derived thyroid tumours.

Method: Fluorescence in situ hybridization (FISH) technique was performed on 4-μm paraffin embedded tissue sections from: 1 follicular adenoma (FA), 4 hyalinizing trabecular adenomas (HTA), 12 PTCs, 1 follicular carcinoma (FC), 3 Hürthle (oncocytic) carcinomas (OC) and 5 anaplastic (undifferentiated) carcinomas (AC). FISH was carried out using Vysis EWSR1 Break Apart FISH Probe (Abbott Molecular, Illinois, USA) and Vysis RET Break-Apart FISH Probe (Abbott Molecular). In each case, 50 nuclei were scored for the presence of EWSR1 and RET rearrangements. Cases were considered positive for EWSR1 rearrangement and/or RET rearrangement when 5% or more of the nuclei with the break-apart signal were detected, respectively.

Results: Positivity (in percentage) for EWSR1 rearrangements was detected in 1/1 FA (26%); 4/4 HTAs (6%, 13%, 28% and 34%); 9/10 PTCs (4%, 6%, 13%, 17%, 17%, 24%, 25%, 32%, 33%, 42%); 1/3 OCs (0%, 3%, 16%); and 4/4 ACs (6%, 14%, 19%, 22%). No RET rearrangements were detected.

Conclusion: Although more studies with a greater number of cases are necessary, our results suggest the participation of EWSR1 rearrangements in the tumourigenesis of different thyroid tumour histotypes. The existence of a roughly similar percentage of these rearrangements in well-differentiated and anaplastic thyroid carcinomas does not mean that they play a role in tumour progression.

Grant PI15/01501-FEDER, ISCIII.

PS-03-022

Clinical utility of EZH1 mutations in the diagnosis of follicular-patterned thyroid tumours

C. K. Jung^*, Y. Kim, S. Jeon, K. H. Jo, S. Lee, J. S. Bae

^*Seoul St. Mary's Hospital, Dept. of Pathology, Republic of Korea

Background & Objective: Follicular-patterned tumours of the thyroid gland are characterized by a predominantly follicular growth pattern. They frequently harbor RAS mutations, not BRAF mutations. Technological advances in molecular testing have discovered novel RAS-type mutations. However, clinical significance of these mutations remains unknown.

Method: We investigated the prevalence and clinical impact of mutations of BRAF, NRAS, HRAS, KRAS, EZH1, EIF1AX, and TERT genes by Sanger sequencing in a series of 201 follicular-patterned thyroid tumours including follicular adenoma (n=40), Hürthle cell adenoma (n=54), noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP; n=50), follicular thyroid carcinoma (FTC; n=40), Hürthle cell carcinoma (n=10), and poorly differentiated thyroid carcinoma (PDTC) arising in a well differentiated follicular neoplasm (n=7), and 120 classic papillary thyroid carcinoma (PTC).

Results: Two hot spots of EZH1 mutations were only found in in RAS-negative follicular-patterned tumours. EZH1 mutations were detected in 3% of follicular adenoma, 20% of Hürthle cell adenoma, and 10% of minimally invasive Hürthle cell carcinoma. Thyroid tumours with EZH1 mutations reported in the literature were benign in most cases. Otherwise they were minimally invasive or non-invasive thyroid cancer on histologic examination. EIF1AX mutation was found only in one follicular adenoma. We confirmed the presence of RAS mutations and BRAF K601E mutation in benign, borderline, and malignant follicular-patterned tumours. No BRAF V600E was found in 201 follicular-patterned tumours. This study also confirmed the occurrence of TERT promoter mutations in high-risk thyroid cancers.

Conclusion: These genetic markers can be used for the diagnostic purpose and risk stratification of thyroid nodules.

PS-03-023

Predictive factors for malignancy and recurrence in ovarian goiter: a case series of 56 patients

S. Nasr^*, R. Tahri, P. Duvillard, S. Leboulleux, H. Sheikh Alard, M. Schlumberger, J. Y. Scoazec, A. Al Ghuzlan

^*Institut Gustave Roussy, Pathologie Médicale, Villejuif, France

Background & Objective: Ovarian goiter (OG) is a mature teratoma composed predominantly of thyroid tissue (>50%) disclosing the same spectrum of histologies of thyroid gland. Malignant ovarian goiter (MOG) represents 0.01% of ovarian tumours and 5 to 10% of OG. Mixed tumours with thyroid and carcinoid components are called strumal carcinoid (SC) and are potentially malignant. Because of its rarity, diagnostic criteria and treatment are not consensual. Objectives: To better classify OG according to criteria for high-risk progression and relapse in order to treat them appropriately. To examine whereas criteria of malignancy for thyroid primitive tumours were also applicable in cases of OG and whether they are predictive of outcome and relapse.

Method: A pathological and clinical review of 56 cases of OG diagnosed at Institut Gustave Roussy over 17 years was done. Tumours were classified according to the 2017 WHO classification system.

Results: 56 cases: 18 benign OG, 22 SC and 16 thyroid carcinomas of various types. Overall survival was 100% at 5 years with a median follow-up of six years (no documented disease-associated- death). Recurrence occurred in 2 of 4 cases with capsular rupture and both cases with peritoneal or ovarian implants. The only distant metastatic case was of neuroendocrine component.

Conclusion: This is the second largest series of OG. Histologic classification of thyroid malignancy did not affect overall survival or tumour progression. Factors predictive of recurrence seem to be ovarian capsular rupture which correlates with a lesion size of >10 cm, presence of peritoneal implants and presence of a neuroendocrine component.

PS-03-024

Papillary thyroid microcarcinoma: the rate of lymph node metastasis

S. Rjabceva^*, M. Fridman, Z. Bragina, S. Mankovskaya

^*Belarussian State Medical University, Pathology, Minsk, Belarus

Background & Objective: Papillary thyroid microcarcinoma (PTMC) is defined as a malignancy sized up to 1 cm that often diagnosed accidentally. The aim of this study was to analyze the frequency of lymph node metastasis (LNM) in patients with this disease in the post-Chernobyl fallout area.

Method: Patients (n=122) with PTMC were admitted to the hospital during January to March 2015 for treatment with total thyroidectomy (all of them) and simultaneous lymph node neck dissections (91.2%).

Results: It was men to women ration as 1:4 (26/21% and 96/79%, correspondingly). The age of patients ranged from 16 to 93 years, the average age was 47.6 years (47.7 – for women and 46.9 – for men). PTMC size ranged from one to 10 mm, microscopic extrathyroid extension to the fat tissue was detected in 74/60.7% cases. Tumours were monofocal (110/90.2%) and bilateral (12/9.8%). Solitary lesions commonly located in the right (65/59%) or left (33/30%) lobes and rarely in the isthmus (12/11%). Nodal disease was detected in 49 (40.2%) patients: 24 patients had N1a, 25 - N1b.

Conclusion: More than 40% of patients with papillary thyroid microcarcinomas had the LNM at presentation. Surgical treatment of PTMC should not differ from the management of more sizable papillary thyroid carcinoma.

Sunday, 9 September 2018, 09:30 - 10:30, Exhibition Hall I/II

PS-04 | Gynaecological Pathology

PS-04-001

Universal Lynch syndrome screening in endometrial cancer: two years of experience

S. D. Carvalho^*, J. Pardal

^*Hospital de Braga, Pathology, Portugal

Background & Objective: Lynch syndrome (LS) is an autosomal dominant cancer susceptibility syndrome characterized by increased risk for developing several cancers. Endometrial carcinoma (EC) is the sentinel cancer in >50% of women. Recently, universal screening for patients with EC has been advocated but still lacks consensus. We prospectively implemented universal LS screening in our institution.

Method: From 1 January 2016 to 31 December 2017, in all patients with endometrial carcinoma a four-antibody panel immunohistochemistry (IHC) for MLH1, PMS2, MSH2 and MSH6 was performed. The complete absence of nuclear staining in tumour cells for one or more markers was deemed indicative of mismatch repair (MMR) deficiency. All patients with any pattern of MMR loss were offered germline mutation testing.

Results: 35 patients were screened (mean age of 72years). 10 (28,6%) presented abnormal MMR IHC: 5 showed dual loss of MLH1/PMS2, 1 dual loss of MSH2/MSH6, 2 isolated loss of PMS2 and 2 isolated loss of MSH6. 8 accepted germline mutation testing. 2 (5,7%) were confirmed to have LS, 1 with germline MSH2 and 1 with germline MSH6 mutation. Only 1 of these patients would have been identified if LS-associated clinical data and morphologic features had been applied.

Conclusion: Besides the still small number of patients, our results are concordant with previous similar studies and support the universal screening of Lynch syndrome (LS) in patients with endometrial carcinoma given the proportion of patients that would have been missed with strategies that rely only on Revised Bethesda Guidelines.

PS-04-002

Uterine tumour resembling ovarian sex cord tumour with granulose-like differentiation - a case report

A.-S. Varban^*, A. Curte, C. L. Gîrbea, A. Poteca, C. Paranici, V. Enache, S. Enache, I. Salem, I. A. Ostahi, O. M. Andreoiu, M. Comanescu, F. Andrei

^*Emergency University Hospital, Pathology, Bucharest, Romania

Background & Objective: Uterine tumours resembling ovarian sex cord tumours (UTROSCT) represent an extremely rare type of neoplasms (< 0,5% of all uterine malignancies). Etiology is uncertain, but there are many theories: derivation from uncommitted mesenchymal stem cells or from ovarian sex cord cells which have been displaced during embryogenesis, overgrowth of sex cord elements within endometrial stromal neoplasm or adenosarcoma. They can be mistaken for leiomyomas, because of the similar symptomatology (menorrhagia, pelvic pain, pressure).

Method: We report a case of a 46-year old woman who presented to our hospital for menorrhagia. The clinical diagnosis was uterine leiomyoma. She then underwent total hysterectomy with bilateral adnexectomy. The specimen was sent to our Pathology Department for histopathological examination.

Results: Macroscopic examination revealed two uterine nodules: a 35 mm whitish, firm subserosal nodule, which was microscopically confirmed as a leiomyoma, and a 70 mm, well-circumscribed, yellowish, soft intramural nodule. Microscopy of the second nodule showed a rather well circumscribed proliferation of small cells, with monomorphic, vesicular nuclei, forming a microfollicular pattern. Differential diagnosis included: leiomyomas (different subtypes), endometrial stromal tumour and endometrioid carcinoma with sex cord-like features, adenosarcoma. In order to establish a positive diagnosis, immunohistochemical stainings were performed: sex cord markers (calretinin, inhibin, melan A - negative; CD 56 - positive); PR, vimentin, WT1 - positive; AE1/AE3, ER, CK 7, PAX 8, CD 10, EMA - negative.

Conclusion: UTROSCT is very rare finding in uterine specimens. Particularities of this case are granulosa-like morphology with microfollicular pattern and coexistance with a leiomyoma.

PS-04-003

An adenocarcinoma of mammary-like glands of the vulva presenting with inguinal adenopathy: a case report of a rare entity

S. Lerias^*, J. Ferreira, A. Félix

^*IPOLFG, Serviço de Anatomia Patologica, Lisboa, Portugal

Background & Objective: Adenocarcinoma of mammary-like glands (MLG) of the vulva is an extremely rare entity derived from anogenital MLG. To the best of our knowledge, less than 30 cases have been reported.

Method: We report a case of a vulvar adenocarcinoma of MLG presenting with left inguinal metastasis.

Results: A 53-year-old female presented with weight loss and left inguinal lymphadenopathy. A complete PET-CT scan revealed no additional lesions. The lymph node was excised and pathological examination was consistent with a metastatic CK7 positive adenocarcinoma. Clinical observation, including mammary and gynaecological examination, was unremarkable. Endoscopy and imaging studies, including mammary and gynaecological MRI, were normal. Six months later, a small nodule in the vulvar labium minor was detected in the gynaecological evaluation and biopsied. Histological examination revealed an infiltrating solid and tubular adenocarcinoma located in the lamina propria with no connection to the epithelium. The cells had large, pleomorphic nuclei with prominent nucleoli. Pancytokeratin AE1/AE3, cam5.2, CK7, GATA3, GCDFP-15 and mammaglobin were positive. Estrogen and progesterone receptors were negative. Retrospectively, additional immunohistochemical stains (GATA3, mammaglobin and GCDFP-15) were performed in the lymph node and were positive. Immunohistochemical staining for ERBB2 was positive (+3) in both the primary and the metastatic lesions. The diagnosis of an adenocarcinoma of MLG of the vulva with a lymph node metastasis was established.

Conclusion: Adenocarcinoma of the MLG of the vulva is a rare entity. Its diagnosis, namely in the metastatic setting, requires a high level of suspicion and clinical and imagiological correlation.

PS-04-005

CADM1, MAL and miR-124 promoter methylation as biomarkers of progression in cervical cancer

A. Sierra Gomez^*, L. Marimon, A. Rodriguez-Trijillo, C. Marti, E. Barnadas, A. Torne, M. del Pino, J. Ordi

^*H. Clinic, Pathology, Barcelona, Spain

Background & Objective: Molecular tests for hrHPV detection have shown a sensitivity of 90-95% for the detection of high-grade intraepithelial lesions/cervical intraepithelial neoplasia grade 2-3 and CC (HSIL/CIN2+), but have a relatively low specificity, as many hrHPV infections will never progress to CC. This prospective study analyzes whether the CADM1, MAL and miR124 promoter methylation analysis could detect those patients with HSIL/CIN2+, and thus, have a role in the triage of hrHPV-positive women.

Method: Prospective study that included cervical biopsies form 131 women referred to the Colposcopy Clinic from January 2013 to December 2015. Eight patients had a negative biopsy and were negative for hrHPV, 19 had a low-grade squamous intraepithelial lesion/cervical intraepithelial neoplasia grade 1(LSIL/CIN1), 30 had HSIL/CIN2, 60 a HSIL/CIN3, and 14 a cervical cancer (CC). DNA extraction was performed from formalin-fixed paraffin-embedded tissue after bisulfite treatment. A standardized, multiplex quantitative methylation specific PCR was used to identify the methylation status of the promoter regions. The proportions of methylation-positive samples per histological diagnosis were compared using the Mann-Whitney U test.

Results: DNA methylation of at least one loci was detected in 12,5% (1/8) of normal samples, 31.5%(6/19) of LSIL/CIN1, 83.3%(25/30) of HSIL/CIN2, 81.6%(49/60) of HSIL/CIN3 and 100%(14/14) of the CC (p= <0.001). miR124 and MAL were the most frequent methylated loci in HSIL/CIN2+ (66.6% and 56.6% for HSIL/CIN2; 68.3% and 60% for HSIL/CIN3; and 92.8% and 78.5% for CC, respectively). Methylation of CADM1 was the most specific for the detection of HSIL/CIN2+ and HSIL/CIN3+ lesions, whereas miR124 was the most sensitive.

Conclusion: CADM1, MAL and miR-124 promoter methylation could be a useful biomarker of progression in women with hrHPV associated cervical lesions.

PS-04-007

Primary retroperitoneal borderline mucinous cyst of Mullerian origin - a case report

C. Paranici^*, A.-S. Vârban, F. Andrei, C.-L. Gîrbea, I. Ahmed Salem, M. Sajin, A. Curte

^*Elias Emergency Hospital, Bucharest, Romania

Background & Objective: Retroperitoneal mucinous cysts are extremely rare, mostly occurring in women. Our objective is to present a new case of a retroperitoneal borderline mucinous cyst of Mullerian origin.

Method: A 38-year-old woman, with a history of laparoscopic surgery performed 3 years ago for a benign retroperitoneal cyst in the left hypochondrium, was admitted to our hospital for tumour recurrence. Another laparoscopic intervention was performed with incomplete excision due to adherence to the left colon wall. No lesion was observed in the ovaries, fallopian tubes, pancreas or kidneys.

Results: The specimen was composed of multiple fragments of cyst wall measuring 80/75/7 mm, with a smooth, white-greyish surface, and a 7 mm diameter white nodule. Histopathological findings revealed a densely fibrotic cystic wall, lined by a single layer of columnar cells with areas of nuclear atypia, either nuclear enlargement or vesicular nuclei. The nodule showed glands lined by a mucinous epithelium of endocervical-type, with intraluminal projections, some with a more complex architecture, lined by stratified, enlarged, hyperchromatic nuclei. The nodule stroma had an “ovarian-like” pattern and was composed of spindle cells with little cytoplasm and indistinct borders. Immunohistochemistry confirmed the Mullerian origin.

Conclusion: This is a very uncommon case of a retroperitoneal mucinous cyst of Mullerian origin. The particularities of this case are the borderline aspect, resembling ovarian mucinous tumours and the “ovarian-like” stroma. Close adherence to surrounding structures prevented the complete excision of the cyst, leading to a recurrence. Open surgery was proposed to the patient and will probably follow.

PS-04-008

Mesothelial cyst of round ligament of uterus presenting as inguinal hernia in a young female – a case report

C. Paranici^*, A.-S. Vârban, F. Andrei, C.-L. Gîrbea, I. Ahmed Salem, M. Sajin, A. Curte

^*Elias Emergency Hospital, Bucharest, Romania

Background & Objective: Cysts of the round ligament of the uterus are a very rare finding. The literature reveals 10 cases of mesothelial cysts between 1980 and 2013. They are usualy misdiagnosed as inguinal hernias or adnexal masses and occur in women in their late third or fourth decade. Our objective is to present a new case of a round ligament cyst of the uterus.

Method: A 29-year old female patient presented at Elias Hospital with a groin mass. The clinical diagnosis was of incarcerated right inguinal hernia, for which the patient underwent surgery.

Results: We received a specimen consisting of a greyish mass surrounded by fat, measuring 30/15/10 mm, with elastic consistency, a cystic apearance on serial sections, and containing a clear liquid. Histology showed the cyst was lined by a monolayered flatened epithelium, with areas of cuboidal cells. The cyst presented focal areas of moderate lymphoplasmacytic and neutrophilic inflamation, congestion and reactive epithelial cells, and was surrounded by a fibrocollagenous stroma including smooth muscle fibers, fatty tissue, dilated blood vessels and some nerve fascicles and striated muscle fibers at the periphery. We perfomed immunohistochemistry to distinguish between a mesothelial and a serous origin. Calretinin, vimentin, and WT1 were positive and EMA was negative, thus confirming the mesothelial origin of the cells.

Conclusion: Although it is such a rare encounter, a mesothelial cyst of the round ligament should be included in the differential diagnosis of other groin masses in women such as inguinal or femoral hernias, lipomas or hydrocele of Nuck’s canal (Nuck’s canal cyst).

PS-04-009

Immunohistochemistry for detecting colorectal (CRC) and endometrial cancer (EC) patients at risk for Lynch Syndrome (LS). Utility of a 2-antibody panel

A. Wernicke ^*

^*Hospital Italiano de Buenos Aires, Anatomia patologica, Argentina

Background & Objective: Currently, testing for mismatch repair deficiency proteins (MMR-P) in CRC and EC is initiated by performing IHC with a 4-antibody panel (MLH1, PMS2, MSH2 and MSH6). Due to the binding properties of the MMR heterodimer complexes, gene mutation and loss of MLH1 and MSH2 invariably result in the proteolytic degradation of their obligatory partners PMS2 and MSH6, but not conversely.

Method: To analyze the expression of MMR-P by IHC in patients with CRC and EC. We propose that a 2-antibody panel (PMS2 and MSH6) can be sufficient to detect cases of MMR-P expression deficiency.

Results: We collected 2 cohorts of CRC and EC patients from the records of our institution: (1) A retrospective series of 200 unselected patients with CRC and (2) a prospective series of 108 unselected patients with EC. In all cases, a 4-antibody panel was performed.

Conclusion: Of the 308 tumours tested, 65 (21%) showed abnormal staining for at least one MMR-P: 51 cases (78.5%) showed concurrent loss of expression of MLH1 and PMS2, 3 (4.5%) concurrent loss of MSH2 and MSH6, 4 (6%) loss of PMS2 alone, and 7 (11%) loss of MSH6 alone. No cases showed isolated loss of expression of MLH1 or of MSH2. CONCLUSION: Our findings suggest that a 2-antibody panel is as effective as the current 4-antibody panel in detecting MMR-P abnormalities. This approach has cost-effective implications for an IHC panel that is being widely used as the first line of screening for LS.

PS-04-010

c-KIT immunohistochemistry and KIT mutational status in mesonephric carcinomas of the female genital tract

J. Pors^*, J. Ho, L. Prentice, B. Gilks, L. N. Hoang

^*Vancouver General Hospital, Dept. of Anatomical Pathology, Canada

Background & Objective: Mesonephric carcinoma is a rare gynaecological malignancy. Approximately one-third of patients will suffer from local recurrence or distant metastases. To date, no targeted therapeutic options have been identified. Based on limited case reports, c-KIT immunohistochemical expression has been reported in female adnexal tumours of Wolffian origin (FATWO), and targeted therapy with imatinib has been attempted with mixed success. Currently, it is unclear whether c-KIT immunohistochemical expression is seen in mesonephric carcinomas and how this correlates with KIT mutational status.

Method: Using whole sections, we assessed the immunohistochemical expression of c-KIT in a series of 11 mesonephric carcinomas of the female genital tract (5 cervical, 3 uterine corpus, 1 ovarian, 1 broad ligament, 1 pelvic tumour). The intensity of staining and proportion of cells showing cytoplasmic/membranous staining were recorded. Plasma cells served as an internal control. KIT was sequenced using a next generation sequencing panel which targets 120 hotspots and 17 exons in 33 known actionable cancer genes. This panel includes exons 9, 11 and 13 of KIT, and 6 hotspots (T670, D816, D820, N822, Y823, A829).

Results: c-KIT immunohistochemical expression was observed in the vast majority of mesonephric carcinomas, 9 of 11 cases (82%). Staining was moderate to strong in intensity and ranged from 5% to 80% of cells (average 34%). DNA has been extracted and the KIT molecular results are pending.

Conclusion: c-KIT immunohistochemical expression was observed in a large number of mesonephric carcinomas. KIT mutational results will be known shortly, allowing us to assess whether c-KIT immunoexpression correlates with mutational status.

PS-04-011

Morphological substrate and molecular mechanisms of pregnancy failure in women with undifferentiated connective tissue dysplasia (uCTD) and hereditary thrombophilia (HT)

T. Demura^*, E. Kogan, A. Zanozin, D. Kolossovskiy

^*Sechenov University, Anatomic Pathology, Moscow, Russia

Background & Objective: HT and uCTD seem to have general pathogenesis and may lead to infertility. The aim of the study: to determine the morphological substrate and molecular mechanisms of pregnancy outcomes violations in women with uCTD and HT.

Method: 130 patients of reproductive age women with primary infertility (main group) and 11 patients of control group (surrogate mothers). Patients of the main group were divided into subgroups: 1A - with infertility and HT (91), 1B with infertility, HT and uCTD (19), 1B - with infertility and uCTD (20). Endometrial biopsy specimen was taken on the 6-8 day after ovulation with following morphological and immunohistochemical study with primary antibodies to LIF, PAI-1, osteopontin. Blood samples were taken in subgroups 1A and 1B for PAI-1 and homocysteine, methionine test; polymorphisms of: FII, FV (Leiden), FVII, FXII, FXIII, GpIa, GpIb (5), GpIb (T145M), GpIIIa, PAI-1, FBGb, MTHFR, MTRR, MTR, SLC19A1, angiotensinogen M235T and T145M, angiotensin-converting enzyme, homo- or heterozygosity.

Results: The most favorable outcomes were observed in subgroup 1B, least - in 1A. we revealed significant differences in hemostatic system only in the frequency of disaggregated thrombopathy development - 88% in group 1B and 55% in group 1A. There was slowing of endometrium maturation with decreased expression of LIF, PAI-I and osteopontin in main group.

Conclusion: In patients with HT, uCTD, and more with combination of HT and uCTD genetically determined predisposition to impaired implantation develops, due to remodeling of the endometrium, leading to the development of infertility and violation of pregnancy outcomes.

PS-04-012

Extragenital neoplasias involving the uterine cervix: a case series of diagnostic biopsies

B. Machado^*, V. Ferreira, C. Bartosch

^*IPO-Porto, Pathology, Maia, Portugal

Background & Objective: Involvement the uterine cervix by extragenital neoplasia is a rare event. Diagnostic challenges ensue from the small size of biopsies and the fact that many primary tumours have been reported to metastasize to the cervix. We aimed to describe a case series of cervix biopsies diagnostic of secondary involvement.

Method: We retrospectively (2012–2017) identified twelve patients with involvement of the uterine cervix by extragenital neoplasias diagnosed in biopsies. Clinical files and histological material were reviewed.

Results: Median patient age was 70 years (range:42-89). Pathological findings were consistent with cervix metastases from tumours originating in gastrointestinal tract (n=7) and breast (n=4). These included 3 poorly cohesive adenocarcinomas and 3 lobular carcinomas, respectively, frequently showing signet ring morphology. Additionally, involvement of the cervix by a diffuse large B-cell lymphoma was also found. Biopsies were usually limited to small tissue fragments, ranging from 3 to 10mm. Immunohistochemistry study was done in the majority of cases (n=10), using a large panel (mean of 6 antibodies). In five patients the primary tumour was previously known (mean of 7 years prior). Cervix involvement was the first histologic diagnosis of an extragenital primary neoplasia in the remaining patients. Almost all patients (n=10) had widespread disease at the time of cervical biopsy.

Conclusion: Carcinomas of the gastrointestinal tract and breast, frequently with signet ring morphology were the more common metastases from an extra-genital site involving the cervix. Combining all clinical and pathological data is essential for a correct final diagnosis.

PS-04-013

Villoglandular adenocarcinoma of the vulva: case report and literature review

I. González Villa^*, I. Expósito Afonso, A. Vega Falcón, L. I. Martínez Blanco, R. Méndez Medina

^*Hosp Universitario de Canarias, Anatomía patológica, La Laguna, Spain

Background & Objective: Primary adenocarcinomas of the vulva are rare entity. Within them, the intestinal subtype (known as villoglandular adenocarcinoma, cloacogenic carcinoma or cloacogenic adenocarcinoma) is an exceptional finding. These tumours share morphological features with colon adenocarcinomas. Villoglandular adenocarcinomas may originate from cloacal remnants but the mechanisms of development of this vulvar mucinous lesion are controversial.

Method: We present a case of villoglandular mucinous adenocarcinoma of the vulva in a 56-year-old patient with no relevant medical history. A partial vulvectomy was performed in which a brownish-colored papillary-excrescent lesion measuring 2.5 x 1.7 cm was observed. In microscopic findings, we identified a branched villous-papillary lesion with 2 mm invasion formed by atypical pseudostratified cylindrical cells with interspersed goblet cells. Immunostains (IHC) and PAS stains were performed.

Results: Globet cells were PAS positive and tumoural cells showed strong and diffuse positivity for CK20 and CDX2 markers and CK7 and estrogen receptors were negative.

Conclusion: The exact mechanism of the development of intestinal tumours in the female genital tract is not known. Several reports support the hypothesis that intestinal neoplasia of the vulva could develop from cloacal remnants. We present a case of an exceptional entity in the vulva with IHC CK7-/CK20+, which could support this hypothesis.

PS-04-014

Endometrial changes related to long term use of the levonorgestrel releasing intrauterine system

D. Menezes^*, F. d. Chagas Medeiros, R. H. Carvalho Neto, M. A. Paiva, R. Vasconcelos, E. Teles, M. Pimentel

^*Faculdade de Medicina da UFC, DPML, Fortaleza/Ceará, Brazil

Background & Objective: Those who have been practicing diagnostic pathology for half a century, in keeping with knowledge and morals of the time, have been noticing changes in the structure of organs, due to therapeutics. We decided to study the endometrial changes owing to the insertion of the so called levonorgestrel-releasing intrauterine system.

Method: 25 samples of endometrium, of a period of six months until March 2018, after 5 years of implantation of levonogestrel, when removed to be replaced. Patients´ ages ranged from 28 to 51; two categories, a younger purposed for contraception (5), ages around 40-50 meant chiefly for functional disturbances (20). Biopsies done during hysteroscopy, Specimens stained with H&E and immunohistochemistry: CD138 for plasma cells (2)

Results: Hypotrophy; micropolypoid indentations; pre/pseudodecidualized stroma; large cells, with slightly eosinophilic cytoplasm, intermingled with spindled vacuolated ones; myxoid degeneration; foci of crowded small round cells, including plasma cells; glands lined by cells with infra and supranuclear vacuoles, also fully secretory; atrophic, lined by flattened epithelium, often cystic; rarely, oxyntic metaplasia. Vessels forming aggregates, as of granulation tissue; deposits of fibrin; coarse deposits of calcium salts.

Conclusion: Iatrogenic deviation from normal predecidual/decidual aspects, interpreted as result of continuous stimulation by gestagens, without a proliferative phase, and of inflammation. One should speculate about what comes next, if the patient decides to no longer use the device, envisaging fertility. What the consequences will be of so prolonged use of instilled gestagens. Furthermore, consequences, in the long run, of the persistent stimulation by pituituary hormones, with no due response by the effector organs

PS-04-015

Uterine leiomyoma with diffuse perinodular hydropic degeneration, focal symplastic change and adjacent myometrial hydropic change: unique features of a rare variant of a common tumour

J. C. Nagaputra^*, I. Busmanis

^*Singapore General Hospital, Anatomical Pathology, Singapore

Background & Objective: Leiomyoma is a common tumour of the uterus with a wide spectrum of histological appearances. Although hydropic degeneration within a leiomyoma is not uncommon, accumulation of oedema fluid around the fascicles of neoplastic smooth muscle bundles is rare and gives rise to an unusual variant known as perinodular hydropic degeneration in leiomyoma (PHDL). Concurrent focal symplastic change within PHDL and hydropic changes in adjacent non-neoplastic myometrium have not previously been described. The recognition of PHDL with symplastic change is crucial as it may mimic other uterine disorders, such as myxoid leiomyosarcoma or intravenous leiomyomatosis.

Method: We report a 46-year-old Chinese woman who presented with abnormal uterine bleeding. Magnetic resonance imaging of the pelvis showed a large mass within the anterior myometrium with cystic changes and a heterogenous appearance, suspicious for a uterine sarcoma. Total hysterectomy and bilateral salpingectomy were performed.

Results: Grossly, a large, relatively circumscribed tumour, which consisted of multiple pale fleshy nodules separated by oedematous connective tissue, was seen in the anterior myometrium. Histologically, the nodules comprised intersecting fascicles of smooth muscle cells separated by oedematous, hypocellular fibroconnective stroma. Foci of symplastic change characterised by nuclear enlargement, hyperchromasia and pleomorphism without mitotic activity were discerned. Hydropic change was also seen in the adjacent non-neoplastic myometrium. No dissecting tumour satellite nodules were evident. Alcian blue mucin stain was negative.

Conclusion: PHDL with symplastic change and hydropic change in adjacent normal myometrium is an extremely rare variant of uterine leiomyoma that has not been described in the literature. Its recognition is important as it may mimic malignant lesions of the uterus both radiologically and histologically.

PS-04-016

Characteristics of the niche of uterus fibroid stem cells in simple and lypoleiomyomas

E. Kogan^*, T. Demura, N. Jarkov, N. Zharkov

^*Sechenov University, Anatomic Pathology, Moscow, Russia

Background & Objective: The modern concept of uterus fibroids (UF) development is based on arising from fibroid tumour stem cells located in special niche in tissue. Aim to characterize a possible niche of tumour stem cells in UF.

Method: biopsy and operative material of 54 patients 27-55 years old with simple type UF and 12 patients with lypoleiomyomas (LLM) were analyzed. Patients were divided in two groups: with large leiomyomas, more than 6 sm in diameter (30 patients) and control with UF and LLM, less than 4 cm in diameter (24). Immunohistochemistry (IHC) with semiquantative analysis determined the expression of nestin, connexin, CD117, PD-ECGF TGFβ, Ki67, Vimentin.

Results: IHC showed increased expression of nestin, connexin, CD117, PD-ECGF TGFβ, , Ki67, Vimentin in separate cells of perivascular growth zones in UF and LLM. Cells with expression of nestin, connexin, CD117, TGFβ, Vimentin may be considered stemless cells. It was found that LLM commonly contained adipocytes adjacent to stemless cells not only in the perivascular region, but also in the foci of adipose tissue inside tumour parenchyma.

Conclusion: Niche of tumour stem cells in simple UF and LLM are localized in the perivascular regions of UF and LLM and are characterized by the presence of stemless cells inside them, that is shown in the enhancement of expression of the stem cell markers - nestin, connexin, CD117, PD-ECGF TGFβ, Vimentin. Adipocytes in LMM in perivascular zone also may be considered as potential markers of tumour stem cells niche.

PS-04-017

Clinicopathologic features of colonic endometriosis simulating colon neoplasia

S. Petronilho^*, M. Farinha, D. Gigliano, R. Vieira, C. Bartosch

^*IPO-Porto, Pathology, Portugal

Background & Objective: Endometriosis is frequent among pre-menopausal women. Colonic endometriosis accounts for most extra-pelvic cases and may clinically simulate colon neoplasia. We aimed to describe the clinicopathological features of colonic endometriosis clinically simulating colon neoplasia.

Method: We retrospectively (2007-2017) identified three patients with colonic endometriosis diagnosed in resection specimens, with a pre-surgical presumptive diagnosis of colon neoplasia. Clinical and imagiological records were retrieved from the patients’ files and histological features were reviewed.

Results: All three patients were pre-menopausal, nulliparous women, presenting with abdominal pain. Imaging and endoscopic studies showed a stenosing colonic lesion in two patients and in the third patient colonic mass concomitant to a left ovarian tumour. Pre-surgical biopsies only denoted non-specific inflammatory colitis. The patients underwent surgery under presumptive diagnoses of primary colon neoplasias and secondary involvement by ovarian tumour. Intraoperatively, inspection of the abdominal cavity raised suspicion of pelvic peritoneal endometriosis in two cases. Perioperative pathological examination excluded primary colon malignancy in all patients. Macroscopically, the lesions were described as subserosal/submucosal masses or colonic wall thickening, and the mucosa was grossly spared. Microscopic examination was diagnostic of colonic endometriosis, showing endometrial glands and stroma infiltrating the serosa/subserosa, muscularis propria and, in two cases, focally reaching the mucosa. All cases had lymph node involvement. The third patient had a concomitant diagnosis of synchronous endometrioid ovarian and uterine carcinomas, with loss of expression of MSH6.

Conclusion: Diagnosing colonic endometriosis is clinically challenging. Peri-operative examination should be considered when the clinical picture is unclear, as it may prevent overtreatment.

PS-04-018

Expression of VEGF and SOD3 in the placenta of pregnant women with breast cancer

A. Shchegolev^*, R. Shmakov, M. Volochayeva, U. Tumanova, G. Sukhikh

^*NMRCOGP, Pathomorphology, Moscow, Russia

Background & Objective: To study the expression of VEGF (vascular endothelial growth factor) and SOD3 (superoxide dismutase-3) by immunohistochemical methods in the placenta of pregnant with breast cancer (BC).

Method: Studied 45 placentas: group I - placentas from women who had BC diagnosed during pregnancy but did not receive treatment (n=11), group II - placentas from women who received BC-chemotherapy during pregnancy (n=19), group III (control) - placentas from puerperas with-out pathology (n=15). Performed a morphological study of the placentas and quantitative analy-sis of immunohistochemical reactions of VEGF and SOD3 in syncytiotrophoblast (STB) and endothelium of capillaries (EC) in terminal villi.

Results: The lowest VEGF expression in STB were found in group I (10.9% and 20.5% less than in group II and III, respectively). The minimum value of VEGF in the EC were in group II (30.4% and 23.0% less than the values of groups III and I, respectively). The lowest SOD3 expression was in group II (less by 4.6% and 9.6% in STB and by 26.3% and 12.2% in EC compared to groups I and III). The SOD3 expression in the EC of the placenta of group I exceeds the corresponding values of the control group.

Conclusion: Decreased expression of VEGF and SOD3 in terminal placental villi reflects the processes of placental damage at BC and chemotherapy. Multidirectional changes in the intensity of the SOD3 reaction indicate the development of compensatory reactions aimed at neutralizing the increased intake of oxygen radicals.

PS-04-019

Evaluation of platelet to lymphocyte and neutrophil to lymphocyte ratios as potential biomarkers of endometrial pathology in postmenopausal women

Z. Tsakiraki^*, V. Pergaliotis, A. Zacharatou, A.-R. Gouloumis, E. Panopoulou, S. Konstantoudakis, A. Pouliakis, V. Damaskou

^*NKUA, School of Medicine, "Attikon" University Hospital, 2nd Dept. of Pathology, Athens, Greece

Background & Objective: Systemic low-grade inflammation has been investigated extensively in the field of cancer the last years. Neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte (PLR) ratios seem to be promising markers and have been previously reported in various tumours. The purpose of the present study is to investigate if these ratios differ in postmenopausal patients with evidence of endometrial pathology. A significant contribution is that it is based on a significantly larger cohort compared to previous evidence in the field.

Method: We retrospectively searched patient records and identified postmenopausal patients with evidence of endometrial pathology (vaginal bleeding or endometrial thickness ≥ 5 mm determined by ultrasound examination). The study based on a cohort of 178 patients that underwent dilatation and curettage between January 2013 and December 2016. The statistical analysis was performed with the IBM SPSS statistical package.

Results: Overall, 106 women with endometrial cancer and 72 controls were included in the present study. The total number of white blood cells was comparable between the two groups (6,815 (4,010-16,270) vs 7035 (3,520-15,530) p=.373). Similarly, neither NLR (1.70 (0.27 – 25.79) vs 1.93 (0.71 – 12.18) p=.102) nor PLR (0.12 (0.02 – 1.51) vs 0.12 (0.05 – 0.69) p=.767) differed between patients with benign endometrial pathology and those with endometrial cancer.

Conclusion: Our study suggests that neither PLR nor NLR may serve as potential markers for the prediction of endometrial cancer. However, future cohorts are needed to elucidate this field

PS-04-020

Uterine adenosarcoma: a case report and literature review

J. C. Melo^*, D. N. Oliveira, G. B. dos Santos Ponte, R. M. Colares, E. R. de Lemos, L. M. Marques, P. V. Pereira Motoyama, S. A. de Souza Júnior, D. I. Magno Cavalcante, T. N. Albuquerque Gomes, D. N. de Melo Braga

^*University of Fortaleza, Graduate Programme, Brazil

Background & Objective: Uterine adenosarcoma is a rare mixed tumour composed of malignant stromal and benign epithelial elements. It occurs in any age, but it is mainly found in women after menopause. It commonly arises from the endometrium, but in rare cases it may appear in the endocervix and within the myometrium. The diagnosis is based on symptoms, such as vaginal bleeding, pelvic pain or vaginal discharge, and on histopathologic exam. we report a case of a patient diagnosed with uterine adenosarcoma.

Method: Biopsy was made.

Results: A 62-year old female patient presented vaginal bleeding after menopause. An ultrasonography revealed an endometrial mass. A biopsy of the lesion acquired nine soft, elastic, irregular, brown fragments measuring 2.2 × 1.2 × 0.3 cm. Histopathological exam showed low cylindrical glandular or cubic epithelium with either nuclear atypia or evidence of cytoplasmic eosinophilia, or both. The epithelium surrounded the stroma, which was composed of nests of spindle or rounded cells, forming a periglandular belt occasionally, where nuclear atypia is more evident. Mitotic index: two mitotic figures per ten high power fields.

Conclusion: This case showed many of the distinctive characteristics of the rare uterine adenosarcoma, reinforcing that one should consider the diagnosis of adenosarcoma if spindle cells are found in an endometrium biopsy. Its treatment of choice is total hysterectomy with salpingo-oophorectomy. Adenosarcoma has a relatively low malignant potential, if not associated with sarcomatous overgrowth or myoinvasion. Patients with one or both of these features have a less favorable prognosis.

PS-04-021

Clinicopathologic and molecular characteristics of mesonephric adenocarcinoma arising from the uterine body

K.-Y. Na^*, H.-S. Kim

^*Severance Hospital, Dept. of Pathology, Seoul, Republic of Korea

Background & Objective: Mesonephric adenocarcinoma (MNAC) is a rare tumour of the female genital tract mainly occurring in the uterine cervix. To date, only a few cases of MNAC arising from of the uterine body (UB-MNAC) have been reported. The clinicopathologic and molecular characteristics of UB-MNAC remain unknown.

Method: We investigated the clinical, histopathologic, immunohistochemical, and genetic features of UB-MNAC.

Results: In total, 11 cases were included. Six patients developed metastatic disease, most commonly in lungs (5/6). Histopathologically, UB-MNAC was characterized by an admixture of tubular, glandular, papillary, retiform, glomeruloid, sex cord-like, and comedonecrosis-like architectural patterns. Three adverse pathologic characteristics, including advanced International Federation of Gynecology and Obstetrics stage, high mitotic activity, and presence of lymphovascular the invasion, were independent factors predicting the development of metastasis. All cases were positive for GATA-binding protein 3 and paired box 2 expression and showed wild-type p53, patchy p16, and preserved PTEN expression, as indicated by immunohistochemistry. Next-generation sequencing using 12 samples (11 primary tumours and 1 metastatic tumour) revealed 42 single nucleotide variations in 16 genes, mostly in KRAS (10/12) and ARID1A (9/12). Copy number variation was found in 16 genomic regions, and consisted of 57 gains and 10 losses, with 1q gain (11/12) being the most prevalent.

Conclusion: UB-MNAC displays an aggressive biological behavior, with a tendency to metastasize to the lungs. Adverse pathologic characteristics reflect the aggressive nature of UB-MNAC. Distinct molecular features of UB-MNAC include frequent somatic mutations of KRAS and ARID1A and gain of 1q.

PS-04-022

Clinical validation of next generation sequencing for identification of BRCA somatic mutations in high grade serous ovarian carcinoma (HGSoC)

F. Fraggetta^*, S. Vatrano, A. Pettinato, G. Scandurra, G. F. Zannoni, M. Zagami, A. Santoro, P. Scollo

^*Cannizzaro Hospital, Pathology Unit, Catania, Italy

Background & Objective: To establish the feasibility in the clinical practice of targeted next generation sequencing (T-NGS) for BRCAs mutational analysis in order to identifying both somatic and germinal mutations starting from Formalin Fixed Paraffin Embedded (FFPE) tissue.

Method: T-NGS analysis of all coding and flanking intronic regions of BRAC1/2 genes was performed on 17 samples of HGSoC collected at the Cannizzaro Hospital (Catania, Italy). The GeneReaderTM NGS System (GeneRead®QIAact BRCA 1/2 Panel, Qiagen) was the NGS platform used and results were compared with germline analysis previously obtained from corresponding blood samples.

Results: All FFPE cases were genotyped successfully with both good libraries and sequencing CQ metrics. All germline mutations previously identified were confirmed on tumour tissue analysis (concordance 100%) and three of them showed additional somatic alterations, underlying the loss of function of BRCA genes in these patients. Among the three cases without germline variants, two harbored pathogenic somatic mutations (BRCA1_c.80+1G>T; BRCA2_p.N372H) and one presented a silent passenger variant (COSM148280). Most of the genetic variants identified were previously reported in the main mutational databases, except one likely pathogenic and two variants of unknown significance. The diagnostic workflow for T-NGS did not impact in the turn-around time (5 days).

Conclusion: GeneReader NGS is a valuable and feasible tool in molecular testing for somatic BRCA analysis starting from routine tumour tissue. The present study underlines the possibility to assess both somatic and germline mutations form FFPE routine archival material, thus increasing the number of patients suitable for targeted therapy.

PS-04-024

Ki67 expression as prognostic factor in advanced cervical cancer in patients treated with concurrent chemoradiotherapy

R. M. Garcia Martin^*, J. F. Perez-Regadera Gomez, C. Ballestin Carcavilla

^*Hospital 12 de Octubre, Madrid, Spain

Background & Objective: Determine the correlation between Ki67 expression by immunohistochemistry and local failure-free survival (LFFS), progression-free survival (PFS) and overall survival (OS) in a group of patients with locally advanced cervical cancer treated with concurrent chemoradiotherapy

Method: The study was performed in a group of 186 patients with advance cervical cancer (Squamous cell carcinoma 155, Adenocarcinoma 31) treated with chemoradiotherapy The specimens from the cervix before radiation therapy were immunohistochemical stained with Ki67/MIB1 antibody. Patients were stratified according to Ki67 expression in three groups (Group 1 :< 40%, Group 2: 40-70%, and Group 3 :> 70%).

Results: We found that with a Ki-67 / MIB-1 cut-off higher than 40% was more acceptable to identify a highly proliferative tumour. Of the 186 biopsies, 12 (6.45%) were ascribed to the Group 1, 75 (40.32%) to Group 2 and 99 (53.23%) to Group 3. Ki-67 index of 40% or greater correlated significantly with a better response to radiation compared with those with lower expression Low levels of Ki67 were associated with a higher rate of pelvis relapse, decreased progression-free survival (PFS) and overall survival (OS). The survival rate at 3 years for group one was 44%, while for group 2 and 3, 79 and 84% respectively.

Conclusion: The low expression of Ki-67/MIB-1 had significant association with poor prognosis in cervical cancer, both in local failure-free survival (LFFS), progression-free survival (PFS) and global Survival (OS) in patients treated with chemoradiotherapy

PS-04-025

ANXA1 protein overexpression contributes to a good response of ovarian carcinoma to chemotherapy

M. Manai^*, M. Driss, R. Doghri, P. Finetti, R. Bouabsa, D. Birnbaum, K. Mrad, L. Charfi, F. Bertucci

^*Paoli Calmettes Institute, Oncologie Moléculaire, Marseille, France

Background & Objective: Epithelial Ovarian Cancer (EOC) is the highest gynaecological cause of cancer deaths. ANNEXINE A1 (ANXA1) protein has been implicated in aggressiveness of several cancers. Here, we evaluated ANXA1 protein expression in EOC clinical samples.

Method: Using immunohistochemistry (IHC), we retrospectively assessed ANXA1 expression in epithelial cells of 121 pre-chemotherapy EOC samples and 40 normal ovarian samples from patients treated at Salah Azaiez Institute. We compared ANXA1 expression in normal versus cancer samples and searched for correlations with clinicopathological features.

Results: Fifty one percent of tumour samples showed positive epithelial ANXA1 staining versus 26% of normal samples (p=1.16E-02, Fisher’s exact test). We showed that epithelial ANXA1 expression was associated with good response to chemotherapy (p=1.68E-02, Fisher’s exact test).

Conclusion: Epithelial ANXA1 overexpression in tumours could be an early diagnostic protein and contribute to the good response to chemotherapy in EOC cases, suggesting a potential therapeutic interest of ANXA1 activation for targeting tumour epithelial cells.

PS-04-026

Stromal expression of MARCKS protein and resistance to chemotherapy in ovarian carcinomas

M. Manai^*, R. Doghri, L. Charfi, P. Finetti, K. Mrad, M. Driss, F. Bertucci

^*Paoli Calmettes Institute, Oncologie Moléculaire, Marseille, France

Background & Objective: Epithelial Ovarian Cancer (EOC) is the most lethal gynaecological cancer. Identification of new therapeutic targets is crucial. MARCKS protein expression found to be implicated in cancer aggressiveness.

Method: We measured MARCKS protein expression in normal ovarian and EOC samples and searched for correlations with clinicopathological features. MARCKS status was evaluated by immunohistochemistry in 118 tumour samples and 40 normal ovarian samples. Expression was assessed on the epithelial and stromal cells. We compared MARCKS expression in normal versus cancer samples and with histopathological features.

Results: In tumour samples, the staining was observed mainly in stromal cells notably fibroblasts and to a lesser degree in tumour epithelial cells (p=2.37E-05). A correlation was found between stromal MARCKS expression and resistance to chemotherapy (p=3.9E-0.02). There was no correlation between stromal IHC MARCKS statutes and the other clinicopathological features

Conclusion: Stromal MARCKS overexpression in tumours might contribute to cancer-associated fibroblasts activation and explain the poor prognosis of EOC. Targeting stromal activation by inhibition of MARCKS might represent an approach targeting the cooperative tumour stroma of EOC.

PS-04-027

Leiomyoma with bizarre nuclei. A study of 108 cases focusing on clinicopathological features, morphology and fumarate hydratase alterations

M. Gregova^*, K. Nemejcova, M. Bartu, M. Mara, B. Boudova, I. Ticha, J. Hojny, J. Laco, L. Krbal, P. Dundr

^*Charles University, Dept. of Pathology, Prague, Czech Republic

Background & Objective: Leiomyoma with bizarre nuclei (LBN) is a rare variant of uterine smooth muscle neoplasm. Recent studies suggest fumarate hydratase (FH)’s involvement in these tumour’s pathogenesis. We analysed 108 cases focusing on clinical features, morphology, immunohistochemical and mutation analyses of FH and compare them with another 92 smooth muscle tumours – 50 usual leiomyomas (UL) and 42 leiomyosarcomas (LMS).

Method: Tissue microarrays were prepared and immunohistochemical analysis of FH was performed. Coding regions of FH were Sanger sequenced in 120 cases (53 LBN, 47 UL and 20 LMS).

Results: Follow-up data was available in 92 patients, and 19% patients showed local clinical recurrence after myomectomy. Two other patients presented with LMS – one in a vaginal stump and second in uterus. These tumours arose independently of LBN. FH expression was lost in 61% of LBN, 2% of UL, and 0% of LMS. Most LBN cases without FH expression show histologically prominent eosinophilic nucleoli, rhabdoid-like cells, and staghorn vessels. Pathogenic or probably pathogenic mutations were more frequent in LBN (51%) and LMS (45%), compared to UL (15%).

Conclusion: LBN is a rare neoplasia with a benign behavior. Aberrant FH expression is common in LBN, but rare or absent in UL and LMS. Negative expression of FH may represent an efficient screening method for FH aberration associated disorders.

This work was supported by Ministry of Health, Czech Republic (Conceptual development of research organization 64165, General University Hospital in Prague).

PS-04-028

Genital type rhabdomyoma; a rare case

D. Nergiz^*, M. Sedele, D. Süren, H. Yildirim, Z. Akgündüz, I. Atalay, O. Erol, A. Alikanoglu, C. Sezer

^*Antalya Research Hospital, Pathology, Turkey

Background & Objective: Genital type rhabdomyoma of cervix is an extremely rare tumour which presents as a cervical polypoid masses. It is essential to differentiate it from benign and malignant mimickers.

Method: A 47-year-old patient presented with menorrhagia and pelvic pain to gynaecology clinic. During pelvic exam; a cervical polyp was detected. Polypectomy specimen was received in formalin. Specimen diameter measured 4 cm and showed a white lobulated surface. Immunohistochemical stains were conducted in order to identify the tumour.

Results: On microscopic examination the polyp was covered by non-keratinizing squamous epithelium. There was well-vascularized tissue, composed of fusiform or stellate cells, arranged in a myxoid stroma. The stroma showed numerous spindle cells with abundant eosinophilic cytoplasm, vesicular nuclei placed peripherally or centrally and conspicuous nucleoli. The cytoplasm of these cells was cross-striations were readily visualized. Nuclear atypia is absent and mitotic figures were not seen. Immunohistochemical studies showed positive cytoplasmic staining for desmin and myogenin in the cells with rhabdomyoblastic differentiation. Staining for cytokeratin and S100 was negative in these cells. The diagnosis of genital type rhabdomyoma was made.

Conclusion: Genital type rhabdomyoma is a rare benign mesenchymal tumour with distinctive clinical, pathological and behavioral features. The genetic alterations of genital type rhabdomyoma are unknown. The prognosis of rhabdomyoma of uterine cervix is excellent with surgical intervention and complete removal. We reported this case because of the rarity of these tumours in extracardiac localization and to point to differential diagnosis.

PS-04-029

Utility of P16 expression on differential diagnosis of cervical intraepithelial neoplasms; how applicable for the novice in pathology

E. Üstündas^*, F. Eren, D. Çelikoglu, H. E. Ozay, Y. Gümüstas, Y. Dede

^*Marmara University, Faculty of Medicine Pathology, Istanbul, Turkey

Background & Objective: P16 immunhistochemistry is used to fascilitate the diagnosis of cervical intraepithelial neoplasia. Our aim is to investigate p16 expression patterns in differential diagnosis of cervical precursor lesions and to see its applicability for the inexperienced in pathology.

Method: Representative sections from the colposcopic biopsies of 45 patients with diagnosis of chronic cervicitis (n = 12), CIN1 (n = 12) CIN2 (n = 14) and CIN 3 (n= 7) were selected and immunohistochemically stained with p16. P16 staining pattern was classified as negative(0); patchy (1); block positive less than 1/3(2), less than 2/3 (3) and more than 2/3 (4). The results were evaluated independently by medical students without pathology experience and a gynaecologic pathologist.

Results: All chronic cervicitis cases showed less than 1/3 of basal staining, whereas 85.7% of CIN3 cases showed more than 1/3 (p=0.02). Negative or patchy staining pattern was observed more frequently in chronic cervicitis than CIN1 (p = 0.014). Although CIN1 and CIN2 cases were not differentiated by p16 expression, there was significant difference between CIN 1 and CIN2/3 combined (p=0.001) 92% compatibility was determined among the evaluators.

Conclusion: P16 expression is increasing gradually from CIN1 towards CIN3. It is seen that p16 expression is useful in nonneoplastic/neoplastic discrimination and CIN1/CIN2-3 discrimination. This method can be easily applied even by persons who have no experience in pathology and can prevent the difficulties in making histopathological diagnosis.

PS-04-030

Chemotherapy response score after neoadjuvant chemotherapy in ovarian advanced high-grade serous carcinoma correlates with peritoneal cancer index

I. Torralba^*, M. A. Martínez, H. Rodrigo, A. M. Quintero, J. R. Velásquez, G. Matheu

^*Hospital Son Espases, Anatomía Patológica, Palma de Mallorca, Spain

Background & Objective: Ovarian high-grade serous carcinoma (HGSC) is frequently associated with peritoneal carcinomatosis. Patients with advanced stage HGSC can be treated with neoadjuvant chemotherapy (NACT) prior to debulking surgery (DS). The chemotherapy response score (CRS), developed and validated by Böhm et al, is a three-tier histopathologic scoring system for measuring response to NACT in interval DS specimens of HGSC. We aim to determinate if CA-125 levels and peritoneal cancer index (PCI) after NACT correlate with CRS in our series.

Method: 22 cases of HGSC treated with NACT and interval DS at our institution from 2014 to 2018 were included. In each case, one omental slide showing the maximum tumour was selected. Two pathologists scored each slide according to CRS. Ca-125 levels and PCI after NACT were collected from medical records. CRS was correlated with PCI and the decrease in Ca-125 levels. Statistics were performed using Mann-Whitney and Wilcoxon tests.

Results: All patients showed a reduction in Ca-125 levels (ranging from 32.04% to 98.37%). IPC after NACT ranged from 1 to 28. CRS was as follows: CRS1: 6 cases, CRS2: 9 cases, and CRS3: 7 cases. PCI showed an overall significant correlation with CRS (p =.004) and differences when comparing CRS1 vs CRS3 (p=.002) and CRS2 vs CRS3 (p=.003). There was no significant difference in CRS1 vs CRS2 (p=.328).

Conclusion: PCI and CRS showed good correlation in our series. Although no significant correlation was found between CRS and CA-125, a larger sample may minimize power issues. Additional cases and outcome data will be evaluated to determine the clinical significance of CRS.

PS-04-031

Primary lymphoma of the female genital tract. Three new cases

I. Fernández^*, B. Aguiar Losada, C. Arean Cuns, Y. P. Rodriguez Velandia, R. Guarch Troyas, M. Montes Díaz, F. García Bragado

^*Navarra Hospitalary Complex, Pathology, Pamplona, Spain

Background & Objective: Primary lymphoma of the female genital tract (PLFGT) is an uncommon entity. The most common location is the ovary and the most common type of is diffuse large B-cell lymphoma (DCBCL). Aim is to analyse all cases of PLFGT in our hospital and to compare the clinical and pathological features to those described in the literature.

Method: Cases were collected retrospectively from the last 18 years; revision of clinical and the anatomopathological features were performed.

Results: Three cases with diagnosis of PLFGT were found, with a mean age of 53 (range 29-81). The most common clinical feature was vaginal bleeding (2/3). The most frequent location was cervix (2/3), with the highest Ann Arbor stage and positivity for tumour markers. 2/3 cases had completed remission. All cases had final diagnosis of DCBCL, and 2/3 cases were germinal centre subgroup. One case of these two ones was positive for C-MYC, BCL-2 and BCL-6 by immunohistochemistry (IH) and only BCL-2 was translocated by FISH. The case activated B-cell-type expressed C-MYC and BCL-6 by IH but FISH was not valorable.

Conclusion: LPTGF is an uncommon entity, which most common location is the ovary. In our revision the most common location was cervix. The mean age, the histology type and the most frequent clinical features are according to literature. Tumour markers are high in the most advanced cases as described in the literature. All cases were treated according to the protocol and had a favourable evolution, which is characteristic of LPTGF, opposite from what occur with secondary lymphoma.

PS-04-032

Renal cell carcinoma with bilateral ovarian metastasis

N. Koufopoulos^*, E. Pigadioti, E. Tsouma, K. Kosmas, L. Khaldi

^*Saint Savvas Cancer Hospital, Pathology, Athens, Greece

Background & Objective: We report a case of Renal Cell Carcinoma (RCC) with bilateral metastases to the ovaries. Ovarian metastasis of RCC is rare with a number of 38 cases in the English literature

Method: A 45-year-old patient with a history of RCC was admitted to the hospital due to symptoms of ascites (abdominal pain, increased abdominal girth and dyspnea). Ultrasound examination revealed a 9.4 cm solid-cystic mass on the left adnexal region. Metastatic disease in the greater omentum, paraortic and retroperitoneal lymph nodes was found on further imaging studies. Tumour markers were normal. A second primary neoplasm was suspected. Therefore an hysterectomy and bilateral salpingo-oophorectomy, omentectomy and appendicectomy were performed.

Results: On gross examination the tumour of the left ovary measured 9.8 cm and was predominantly cystic. On microscopic examination both ovaries, the greater omentum the right fallopian tube and the peri-appendiceal fat were infiltrated. The tumour consisted of nests and glandular structures with areas of papillary formation. The cells had moderately atypical nuclei without significant pleomorphism and abundant clear cytoplasm. Few mitotic figures were found. Areas of necrosis were also observed. A prominent thin walled vascular network was present. Immunohistochemical study was positive for RCCma, CD-10 and Vimentin and negative for CK-7 and WT-1 confirming histological findings.

Conclusion: The diagnosis of malignant neoplasm with morphological and immunohistochemical features consistent with metastatic RCC was made.

PS-04-033

Atypical polypoid adenomyoma: Clinicopathological characteristics of 7 cases

D. Nergiz^*, H. Yildirim, D. Süren, Z. Akgündüz, I. Atalay, O. Erol, A. Alikanoglu, C. Sezer

^*Antalya Research Hospital, Pathology, Turkey

Background & Objective: Atypical polypoid adenomyoma (APA) is a rare benign mixed epithelial and mesenchymal tumours of uterus. We investigate the clinicopathological characteristics of 7 cases of atypical polypoid adenomyoma.

Method: This is a retrospective analysis performed in the Department of Pathology of University Of Health Sciences Antalya Training and Research Hospital, Antalya, Turkey over a period of 6 years (March 2012- March 2018) which involved a total of 7 cases with APA.

Results: A total of 7 patients were diagnosed with APA. Revised and re-confirmed 7 cases of the diagnosis. On microscopic examination, architecturally and cytologically atypical endometrial glands separated by intersecting fascicles of smooth muscle cells were seen in all cases. One case included focal atypical endometrial hyperplasia within it. The median age was 49,4 years (range: 37 – 66 years). 4 patients were premenopausal, 3 patients were postmenopausal. The most common symptom was abnormal uterine bleeding (4 patients). Lesions were obtained by using dilatation and curettage in 5 cases and myomectomy in 2 cases. The median level of CA125 was 21,5 U/ml (range: 6,4 – 69,6 U/ml) and it was within a normal range.

Conclusion: The most important entity in the differential diagnosis is atypical hyperplasia or endometrioid adenocarcinoma. APA have high risks of residual lesions and recurrence. Close follow-up with hysteroscopy and biopsy examinations are important for those patients with conservative treatment.

PS-04-034

Primary primitive neuroectodermal tumour of the cervix and ovary: a report of two cases

L. M. Nova Camacho^*, R. Guarch, C. Arean, M. Cevallos, I. Fernandez de los Reyes, Y. Rodriguez, T. Zudaire, B. Aguiar, D. Requena, F. Nogales

^*Complejo Hospitalario Navarra, Anatomía Patológica, Pamplona, Spain

Background & Objective: Primary primitive neuroectodermal tumour (PNET) of the cervix and ovary is a very rare entity, with 21 and 100 cases described respectively. PNET has been grouped into two major categories: Peripheral (with EWSR1 rearrangement) and central. We describe the clinicopathological features of two new cases.

Method: First case: 25-year old woman with uterine bleeding and lower abdominal pain for three months. CT revealed a 10 cm mass in the cervix. Hysterectomy, double adnexectomy and bilateral pelvic lymphadenectomy were performed. Second case: 48-year old woman with alterations of menstrual cycle and abdominal distension for two months. CT revealed a 10 cm mass in left ovary. Ovarian surgical protocol was performed.

Results: Microscopically both cases showed a malignant neoplasm composed of round cells of intermediate size, immunoreactive for FLI1, CD99, vimentin and CD117. Cytokeratin, Inhibin, CD10, LCA, HMB-45 were negative. SALL4, SOX2, synaptophysin were negative in the first case and positive in the second. Molecular study by FISH showed breakdown of the EWS gene (22q12) only in the first case. Primary PNET was diagnosed in both cases. Both patients were treated with chemotherapy, the first case is free of disease 4 years after diagnosis, the second case had progression of the disease and died 8 months after diagnosis.

Conclusion: PNET arising from cervix and ovary is very rare and represents a real diagnostic challenge. Immunohistochemistry and molecular study are fundamental for an accurate diagnosis and for discarding other tumours. The distinction of central and peripheral PNET may have prognostic and therapeutic implications.

PS-04-035

Primary clear cell carcinoma of the cervix: report of 10 cases and review of the literature

M. Driss^*, M. Manai, N. Boujelbene, G. Sahraoui, R. Doghri, I. Abbes, K. Mrad, l. Charfi

^*Institut Salah Azaiez, Tunis, Tunisia

Background & Objective: To explore the clinical diagnostic and therapeutic characteristics, prognostic factors of patients with primary clear cell carcinoma of the cervix.

Method: The clinical, pathologic and follow-up data of patients with primary clear cell carcinoma of the cervix treated in our institute from Jan 2003 to Dec 2014 were collected and analyzed retrospectively. The relative literature was reviewed.

Results: The average age was 54.6 with extremes ranging from 36 to 76 years. No patients were exposed to diethylstilbestrol (DES) and none had a screening smear. The primary symptom was mostly irregularly vaginal bleeding. 2 cases were of stage I b, 4 of stage IIa, 3 of stage IIb and 1 of stage IIIa. All cases were negatif for p16 (INK4a) in histology. All of patients underwent neoadjuvant radiotherapy with or without chemotherapy followed by total hysterectomy with bilateral salphingoophorectomy and pelvic lymph node dissection. There was no relapse or metastasis after 4 years of follow-up in 5 cases. One patient was lost to follow-up just after the intervention and four had recurrence or metatases.

Conclusion: Clear cell carcinoma is a rare entity that does not seem to be related to HPV. Its clinical and pathological features and prognosis differ from those of conventional adenocarcinoma.

PS-04-036

PD-L1 expression in cancer tissues vs. soluble sPD-L1 in the plasma of patients with ovarian epithelial carcinoma

A. Giatromanolaki^*, E. Kontomanolis, M. Sotiropoulou, A. Mitrakas, S. Pouliliou, M. Koukourakis

^*Democritus University of Thrac, Dept. of Pathology, Alexandroupolis, Greece

Background & Objective: The immune checkpoint PD-1/PD-L1 pathway has been recently revealed as a major target for therapeutic interventions. Indeed, PD-1/PDL1 blocking agents have been approved for the treatment of melanoma and advanced/metastatic lung, head-neck, and urothelial cancer.

Method: In the current study, we examined in parallel the expression of PD-L1 in neoplastic tissue and the plasma (soluble sPD-L1) of seventeen (17) patients with epithelial ovarian carcinoma.

Results: Soluble sPD-L1 levels were significantly higher in the plasma of patients with ovarian cancer compared to healthy women (median/range 103/29-178 vs. 63/47-98 pg/ml; p=0.01). Immunohistochemical analysis of cancer tissues from these patients showed a mixed cytoplasmic and membrane expression of PD-L1 in a varying percentage of cancer cells: 6/17 (35.3%) were negative, 4/17 (23.5%) showed reactivity in 20-50% and 7/17 (41.2%) in 60-90% of cancer cells. PD-L1 was also expressed in the tumour-associated lymphocytes and macrophages in 10/17 (58.8%) cases. Stroma PD-L1 expression was not related to cancer cell expression. There was no statistical difference in the concentration of sPD-L1 between the groups of patients with negative, low or high cancer cell PD-L1 expression.

Conclusion: Aside from cancer cells, immune infiltrating cells may be involved in the immune suppression characterizing a subset of ovarian cancer patients. The presence of high PD-L1 amounts in the plasma of patients may also neutralize anti-PD-L1 antibody therapies. The optimal biomarkers for the administration of therapeutic anti-PD-L1/PD1 antibodies remains a subject for investigation.

PS-04-037

Incidental gonadal germ cell tumours at the time of prophylactic gonadectomy in patients with Swyer syndrome - a report of 3 cases

N. Basheska^*, B. Ognenoska-Jankovska, S. Veljanoska, D. Plaseska-Karanfilska

^*UCRO, Dpt. of Histopathology & Cytology, Skopje, Republic of Macedonia

Background & Objective: Swyer syndrome (46,XY pure gonadal dysgenesis) is an uncommonly encountered condition in which gonadectomy is recommended upon diagnosis due to a significant risk of malignant transformation of the dysgenetic gonads. The aim of this study was to present our experience with incidentally found germ cell tumours in patients with Swyer syndrome.

Method: We report the clinico-pathological characteristics of 3 cases of female phenotypic patients presenting with primary amenorrhea who underwent prophylactic bilateral laparoscopic gonadectomy with salpingectomy following a diagnosis of Swyer syndrome. At the time of diagnosis, they were 17 to 20 years old. The presenting features were hypogonadotropic hypogonadism and 46, XY karyotype. A hypoplastic uterus with normal looking fallopian tubes and bilateral gonads were detected by ultrasonography and confirmed during laparoscopy. The patients with dysgerminoma underwent postoperative chemotherapy. All three patients are alive and well 70, 115 and 144 months following surgery.

Results: The histopathological examination of the streak gonads which were completely sampled and embedded revealed the presence of bilateral predominantly “burnt out” gonadoblastoma in all patients. In addition, in two patients, a coexisting dysgerminoma of 1.5 and 3.8 cm in diameter FIGO stage IC1 in the right gonad was confirmed. The sequencing of the SRY gene of the patient with bilateral gonadoblastoma without dysgerminoma overgrowth revealed a C/G substitution at the first nucleotide of codon 133, leading to Arg/Gly replacement in the SRY protein.

Conclusion: Our data suggest that patients with gonadal dysgenesis and 46, XY karyotype should be referred for bilateral gonadectomy and their operative specimens should undergo meticulous histopathological examination because of the high risk of neoplastic transformation.

PS-04-038

A clinicopathologic study of early stage placental mesenchymal dysplasia

M. Fukunaga ^*

^*Shinyurigaoka General Hospital, Pathology, Kawasaki, Japan

Background & Objective: To elucidate clinicopathologic features of early stage placental mesenchymal dysplasia (PMD).

Method: Ten cases of PMD with gestational age less than 20 weeks were clinicopathologically analyzed with an immunohistochemical study of p57 (Kip2) (p57).

Results: Maternal ages ranged from 23 to 40 years. Five patients were initially diagnosed as partial partial mole (PM) and one was as complete mole (CM) with twin on ultrasound examination. The gestational periods ranged from 12 to 19 weeks. One case was associated with Beckwith-Wiedemann syndrome. Histologically, early stage PMD was characterized by moderate swelling of stem villi with cistern formation, myxoid change, dilated veins, mild stromal cell proliferations, and the absence of trophoblastic hyperplasia. Dilated subchorionic vascular vessels with or without luminal thrombosis, or chorangiosis, which were observed in the third trimester PMD, were not found. Regarding p57, villous stromal cells were diffusely positive in 3 cases, focally positive in 5, and uniformly negative in 2.

Conclusion: Early stage PMD can be clinically or pathologically misdiagnosed as abortion, PM, or CM with a twin. Histologic features in early stage PMD are less distinctive compared with those of PMD in the third trimester. The diagnostic clues are moderate swelling of stem villi with cistern formation, myxoid change, dilated veins, and mild stromal cell proliferations and the absence of trophoblastic hyperplasia. The p57 immunohistochemical study may be useful for differential diagnoses in equivocal cases. It is important to identify PMD cases in early stage to choose appropriate treatments.

PS-04-039

E-cadherin expression in high grade serous ovarian carcinoma – clinicopathological study

S. Kostadinova-Kunovska^*, G. Petrushevska, R. Jovanovic, V. Janevska, I. Aluloski, M. Tanturovski, S. Veljanovska

^*Institute of Pathology, Faculty of Medicine, UKIM, Skopje, Republic of Macedonia

Background & Objective: E-cadherin is epithelial cell adhesion molecule, which has been downregulated in various malignant epithelial neoplasms. We aimed to evaluate its expression in high grade ovarian serous carcinomas (HGOSC) of advanced stage.

Method: We analysed immunohistochemical expression of E-cadherin and compared it to multiple clinicopathological data and overall survival in 76 cases of HGOSC in advanced stage (FIGO III-IV). Presence of signal, its distribution (membranous and/or cytoplasmic), percentage of positive tumour cells and intensity of staining (mild, moderate and strong) were evaluated.

Results: The mean age of the patients was 58,74 years (24-78), with the majority (56,6%) in stage IIIC, 28,9% in stage IIIB, 10,5% in stage IIIA and 3,9% in stage IV. The mean post-operative survival period was 35,36 months (1-90 months). Immunohistochemical analyses showed membranous and/or cytoplasmic localisation of E-cadherin in all cases. In 68 cases (89,5%) more than 10% of the tumour cells were positive, and in the reminding 8 cases (10,5%) the positivity was present in less than 10% of the tumour cells. We observed heterogeneous intensity of the signal, with dominant strong signal in most of the cases (68.4%), moderate in 25% cases and mild signal intensity in 6,6% of the cases. The statistical analysis showed that both low intensity of signal and expression in less than 10% of the tumour cells were associated with shorter overall survival in patients (Kaplan-Meier, p<0.001).

Conclusion: The study shows that the decreased E-cadherin expression in tumour cells of HGOSC is associated to adverse prognosis, making it a potential prognostic marker.

PS-04-040

Pure primary squamous cell carcinoma of the ovary

N. Koufopoulos^*, E. Pigadioti, D. Nasi, E. Tsouma, K. Kosmas, L. Khaldi

^*Saint Savvas Cancer Hospital, Pathology, Athens, Greece

Background & Objective: We present a case of pure primary Squamous Cell Carcinoma of the Ovary (SCCO). Pure primary SCCO is a very rare tumour with less than 40 reports in the English literature.

Method: A 54-year-old female patient with history of conization of the cervix 23 years ago because of cervical intraepithelial neoplasia III, was admitted to the gynaecology department due to gradually worsening abdominal pain lasting for four months. Imaging studies revealed a cystic lesion with solid components, originating from the right adnexa with measuring 8,6 x 7,6 cm. Patient had a total hysterectomy, bilateral adnexectomy and omentectomy. Grossly, the tumour was mainly cystic and partly solid. On microscopic examination the ovary was extensively infiltrated by a malignant tumour that was composed of polygonal squamoid cells devoid of keratin pearls or individual cell keratinization. Nuclear pleomorphism and few intercellular bridges were observed. Mitotic figures were numerous. Extensive necrosis was also present. Evidence of any other associated lesions such as dermoid cyst, Brenner tumour, or endometriosis was not found. Immunohistochemical study was positive for CK7, CK5 and P63, negative for CK20, TTF-1, GATA-3 and P16. Ki-67 index stained 40% of tumour nuclei.

Results: The neoplasm was diagnosed as morphologically and immunohistochemically consistent with pure primary SSCO. The patient received adjuvant chemotherapy and died 9 months after surgery.

Conclusion: SCCO is a rare tumour with poor response to chemotherapy. Disease outcome is poor. Tumour stage and grade is correlated best with overall survival.

PS-04-041

Myeloid sarcoma of the vagina: a case report

Y. Rogov^*, N. Kornev, O. Solodkaya, E. Grigorieva

^*Belarusian Medical Academy, Pathology, Minsk, Belarus

Background & Objective: Myeloid sarcoma (MS) is a rare solid extramedullary tumour consisting of immature myeloid cells and commonly associated with acute myelogenous leukemia (AML). Sometimes it appears as a neoplasia without prior evidence of leukemia. In the latter situation, patients usually develop AML within a few days to several months. MS may occur at almost any anatomic site. Involvement of the female genital tract is uncommon. We report a case of MS observed in a vagina.

Method: A 16-year-old female patient was hospitalized with complains of acute vaginal bleeding for some days. On colposcopic examination on the anterior wall of the vagina a cyanotic dense tumour-like lesion was found in the form of a cauliflower with a decay, filling the vagina, measuring 2.5 x 3.5 x 2.7 cm. Tissue samples were investigated histologically and immunohistochemically.

Results: Microscopic evaluation of the vaginal lesion revealed a diffuse dense cellular infiltration of stroma by moderately sized immature cells with scanty cytoplasm. Some of them had blastic morphology and visible nucleoli. Many cells were myeloid or atypical mononuclear with round to oval or irregularly shaped, angulated nuclei, irregular nuclear contours, fine chromatin. There were a lot of small capillaries and larger dilated vessels, areas of necrosis with ulceration. Immunohistochemical staining was positive for CD45, MPO, lysozyme, CD117, CD68. Ki67 reached about 50%. MS was diagnosed and careful examination of the patient identified AML.

Conclusion: The histologic diagnosis of MS is difficult especially in unusual location without AML clinical manifestations. Histological signs of myeloid differentiation in tumour and immunohistochemistry help make the correct diagnosis.

PS-04-043

Mixed carcinoma (adenoid basal carcinoma and microinvasive squamous cell carcinoma) of cervix: a case report

S. Yildirim^*, H. Tosun Yildirim, C. Sadullahoglu, I. Ureyen, D. Suren

^*Antalya Education and Training, Pathology, Turkey

Background & Objective: Adenoid basal carcinoma (ABC) is often associated with squamous intraepithelial lesion or another carcinoma subtype. The presence of any invasive carcinoma subtype with ABC should be reported as a mixed carcinoma.

Method: A 77-year old multiparous woman was referred to hospital for abnormal bleeding. Total abdominal hysterectomy and bilateral salphingooferectomy was performed. On macroscopic examination, there was no marked mass in the cervix.

Results: On microscopic examination, lobular clusters of basaloid nests and a few glands were separated by unaltered endocervical stroma. Additionally, cervical intraepithelial neoplasia 3 were found along side of the superficial and glandular epitelium. At the same time, dysplastic epithelium of the cervical gland showed microinvasion through the cervical stroma which was not greater than 3 mm.

Conclusion: The differential diagnosis of ABC includes adenoid basal hyperplasia, adenoid cystic carcinoma, basaloid squamous cell carcinoma and neuroendocrine carcinomas. In this case report, we reviewed an uncommon tumour and discussed differential diagnosis.

Sunday, 9 September 2018, 09:30 - 10:30, Exhibition Hall I/II

PS-05 | Nephropathology

PS-05-001

A retrospective clinical and pathological study of 11 patients with kidney granulomatous vasculitis without glomerular involvement

V. Gnemmi^*, N. Tabibzadeh, J.-B. Gibier, J. Vérine, M.-F. Hennino, G. Burda, J.-P. Hammelin, A. Boldron, J.-J. Boffa, L.-H. Noel, I. Brocheriou, D. Buob, M.-C. Copin, P. Vanhille

^*Lille University Hospital, Pathology, France

Background & Objective: Renal failure resulting from granulomatous vasculitis without glomerulonephritis was rarely reported. The aim of this study was to describe the characteristics of patients with kidney biopsy showing such features.

Method: We retrospectively analyzed the clinical, biological and histological data of patients from 4 French nephrology centers, between 1984 and 2016.

Results: Eleven patients (5 male, mean age 55.4 years, range 30-73) were included. Clinical presentation was a flu-like syndrome with hyperthermia (n=11), myalgia/arthralgia (n=7). All patients displayed acute renal failure (mean serum creatinine: 4.4 mg/dL, range 1.3-9.5, mild proteinuria (0.8 ±0.2 g/d) and inflammatory syndrome (median CRP 104, range 19-209). Microscpic hematuria was inconstant (n=7). All kidney biopsies showed granulomatous inflammation of the walls of interlobular arteries. The final diagnoses were sarcoidosis (n=2), microscopic polyangiitis (n=2), granulomatosis with polyangiitis (GPA) (n=1), polyarteritis nodosa (PAN) (n=1). For 2 patients, drug-induced vasculitis was evoked and could be related to antibiotic and non-steroidal anti-inflammatory drugs. For 3 patients, final diagnosis could not be definitively established, and drug-induced, infectious, PAN or cryoglobulinemia were presumed etiologies. Follow-up was marked by one death (1 PAN patient due to cerebral hemorrhage), 2 chronic renal replacements (1 GPA and 1 sarcoidosis) and kidney function improvement for the remaining patients (median eGFR 64 ml/min/1.71m2, range 11-104). Drug-associated vasculitis suspected patients were younger with better renal outcome (eGFR 74 and 104 ml/min/1.73m2).

Conclusion: A final diagnosis could be challenging to reach for this rare renal vasculitis. Drug-induced vasculitis group seemed to harbour the favourable prognosis.

PS-05-002

Membranoproliferative glomerulonephritis due to visceral leishmaniasis in an immunocompromised patient: a case report and literature review

J. Martín López^*, G. G. Yange Zambrano, M. L. Cagigal Cobo

^*Hospital Marqués de Valdecilla, Pathology, Santander, Spain

Background & Objective: Membranoproliferative glomerulonephritis (MPGN) is a pattern of injury characterized by mesangial and endocapillary proliferation, double contours along the capillary walls, and lobular accentuation of the capillary tufts. Infections are an important cause of MPGN that are usually associated with an immune complex–mediated MPGN.

Method: To report a case of MPGN with Leishmaniasis in a patient HIV infected, we describe the clinicopathological details and review the literature.

Results: A 50 year-old male patient with history of HIV infection was admitted to our hospital due to a nephrotic syndrome. Physical examination showed gross edema of legs and reddish, papular skin lesions on the chest and abdomen The laboratory analyses revealed a low viremia and CD4 count of 519 cells/mm3. Peripheral blood counts showed anemia and thrombopenia. A renal biopsy was performed to determine the cause of proteinuria and on light microscopy we observed a MPGN pattern in the glomeruli with interstitial inflammatory infiltrate mostly of lymphocytes. Into the capillary lumen of the glomeruli there was numerous Leishmania amastigotes. There were 2 glomeruli present for immunofluorescence microscopy and showed bright staining for IgM, IgG, C1q and C3 and lower for C4. After the diagnosis also the bone marrow was involved and the patient started with liposomal amphotericin B as suppressive therapy.

Conclusion: Diagnosis of Visceral Leishmaniasis (VL) in HIV infected patients can be difficult due to atypical presentations like that in our case. The VL relapses and depend on the immunologic status of the patient.

PS-05-003

The histopathological spectrum of monoclonal gammopathies of renal significance: a single centre experience

C. Roufosse^*, T. Brah, E. Troy-Barnes, N. Duncan, K. Naresh, A. Chaidos, R. Charif, H. T. Cook, A. Kousios

^*Imperial College, Division Immunology, London, United Kingdom

Background & Objective: Monoclonal Gammopathy of Renal Significance (MGRS) encompasses renal histopathological entities caused by Monoclonal Immunoglobulins (MIg) in patients who do not meet criteria of symptomatic lymphoma or myeloma (MM). We describe the spectrum of MGRS histopathological diagnoses in our centre.

Method: Native renal biopsies (2006-2017) that met the following criteria were included: evidence of MIg or light chain in glomeruli, tubules, vessels and/or interstitium. C3GN and TMA cases associated with MIg were excluded.

Results: MIg-associated lesions were identified in 163/4,374 native biopsies (3.7%). After exclusion of symptomatic MM and lymphomas, 68 biopsies (1.5%) were consistent with MGRS. Median age at diagnosis was 65 years (range 25-87). Renal histological diagnoses included: amyloidosis (n=28, 41%), Proliferative GN with MIg Deposits (PGNMID) (n=13, 19%), MIg Deposition Disease (MIDD) (n=12, 18%), Light Chain Tubulopathy (n=5, 7%), Type-1 Cryoglobulinaemic GN (n=6, 9%), Intracapillary Monoclonocal IgM without Cryoglobulin (n=2, 3%), Crystal Cryoglobulinaemia (n=1, 1.5%) and Fibrillary Light Chain restricted GN (n=1, 1.5%). Serum Free Light Chain assay was performed in 42 patients and had an abnormal ratio in 24. Haematological diagnosis was possible in bone marrow histology (BMAT) in 53 patients. These included MGUS (n=30, 56.6%), smouldering myeloma (n=17, 32%), lymphoplasmacytic lymphoma/Waldenstrom’s macroglobulinaemia (n=2, 3.7%), chronic lymphocytic leukaemia (n=3, 5.6%) and marginal zone lymphoma (n=1, 1.8%). 8/13 PGNMID and 3/12 MIDD cases did not have a detectable clonal B cell or plasma cell clone in BMAT.

Conclusion: MGRS are increasingly recognised since the term was introduced in 2012. Renal histopathology must be interpreted in conjunction with haematological diagnosis to guide treatment.

PS-05-004

Serum uromodulin correlates with kidney function in patients with membranous nephropathy and nephrotic syndrome

N. Kojc^*, Z. Pipan Tkalec, A. Ales Rigler

^*Faculty of Medicine, UL, Institute of Pathology, Ljubljana, Slovenia

Background & Objective: Recent studies have shown that serum uromodulin may serve as a biomarker of kidney function, allowing the identification of early stages of chronic kidney disease (CKD). A reduced number of functioning tubules in CKD may correspond to reduced urinary and serum concentrations of uromodulin. We analyzed the serum uromodulin concentration in patients with membranous nephropathy (MN) and nephrotic syndrome and correlated its concentration with biomarkers of kidney function and parameters of CKD obtained from renal biopsies.

Method: Serum uromodulin, serum creatinine and estimated glomerular filtration rate (eGFR) were assessed in 67 patients with nephrotic syndrome and biopsy proven MN and compared with 30 healthy individuals with normal serum creatinine. Interstitial fibrosis and tubular atrophy (IFTA) were scored according to the Banff criteria for transplant kidney. Univariate correlations between serum uromodulin and creatinine, eGFR and IFTA were calculated using Pearson‘s correlation coefficient.

Results: The serum uromodulin concentration in healthy controls was significantly higher from patients with MN and eGFR MDRD >90 ml/min/1.73m2 (CKD stage I) and patients with MN with CKD stage II –V (p<0.00). Decreased uromodulin serum concentration significantly correlated with increased serum creatinine, advanced CKD stage, decreased eGFR and increased amount of IFTA in patients with MN and nephrotic syndrome.

Conclusion: Our study indicated that uromodulin may allow identification of early CKD stages in patients with MN and nephrotic syndrome. Uromodulin might therefore provide substantial information on tubular function in patients with MN-related nephrotic syndrome and retained eGFR.

PS-05-005

Macrophage abundance predicts allograft long-term function and correlates with rejection and fibrosis in a cross-sectional study of transplanted kidneys

J. Schmitz^*, A. Khalifa, I. Scheffner, W. Dai, H. H. Kreipe, H. Haller, S. von Vietinghoff, W. Gwinner, J. H. Bräsen

^*Institute for Pathology, Nephropathology Unit, Hannover, Germany

Background & Objective: Standardized markers based on quantitative and qualitative evaluation and localization of immune cell density in kidney biopsies may improve diagnostic accuracy. Inflammation is difficult to quantify by eye at low densities. We measured macrophage abundances in renal allograft biopsies by digital image analysis.

Method: Kidney tissue of transplanted kidneys from surveillance (36%) and clinically indicated (64%) biopsies (n=350) was stained for macrophages using a monoclonal CD68 antibody (PGM1), scanned (Leica) and whole slide images were analyzed for immunopositively stained area using a digital pixel-based approach (Definiens Tissue Studio). Results were obtained separately for cortex, medulla and extrarenal tissue.

Results: Humoral and combined rejection were associated with increased macrophage infiltration (no rejection: cortex 2.6%; borderline: cortex 1.9%; cellular: cortex 2.5%; humoral rejection: cortex 4.4%; combined rejection: cortex 6.2%; p<0.05). The density of macrophages correlated with the time after transplantation: Highest mean values were measured when post-transplant time exceeded 1 year (cortex: 5.8% compared to <1year >90 days (4.1%), <90 days >8 days (1.3%), <8 days (1.5%); p<0.05). Evaluation of IF/TA showed an increase of infiltrating macrophages with fibrosis progression (ci0: 1.5%, ci1-3: 4.6%; p<0.001). In 6-week-surveillance-biopsies macrophage density was a significant predictor of an eGFR<30ml/min after four years (p<0.01).

Conclusion: The findings show that macrophages have essential roles in active rejection, chronic allograft injury and fibrosis and can be used as a prognostic marker in early renal transplant biopsies.

PS-05-008

Crosstalk between NCAM/FGFR and TGF-beta signalings: an in vitro study in cultured human proximal tubular epithelial cells

J. Markovic-Lipkovski^*, M. Zivotic, C. Müller, S. Radojevic-Skodric, G. Müller

^*Institute of Pathology, University of Belgrade, Serbia

Background & Objective: Epithelial-to-mesenchymal transition (EMT) contributes to repair and parenchymal damage during renal fibrosis. Neural cell adhesion molecule (NCAM) and fibroblast growth factor receptor 1 (FGFR1) are considered to be involved in the EMT process. We explored the role of NCAM/FGFR1 signaling and pro-fibrotic gene expression signatures as initiating/driving forces of EMT program in cultured human proximal tubular epithelial cells (hPTEs).

Method: In vitro EMT model of hPTEs in response to TGF-β1 (10ng/mL) exposure and NCAM/FGFR1 signaling responses were analyzed by light microscopy, immune-labeling, qRT-PCR and scratch assays. Modulation of FGFR1 was induced using PD173074 (100nM).

Results: Morphological EMT changes started 48h after TGF-ß1 treatment and was clearly apparent after 72 hours, associated with loss of CDH1 and transcriptional induction of SNAI1, SNAI2, TWIST1, MMP2, MMP9, CDH2, ITGA5, ITGB1, ACTA2 and S100A4. After 24 hours of TGF-β1 exposure at the early stage of EMT, transcriptional induction of several NCAM isoforms along with FGFR1 was observed, implicating a mechanistic link between NCAM/FGFR1 signaling and induction of EMT. These assumptions were further supported by the inhibition of the EMT program after specific blocking of FGFR1 signaling responses by PD173074.

Conclusion: Modulation of NCAM/FGFR1 signaling blocks the EMT program in cultured hPTEs. NCAM/FGFR1 signaling appears to be involved in initial phases of TGF-ß1 initiated EMT of tubular cells and thus could contribute to maladaptive repair and parenchymal damage during renal fibrosis.

PS-05-009

The comparison of the renal cortex and medulla for antibody mediated rejection

S. Sarioglu^*, S. Yildiz, H. Ellidokuz, M. Unlu

^*Dokuz Eylul University, Faculty of Medicine Pathology, Izmir, Turkey

Background & Objective: Peritubular capillaritis (PTc) and C4d expression are important criteria for antibody mediated rejection (AMR). This study aims to focus on cortical and medullary scores of PTc and C4d, and specificity and sensitivity of medulla for AMR diagnosis in the allograft biopsy.

Method: Cortex and medulla of 51 post-transplant biopsies were re-evaluated separately for PTc, C4d expression and acute tubular injury (ATI) according to the Banff 2014 scheme. These parameters and DSA status were compared separately in the medulla and cortex.

Results: There was a significant positive correlation between cortex and medulla for PTc (p= 0,036) and C4d (p= 0,001) scores. There was a significant association for ATI between the cortex (0.004) and medulla (0,076) for DSA positive cases. PTc was not detected either at the cortex or medulla in 26 (51%) cases (p=0, 00). PTc was observed in the cortex and medulla in 17 cases and 3 cases had PTc only in the cortex and 5 cases only in the medulla. The sensitivity, specificity, positive and negative predictive values of medullar PTc, predicting cortical PTc were 85,7%, 86,7%, 81,8%, and 89,7%, respectively.

Conclusion: Medulla is injured during AMR. Some renal biopsies have very limited renal cortex or just consist of medulla. If correlated with DSA, medulla findings can be a significant guide, when the cortex is restricted for diagnosis.

PS-05-011

C3 glomerulonephritis: a department's series

R. Veiga^*, R. Manso, A. Gaspar, N. Lopez, K. Soto, A. Serra

^*Hospital da Luz Lisboa, Anatomic Pathology, Queijas, Portugal

Background & Objective: C3 glomerulonephritis (C3GN) is caused by deregulation of the alternative complement pathway, with glomerular lesions and predominance of C3 deposits in immunofluorescence (IF). We aimed to determine the frequency and features of C3GN in our patients.

Method: A retrospective analysis was made of all renal biopsies of our deparment over the last 5 years. We selected those where the clinical data, laboratorial, pathological and genetic results were consistent with C3GN.

Results: From 227 cases, 6 were compatible with C3GN. Mean patient age was 46. Four patients had history of arterial hypertension, 1 of type 2 diabetes and 1 of chronic kidney disease. All presented with arterial hypertension, haematoproteinuria, acute kidney disease and low seric C3. Three had nephrotic proteinuria and four needed renal replacement therapy (RRT). Histologically, several patterns of GN were noted: 2 endocapillary (one with crescents and exsudative features), 2 membranoproliferative (1 with crescents), 1 necrotizing crescentic proliferative, and 1 global diffuse glomerulosclerosis. All had predominant C3 deposits on IF and electrodense deposits on EM. Genetic tests revealed homozyguous deletion of CFHR3/CFHR1 in one case. After immunosuppresion, 2 patients had complete remissions and one partial. The others remained on RTT.

Conclusion: C3GN was diagnosed in 2,6% of all RB studied. No uniform histologic features could be found. Patients should undergo genetic and immunologic studies.

PS-05-012

Immunohistochemical study of IgG4 and PLA2R in membranous nephropathy: can it be helpful to discriminate the primary forms of secondary ones? Preliminary results

A. Panizo^*, C. Arean, M. Gómez-Dorronsoro, L. Fernández, M. Abengozar, J. Manrique, F. García-Bragado

^*Complejo Hospitalario de Navarra, Spain

Background & Objective: Membranous nephropathy (MN) is more commonly a primary disease (pMN), but it also occurs as a secondary (sMN) to other conditions. The histopathological findings do not allow a differentiation between primary or secondary forms. Most patients with pMN have autoantibodies of IgG4 type against the M-type phospholipase A2 receptor (PLA2R). The aim was to evaluate an immunohistochemical panel with IgG4 and PLA2R in the differential diagnosis of MN.

Method: We studied the presence and distribution patterns of IgG4 and PLA2R in the glomeruli of 30 MN patients, using IHC. The clinical history of each patient was reviewed: MN were diagnosed as primary or secondary based on clinical data.

Results: 30 MN: 21 (70%) were primary, and 9 were sMN, based on clinical data. Only granular membranous deposits were considered as positive. Eleven cases presented granular membranous IgG4 deposits. In 4 cases deposits were diffuse and 7 were segmental and focal. Patients with diffuse deposits had more proteinuria. The 11 cases IgG4 (+), did not present clinically secondary causes of MN. PLA2R deposits were found in up to 100% of the pMN. All cases of Class V lupus MN (7 cases) showed absence of IgG4 and PLA2R deposits.

Conclusion: Preliminary results in our series, showed IgG4 membranous deposits in 36.7% and PLA2R in 70%. IHC of IgG4 showed a sensitivity of 52% and specificity of 100% to differentiate MN. However, IHC of PLA2R seems to be more sensitive and specific for pMN.

PS-05-013

Analysis of renal graft survival with pre-transplantation histological evaluation: the experience of a center

R. Almeida^*, A. C. Teixeira, L. Rodrigues, N. Afonso, F. Macário, C. Marinho, V. Sousa, R. Alves

^*CHUC, Pathology, Coimbra, Portugal

Background & Objective: The shortage of organs in renal transplantation forced the acceptance of marginal donors. Histological evaluation prior transplantation remains controversial. Analysis of marginal donors with pre-transplantation biopsy: histological score, receptor age, compatibility, time of cold ischemia and on dialysis.

Method: A retrospective and unicentric study was performed, including 127 patients who received marginal donor kidneys after biopsy (2009-2016). Histological evaluation was done using Remuzzi scale, and donors with score >/=4 were excluded. Level of significance set at 0.05.

Results: 204 donors performed the biopsy, with an exclusion rate of 62.3%. The mean score of the excluded donors was 4.8 ± 1.47. Donors had a mean age of 64.3±11.48years, and 54.33% were males. The mean cold ischemia time was 19.39±4.06hours. A total of 127 receptors were evaluated (79.53% male). The mean follow-up time was 4.2±2.3years. Mean receptors age was 57.68years, mean anti-HLA incompatibility was 4.04, and mean time on dialysis was 48.93months. It was found that 18.1% of patients had late function and 4.7% had nonfunctioning kidney. The histological score had no relation to graft function (p = 0.15). There was significance of GFR according to age (p=0.0011). The 1-year graft survival was 88.1%. The age of receptors and the time on dialysis had significance on graft survival (p=0.0498 and 0.0084).

Conclusion: The histological evaluation of marginal donors may have value in the exclusion of grafts with specific histological changes, but, in our cohort, histological score does not correlate with graft survival.

PS-05-015

Biopsy-proven acute tubulointerstitial nephritis in the elderly - a single centre study

M. Wagrowska-Danilewicz^*, M. Danilewicz

^*Medical University of Lodz, Nephropathology, Poland

Background & Objective: Acute tubulointerstitial nephritis (ATIN) begins abruptly, manifesting as acute kidney injury. Literature data suggest that the incidence of ATIN in the elderly has grown over the past decade. In view of the above, we decided to establish the prevalence of biopsy-proven ATIN in the elderly, and to compare laboratory and clinical as well as histological pattern of the renal injury in elderly patients and in adult patients with ATIN

Method: Patients who underwent a renal biopsy from 2006 to 2017 were reviewed, and 49 patients were identified with biopsy confirmed ATIN. We divided the population into two groups according to the age: Group I (n=22) adults (18-64 years) and Group II (n=27) the elderly (≤65 years).

Results: The total number of native biopsies was 1623, the overall prevalence of ATIN was 3.02%. Of the 1623 native renal biopsy specimens, 220 were performed in patients aged ≤65 years. During the 17 years of follow-up, there was a significant increase in the prevalence of ATIN in elderly individuals: from 6.45% in the first 4 years of observation (2006-2009) to 14.05% in the last 4 years (2014-2017). Laboratory findings and clinical manifestation were similar in both studied groups, however the elderly had lower eGFR as compared with younger patients. Histological pattern of renal injury was similar in both studied groups.

Conclusion: The study confirmed significant increase in biopsy-proven ATIN in the elderly in the last years. Clinical manifestation, laboratory and microscopic findings in renal biopsies were similar in younger and older groups in patients with ATIN.

PS-05-016

Anti-glomerular basement membrane glomerulonephritis in renal biopsies

Y. Rogov^*, M. Dmitrieva, T. Letkovskaya

^*Belarusian Medical Academy, Pathology, Minsk, Belarus

Background & Objective: Anti-glomerular basement membrane (anti-GBM) disease is a rare autoimmune disorder, one of the most severe form of crescentic glomerulonephritis (GN), leading to a rapid loss of kidney function. The aim of this study was to analyse anti-GBM GN clinical and morphological data in native kidney biopsies of adult patients.

Method: 694 kidney biopsies of the City Clinical Pathology Bureau (from 2011 to 2015) stained by haematoxylin and eosin, PAS, Masson trichrome, Congo red, Jones silver have been evaluated with light microscopy. Immunofluorescent staining for IgG, IgA, IgM, C3c, C1q, fibrinogen, k and λ light chains was performed on paraffin sections. These cases were confirmed by elevated serum anti-GBM antibody titers and linear IgG deposition along GBM in glomeruli.

Results: Among all kidney biopsies 5 cases (0.7%) were diagnosed with anti-GBM GN (2 males, 3 females). These cases accounted 3% of 165 with any extracapillary proliferation as well as 15.6% of 32 with extracapillary GN containing more than 50% of damaged glomeruli. In all the cases, the cellular and fibrocellular crescents were observed including 60% to 100% glomeruli, necrotic changes were revealed in three cases. The kidney biopsy was made one to three weeks after the onset of the disease. However, in these samples we already observed global glomerular sclerosis 10% to 75% and interstitial fibrosis 25% to 80%.

Conclusion: Anti-GBM GB is characterized by severe clinical manifestations and significant proliferative and necrotic changes in glomeruli. By the time of biopsy kidney tissue demonstrated high level of global glomerular sclerosis and high percent of interstitial fibrosis, indicating a rapid progression to irreversible changes.

Monday, 10 September 2018, 09:30 - 10:30, Exhibition Hall I/II

PS-06 | Cardiovascular Pathology

PS-06-001

Histopathological findings in ascending aorta wall with and without dilatation in patients with bicuspid valve

M. L. Aon Bertolino^*, D. Navia, M. Cervetti, M. Matoso, G. González, C. Morales

^*Federal Police Hospital, Pathology, Lujan, Argentina

Background & Objective: we study the thickness (E) of the ascending aortas (AAs) and the histopathological findings in biopsies from patients with and without dilatation with bicuspid valve.

Method: 184 patients with bicuspid valve. AAs diameter ≤ 40 mm was observed in 119 patients; AAs > 40 mm was seen in 65 patients. Biopsy of aorta was obtained, fixed in 10% formaldehyde, processed and stained with H & E, Masson's trichrome and Alcian blue. Histopathological findings were studied in semi quantitative grade (G): G 0 (without injury); G1 (0-10%); G2 (11-25%); G3 (26-50%); G4 (51-100%). E: 1,5 to 3 mm.

Results: AAs without dilatation: E: 1,51 - 2 mm: 46% of patients with G3 42% and G4 13% ; E: 2,01 – 2,5mm: 8% of patients with G3 22% and G4 33%; E: 2,51 – 3 mm: 16% of patients with G3 32% and G4 42%. AAs with dilatation: E: 1,51 - 2 mm: 20% of patients with G3 15% and G4 77%; E: 2,01 – 2,5mm: 20% of patients with G3 38% and G4 54%; E: 2,51 – 3 mm: 26% of patients with G3 18% and G4 76%. Thus 70% of patients with AAs without dilatation present an E between 1,5 - 3 mm and 96% of them have G3, while in the same range of E 66% of patients with AAs dilated showed 46% with G4 and 16% G3.

Conclusion: AAs of patients with bicuspid valves without aortic dilation at the time of surgery presented less injury in arterial wall as compared with patients with dilated AAs.

PS-06-003

Vulnerability of aortic dissection induced by protease digestion

K. Miura^*, K. Yamashita, Y. Egawa, T. Moriki

^*Hamamatsu Univ School Med, Basic Nursing, Health Science, Hamamatsu Higashiku, Japan

Background & Objective: Dissecting aneurysms of ascending aorta can cause sudden death. To know the pathogenesis of dissection is important to predict future risk. Speed of sound (SOS) through tissues corresponds to tissue rigidity. Susceptibility to protease treatment may simulate future risk of rupture. Aortae of Marfan syndrome (MS) with dissection, non-Marfan syndrome (non-MS) with dissection, and normal autopsy cases were compared with SOS alteration. Moreover, the difference was analyzed by expression of binding extracellular matrix proteins.

Method: Aortic sections in 10 um thickness were digested with collagenases to be followed their SOS. To compare SOS images, LM changes were compared with elastica-Masson stain. To follow alteration of binding proteins, anti-fibrillin-1 and anti-lysyl oxidase (LOX) were stained.

Results: All dissected MS and non-MS aortae showed greater SOS values compared with normal controls. After digestion, SOS of MS reduced rapidly. Non-MS showed two distinct patterns. One was rapidly declined and the other was slowly decreased. In normal controls, SOS of non-atheromatous portions decreased with aging. MS group were unstained with fibrillin-1 but showed conspicuous LOX stain. Non-MS group were positive for fibrillin-1 and focally positive for LOX. Normal younger adults were negative for fibrillin-1 and LOX.

Conclusion: MS with fibrillin-1 deficiency is susceptible to protease digestion. Non-MS contain at least two heterogenous groups about sensitivity to proteases. Both groups increased in rigidity by overexpression of LOX. Vulnerability of dissection induced by proteases may predict future rupture.

PS-06-004

Hypertrophic cardiomyopathy & sudden cardiac death: unexpected revelation

R. Henriques de Gouveia^*, J. S. de Carvalho, F. Branco, C. Cordeiro, O. Moldovan, F. Corte Real

^*INMLCF, Pathology, Coimbra, Portugal

Background & Objective: Sudden Cardiac Death in children and adolescents with Hypertrophic Cardiomyopathy (HCM) ranges 6.6%. The authors present a case where the postmortem multidisciplinary approach was relevant not only from a medical point of view but also for the socio-familial welfare.

Method: A 13-year-old male died suddenly during the sports class, at school.

Results: A thourough postmortem examination revealed cardiomegaly with macro and microscopic characteristics of “Hypertrophic Cardiomyopathy”; advising genetic/familiar study. Meanwhile, additional clinical information was obtained, discovering that the victim had a previous diagnosis of “Familiar (father), Non-Obstructive Hypertrophic Cardiomyopathy”. In such a setting, the Clinical Geneticist asked our Institution for blood samples for molecular studies on the ‘index case’ and consequent evaluation of the familiar risk of other sudden deaths. These new studies not only confirmed the genetic mutation on the father’s side, but also revealed unsuspected genetic alterations on the mothers’ side. This discovery lead to the reorganization of the family clinical counselling and to the reduction of the father’s “guilt” (as he confessed), since he thought to be the only responsible for his son’s disease!

Conclusion: This case highlights the medical, scientific, socio-familial and “human/emmotional” importance of an accurate, specialized and multidisciplinary postmortem examination.

PS-06-005

Chronic aorta dissection: still dangerous?

R. Henriques de Gouveia^*, J. Abecasis, M. Abecasis, J. P. Neves, S. Ramos

^*INMLCF, Pathology, Coimbra, Portugal

Background & Objective: Chronic Aorta Dissection is that with more than 90 days after the onset of symptoms. Its course may be varied, either stable or presenting complications. The authors report four cases of unsuspected chronic dissection.

Method: Four hypertensive patients, three males and one female, aged between 38 and 79-year-old were referred to a Cardiothoracic Center due to ongoing chest pain (n=1), episode of acute chest pain (n=2) - one of which was followed by an acute ischaemic stroke - and also to perform an elective surgery (n=1). The younger patient had polycystic kidney disease. None had history or previous evidence of acute aortic dissection. Emergency imagiologic studies detected lesions of possible type A aortic dissection in three of them and the other had a mitral valve replacement and an ascending aorta aneurysm removal. The aorta segments were sent to anatomo-pathological examination.

Results: Macroscopic evaluation of the specimens showed dead-end false lumen, that in three cases contained acute thrombus. Microscopic observation (complemented with histochemistry and immunohistochemistry) revealed that the false lumen was not recent and was covered by an organized layer of fibrous tissue, upon which the thrombus was seen.

Conclusion: This study reinforces how life-threatening a chronic aortic dissection can be, not only for existing unnoticed but also due to its possible complications, namely being a nidus for thrombosis and thus a source of emboli, leading to ischaemic events and even sudden unexpected death.

PS-06-006

Histopathologic descriptors of degenerative ascending aortic aneurysms according to disease type

V. Agostini^*, A. Jacopo, C. Ricci, B. Corti, L. Di Marco, D. Pacini, O. Leone

^*Ospedale Sant'Orsola Malpighi, Anatomia Patologica, Bologna, Italy

Background & Objective: To assess whether histopathologic descriptors can differentiate disease types in a sizeable number of non-inflammatory/degenerative ascending aortic aneurysms.

Method: We blindly re-evaluated 236 consecutive surgically resected specimens of degenerative ascending aortic aneurysms using the new AECVP/SCVP consensus statement diagnostic criteria. We excluded specimens with moderate/severe atherosclerosis and/or aortitis according to AECVP/SCVP criteria. The study population included: Group1 - 33 pts with genetic disease (mean age 37 yrs, mostly Marfan patients); Group2 - 104 bicuspid aortic valve (BAV) pts (mean age 54 yrs); Group3 - 99 nongenetic/nonBAV pts (mean age 56 yrs).

Results: Overall medial degeneration (MD) was present in all patients; elastic fibre (EF) (99%) and mucoid extracellular matrix accumulation (MEMA) (97%) were the most frequent alterations. Of the three Groups, Group1 had significantly more severe overall MD (Group1: 42.42%; Group2; 8.65%; Group3: 15.15%) (p < 0.0001), as well as more severe intralamellar-MEMA (p < 0.0001) or translamellar-MEMA (p=0.01), and more severe EF thinning-out (p < 0.0001) or EF fragmentation/loss (p< 0.0001). Translamellar collagen increase was almost exclusively seen in Group1 (31.25% vs 1.92% in Group2 and 4.04% in Group3) (p < 0.0001). Interestingly the 15.15% of Group3 severe lesions were found in younger patients (median age 50 vs 59 of group).

Conclusion: Histopathology discriminates genetic versus BAV and nongenetic-nonBAV patients in terms of severity of lesions. This shows that it can produce valuable diagnostic information, especially for the younger patients of Group3 with severe lesions, who should be further tested in view of possible genetic disease.

PS-06-007

Coronary small vessel disease and myocardial fibrosis over the spectrum of hypertrophic cardiomyopathy: an histopathological study

V. Agostini^*, A. Foà, O. Iacopo, F. Cecchi, R. Coppini, C. Ferrantini, S. Pierluigi, G. Vitale, B. Corti, E. Biagini, C. Rapezzi, O. Leone

^*Ospedale Sant'Orsola Malpighi, Anatomia Patologica, Bologna, Italy

Background & Objective: We assessed histopathology of microvascular disease (MD) in hypertrophic cardiomyopathy (HCM) and its relationship with myocardial fibrosis and myocyte alterations and compared pathology findings in obstructive (O)HCM versus endstage (ES)HCM cases

Method: Surgical septal myectomies of 27 patients with OHCM (mean age: 45.4 ± 13.5 yrs) and anterobasal septum specimens of 30 explanted hearts with ESHCM (mean age: 46.8 ± 12 yrs) were retrospectively analysed. MD presence, intimal/medial type and degree (mild: lumen stenosis <30%; moderate: >30% and <60%; severe >60%) were assessed in small intramural coronaries according to lumen diameter: 100-500 micron versus <100 micron. Myocardial fibrosis extent and replacement/interstitial types, and myocyte alterations were recognized.

Results: In 100-500 micron arteries MD was found in 93.3% of ESHCM specimens and in 100% of myectomies, causing severe lumen stenosis in 30% of explanted hearts and 25% of myectomies, and was mixed intimal/medial disease in 80% of ESHCM and 77.8% of myectomies. In <100 micron arterioles MD was less frequent and similar in ESHCM samples (73.3%) and myectomies (77.8%). Fibrosis was more frequent in explanted hearts (36.8% ± 20.4 vs 12.8% ± 8.46) (p<0.001), prevalently replacement type (53.3% vs 14.8%) (p=0.005). Diffuse myocyte vacuolization was found in only ESHCM specimens (23,3% vs 0, p=0.011)

Conclusion: MD is present over the entire HCM spectrum suggesting that it is a constant finding in HCM. Although myocardial fibrosis is present in both ESHCM and OHCM, replacement fibrosis along with advanced myocyte abnormalities are distinctive patterns in ES patients.

PS-06-008

Correlation of histological patterns in temporary artery biopsies with clinical symptoms and analytical data

C. Gonzalez Vela^*, R. Mazorra Horts, D. Prieto Peña, A. Onaindia, M. Calderon Goercke, V. Secadas Diaz, J. Gonzalez Vela, R. Blanco Alonso, M. A. Gonzalez-Gay

^*Hospital de Valdecilla, Santander, Spain

Background & Objective: Giant cell arteritis (GCA) is a systemic vasculitis that affecting large and medium vessels, mainly the temporal artery and other arteries of extracranial localization. We review a series of patients with clinical suspicion of GCA proved by a positive temporal artery biopsy (TAB). Our objective is to review the histologic inflammatory patterns in the TAB and their possible correlation with analytical and clinical data.

Method: Prospective study of patients with positive TAB between January of 2016 until January of 2018. Clinical data, included: age, sex, symtomatology, physical examination of the temporal artery, ESR, CRP, hemoglobin. Positive biopsies were classified into four categories: a) inflammation limited exclusively to the small vessels of the adventitia (SVV); b) vasa vasorum vasculitis (VVV); c) inflammation limited to the adventitia (ILA); and d) transmural inflammation (TMI). The presence of giant cells, trombosis and distrophic calcification was also noted.

Results: There were 12 female (57%) and 9 male (43%) patients with a positive TAB, with an average age of 78.9 years. Most of the TABs (90.5%) presented TMI, and only 2 cases (9.5%) had ILA. There were no cases with SVV or VVV. There were no significant differences between the correlation of the clinical and analytical data and the 2 patterns of inflammation observed. In all cases of ILA, the patients had headache, visual symptoms, jaw claudication, systemic symptoms and polymyalgia rheumatica. There were no cases of visual loss.

Conclusion: In our series we didn’t observed differences between the patterns of inflammation and the analytical and clinical data. It is important to know these patterns of inflammation in the TAB to avoid false negatives.

PS-06-009

Mature cardiac myocyte hamartoma. Case report and review of literature

M. Fernandes^*, R. Portugal, E. Rios

^*Hospital de São João, Anatomia Patologica, Porto, Portugal

Background & Objective: Primary cardiac tumours are rare and usually benign. Among these, hamartoma of mature cardiac myocytes (HMCM), are extremely rare, with only 23 cases reported in the literature. First described by Tanimura et al. in 1988, HMCM is characterized by localized, disorganized and hypertrophied mature myocytes. Herein we report a further case of HMCM and review the literature on issue.

Method: A 22-year-old woman, complaining of dyspnea and progressively worsening chest pain, was found to have on echocardiography a homogeneous intracardiac mass measuring 31x14mm on the wall of the right atrium. A right atrial resection was done.

Results: The surgical specimen measured 50 x 47 x 6 mm and weighted 24.4 g. Histologic examination of the lesion revealed striking hypertrophy of the myocytes, variably interspersed among interstitial fibrosis, blood vessels and scant adipose tissue. Additionally, scattered inflammatory cells comprising lymphocytes and histiocytes were seen. The myocytes showed disorganization, occasional vacuolization, and marked degenerative features with nuclear irregularities and hyperchromasia. The diagnosis of HMCM was made. After two years follow-up the patient is asymptomatic without signs of recurrence.

Conclusion: HMCM may be detected at any age or location in the heart, preferentially affect males, patients are usually symptomatic, and rarely may be associated with sudden death. Our case was similar to others described in the literature. Since HMCM share common features with other cardiac tumours, clinical diagnosis is quite difficult; therefore pathologists play an important role in the recognition of this entity. Surgery is an effective treatment (even after incomplete resection) in symptomatic patients.

Monday, 10 September 2018, 09:30 - 10:30, Exhibition Hall I/II

PS-07 | Dermatopathology

PS-07-001

Cutaneous syncytial myoepithelioma: a case report

M. Marques Oliveira^*, C. Estima Fleming, R. Amorim, L. Brochado Ferreira, J. Ricardo Brandão, B. Fernandes, N. Jorge Lamas, J. Raposo, F. Moreno, J. Ramón Vizcaíno

^*Centro Hospitalar do Porto, Dept. of Anatomic Pathology, Portugal

Background & Objective: Myoepithelial tumours arising in the dermis, subcutaneous fat or soft tissue are exceedingly rare. Commonly, cutaneous myoepitheliomas behave in a benign fashion, however, local recurrence and metastasis have been documented. We aim to report a case of a morphologically distinct variant, designated cutaneous syncytial myoepithelioma, illustrating its histological and immunohistochemical characteristics and discussing possible differential diagnosis.

Method: A 31-year-old man presented with a 5 mm papular skin lesion, located in the right harm, treated by local excision. Specimen was routinely processed, sections stained with haematoxylin-eosin and immunostains performed.

Results: Histologically the tumour was located in the dermis, displaying expansile, solid sheet-like growth. Tumour cells were uniformly sized, epithelioid to histiocytoid, with ovoid to spindled shaped nuclei and eosinophilic syncytial cytoplasm. Nuclei were vesicular, with fine chromatin, small or inconspicuous nucleoli and no significant pleomorphism. Intranuclear pseudoinclusions were frequent. Mitoses were scanty and necrosis was absent. The overlying epidermis displayed orthokeratosis. Immunohistochemical study showed diffuse positivity for EMA, S-100 protein and SMA. Keratin staining was multifocal. The deep margin was involved by the tumour.

Conclusion: Myoepithelioma`s morphology may lead to diagnostic pitfalls, particularly in the case of a dermal lesion with spindle or epithelioid cells, thus emphasizing the importance of applying a suitable immunohistochemical panel when a myoepithelial neoplasm is suspected. Since reliable criteria for malignancy are still not established and behavior is unpredictable, patients diagnosed with these lesions should maintain a long-term follow-up. At the time of writing, 11 months after surgery, the patient was alive and well, with no local recurrence identified.

PS-07-002

Diagnostic efficiency of CD1a immunostaining in the diagnosis of cutaneous leishmaniasis

A. Sassi^*, I. Chelly, A. Zehani, B. Chelly, A. Souissi, N. Saidi, H. Ben Mahjouba, M. Mokni, A. Bouratbine, S. Haouet, N. Kchir

^*Salah Azaiez Institute, Pathology, Tunis, Tunisia

Background & Objective: CD1a is useful to detect amastigotes in Old World cutaneous leishmaniasis (CL) since it is acquired by leishmania from the host dendritic cells during the inflammatory response. However, its accuracy is unknown. Our aim is to study the efficiency of immunohistochemistry with CD1a in the diagnosis of CL.

Method: We retrospectively reviewed skin biopsies of proven CL based on direct examination, culture and kinetoplast DNA-polymerase chain reaction (PCR) from paraffin-embedded skin sections. For PCR analysis, specimens with a threshold cycle ≤ 32.8 were considered positive. Immunohistochemistry with CD1a (MTB1 clone) was performed. Cases without tissue for CD1a staining were excluded.

Results: Twenty-eight positive skin biopsies were included: 11 positive on direct examination and 17 positive on PCR. CD1a staining was positive in amastigotes in 27/28 cases (96%). All cases (5/5) of zoonotic CL (Leishmania Major) were CD1a positive and 96% of sporadic CL (L. Infantum) were CD1a positive. In comparison with PCR, the sensitivity, specificity, positive predictive value and negative predictive value of CD1a immunostaining were 96.4%, 50%, 93.1% and 66.7%, respectively.

Conclusion: Prior studies have reported a higher sensitivity for CD1a staining in Old World species of leishmaniasis than in New World cases (44). Our results confirm CD1a (MTB1 clone) has a high sensitivity and can be useful to highlight amastigotes in biopsies of Old World cutaneous leishmaniasis. However, there are significant limitations to this screening approach as CD1a has a low specificity in comparison with PCR from paraffin-embedded blocks.

PS-07-003

Clinical case: alopecia - unusual precursor B lymphoblastic lymphoma clinical manifestation

A. Ruminaite^*, J. Makstiene

^*LSMUL KK, Pathology, Kaunas, Lithuania

Background & Objective: To introduce a case-based scientific research of unusual clinical manifestation of skin precursor B lymphoblastic lymphoma (B-LBL)/leukaemia (B-ALL) in a 40-year-old female patient with alopecia. This type of lymphoma is especially rare in skin as a primary tumour and primarily affects children under six years of age (more than 75 % of cases).

Method: In 2014, a 40-year-old female was appointed to dermatologist after six months of multiple alopecia patches on her scalp in frontal and parietal areas.

Results: Pathology diagnosis from the first skin biopsy was B-LBL/B-ALL. On PET-CT scan metabolicaly active lymphoproliferative disease was found on the top of the head, both sides of the shoulders and soft tissues of thoracic wall, as well as in a right ureter. High dose-CHOP chemotherapy was initiated consisting of cyclophosphamide, doxorubicin, vincristine and prednisone. After six months control PET-CT scan demonstrates partial response to treatment. Reconsultation of dermatologist revealed new multiple skin nodules. Pathology diagnosis remains the same as a first one.

Conclusion: Alopecia is autoimmune disorder characterized by patches of non-scarring alopecia usually affecting scalp and body hair. Approximately 2% of people worldwide have this disorder. Rarely one of alopecia cause could be malignant tumour. Precursor B lymphoblastic lymphoma (B-LBL)/leukaemia (B-ALL) constitutes approximately 10% of cases of lymphoblactic lymphoma and less than 10% of all skin lymphomas. Around 80-85% lymphoma cases are of precursor B-cell phenotype. The B-LBL frequently present in the skin, lymph nodes and bone. In adults, B-ALL overall complete remission rate is 60-85%.

PS-07-004

Driver mutations, PD-L1 expression and clinicopathological correlation in desmoplastic melanomas

C. Fuster Anglada^*, S. Vera, G. Frigola, A. Garcia, S. Puig, L. Alòs

^*Hospital Clínic de Barcelona, Anatomic Pathology, Spain

Background & Objective: Desmoplastic melanomas (DM) are a rare subtype of spindle cell malignant melanoma, characterized by a delay in the diagnosis and frequent local recurrences. The aim of the study was to collect the clinicopathological characteristics of a series of 27 DM along with investigating actionable driver mutations and the expression of PD-L1.

Method: From formalin-fixed samples hot spot mutations of genes AKT1, ALK, BRAF, CTNNB1, DDR2, EGFR, ERBB2, ERBB4, FBXW7, FGFR1, FGFR2, FGFR3, KRAS, MAP2K1, MET, NOTCH1, NRAS, PIK3CA, PTEN, SMAD4, STK11 and TP53 were investigated in 11 cases using NGS Oncomine Focus Assay (Thermo Fisher Scientific). In addition, in 10 cases BRAF mutations were studied by RT-PCR. PD-L1 expression was investigated by immunohistochemistry using 22-C3 antibody (DAKO) in 23 cases.

Results: Tumours occurred in 20 men (74%) and 7 women (26%), with a median age of 65 years. The most frequent location was the head and neck region. Twenty tumours were histologically pure and 7 mixed-type (with conventional melanoma component). Lymphatic and haematogenous metastases were more frequently found in mixed-type DM. Overall, 33% of DM harboured BRAFV600 mutations; 45,5% TP53 mutations; 9% MET mutations and 0SMAD4 mutations. Seven out of 23 cases expressed PD-L1 (30%).

Conclusion: In conclusion, the mixed-type DM have a worse outcome. BRAFV600 mutations are more frequently found in this DM type; whereas pure DM are usually BRAF wild-type and have frequent TP53 mutations. We have not found a correlation between the PD-L1 expression with the clinicopathological characteristics of DM.

PS-07-005

Chondroid syringoma: analysis of clinical-pathological features. A series of 12 cases

I. M. de Lara Simón^*, J. L. Sanz Trenado, L. González Ruiz, M. García Arpa, P. Montero Pavón, V. Herrera Montoro, M. Franco Muñoz, D. Castro Corredor, P. Nuñez Guerrero, C. C. Ramos Rodríguez, L. M. González López, F. Martín Dávila, R. López Pérez

^*General Hospital Ciudad Real, La Carolina, Spain

Background & Objective: Chondroid syringoma (CS) or mixed tumour (MT) of the skin is a rare, bening neoplasm. The most frequent location are head and neck. It has an inespecific clinical debut and the diagnosis is histopathological. We present 12 patients with skin lesions with pathological diagnosis of CS and their clinical-pathological features.

Method: A search with a diagnosis of MT is performed through the database of the Pathological Departament of the General University Hospital of Ciudad Real (GUHCR) in 8 years, and medical historial are consulted with the electronic program of the Dermatology Departament of the GUHCR. Clinical data and histopathological features of the skin lesions were collected and reviewed.

Results: 12 cases coded as MT of the skin were retrieved. 3 women and 9 men between 29 and 73 years old. Most lesions were on face and scalp, and most frequent presentation was a skin-colored subcutaneous nodule. None was clinically suspected. Histologically, a cellular proliferation in dermis was observed, it was constituted by epithelial and mesenchymal origin cells with a background fibromyxoid matrix and adipose metaplasia in almost all cases. 11 corresponded to apocrine type and 1 to eccrine type. No recurrences were found.

Conclusion: CS should be considered in the differential diagnosis of subcutaneous nodules in head and neck in middle-aged patients. Total excision is the preferred treatment. CS has good prognosis and low potencial of recurrence. It´s a rare tumour whose diagnosis is histological, and we provide data of clinical-pathological correlation and practical histopathological data for help to the differential diagnosis.

PS-07-006

Variation of dendritic cells distribution patterns in mycosis fungoides vs. inflammatory dermatosis

C. Costras^*, C. Constantin, L. Nichita, L. Sticlaru, G. Turcu, V. Nichita, O. Stefan, I. Frincu, B. Harsan, M. Neagu

^*Colentina Clinical Hospital, Pathology, Bucharest, Romania

Background & Objective: Our study aims to identify and characterize variation of distribution of dendritic cells in inflammatory dermatosis and in mycosis fungoides, useful in differential diagnosis and understanding the pathophisiology of these lesions.

Method: Our study included a cohort of 78 patients: 22 with psoriasis, 26 with spongiotic dermatitis (SD) and 30 with mycosis fungoides (MF). Their diagnostics were based on histopathological and imunohistochemical stains. Specific markers for DCs were performed (CD1a, Langerin and CD11c), in order to evaluate the density, localization and distribution pattern of DCs.

Results: In all cases, a high number of DCs was found in epidermis diffusely distributed. The number of intraepithelial DCs was higher in inflammatory dermatosis. Second more frequent pattern was diffuse distribution in papillary dermis. More than a half of inflammatory dermatoses had both diffused DCs in epidermis and in papillary dermis. In comparison to SD and MF, many cases of psoriasis had nodular distribution of DCs in papillary dermis. Only in MF were found DCs dispersed in reticular dermis.

Conclusion: Distribution patterns of DCs emphasized by immunohistochemistry may help in MF and inflammatory dermatosis differential diagnosis.

This paper is partially supported by UEFISCDI, Romania, grant PN-III-P4-ID-PCE-2016-0641 (Project No 183/2017).

PS-07-007

Malignant blue melanoma: an institution experience in 4 cases

P.-I. Stinga^*, C. Popp, M. Cioplea, A. Cioroianu, S. Dutulescu, R. Andrei, C. Dumitru, V. Chitu, D. Boda, C. Caruntu, S. Zurac

^*Colentina Clinical Hospital, Pathology, Bucharest, Romania

Background & Objective: Malignant blue melanomas (MBM) are melanomas arising in association with blue nevi (BN) or simulating BN, representing a heterogeneous, controversial set of melanocytic tumours. No consensus exists for diagnostic histological criteria or prognostic indicators. MBM differential diagnosis includes mainly atypical BN, melanocytoma and metastatic melanoma.

Method: 212 BN and related tumours were diagnosed in 9 years in our hospital; they include 7 atypical BN and 4 MBM.

Results: Mean MBM patient age was 44 years (range:17-73); there were 2 males and 2 females. The tumours were commonly located on the trunk region (50%). MBMs were typically situated in mid/deep dermis with frequent subcutaneous involvement, composed of large, variable pleomorphic, spindled and/or epithelioid cells. Mean Breslow thickness was 5,28 mm (range: 2,85-6,8 mm); mean mitotic figure count was 5/mm2 (range: 2-11/mm2); one tumour was ulcerated; two MBMs had lymphovascular invasion and 2 perineural invasion. One tumour was negative for HMB45 staining; all cases had Ki67 proliferation index >10%. One MBM patient died of disease (thigh tumour with V600 B-raf mutation and gain of chromosomes 3q,5,8,15,18,20,22,X revealed by comparative genomic hybridization; inguinal lymph nodes and liver metastases after 2.5yrs; vemurafenib treatment till death, 5yrs after first diagnosis); all the other 3 patients are alive and free of disease (4, 46, 44 months follow up).

Conclusion: In our study, MBM showed a predilection for trunk region, large Breslow index and frequent lymphovascular and perineural invasion; overall prognosis apparently is more favourable than classic melanoma with similar stage.

This work was supported by a grant of Romanian-Ministery-of-Research-and-Innovation, CCCDI-UEFISCDI, project number 61PCCDI/2018 PN-III-P1-1.2-PCCDI-2017-0341, within PNCDI-III.

PS-07-008

Cutaneous amyloidosis as major manifestation of systemic AL-amyloidosis

I. Gullo^*, J. Pardal, J. Magalhães, S. Lopes, F. Azevedo, J. M. Lopes

^*Centro Hospitalar São João, Pathology Dept., Porto, Portugal

Background & Objective: Cutaneous involvement in acquired systemic immunoglobulin light chain (AL) amyloidosis occurs in 30-40% of patients. We report a case of systemic lambda-type AL-amyloidosis, revealed by exuberant persistent cutaneous lesions.

Method: A 70-year-old Caucasian man was referred to our hospital due to hard tight edema, and plaque-like, purpuric and ecchymotic lesions involving the anogenital and inguinal areas, with asthenia and weight loss in the last month. There was no evidence of macroglossia or peri-orbital purpura. Initial routine laboratory tests were within normal values and skin biopsies were performed.

Results: Histology showed diffuse homogenous, hyaline deposits in the dermis, subcutis and vessel walls, consistent with amyloid (Congo-red/polarised light) of the AL-type (immunohistochemistry). The patient developed aspiration pneumonia, after a colonoscopy, complicated by septic shock and multi-organ failure. Serum protein electrophoresis showed no monoclonal peak, but free-light-chain evaluation revealed: lambda - 297mg/L (normal: 110-240mg/L); kappa - 51mg/L (normal: 200-440mg/L) and kappa/lambda ratio - 0.17 (normal: 1.35-2.65), consistent with light-chain plasma cell dyscrasia. Ecocardiography, stage 3/4 chronic kidney disease and abdominal/pelvic CT-scan findings were consistent with advanced systemic AL-amyloidosis. Despite best supportive care, the patient died five months after diagnosis.

Conclusion: AL-amyloidosis can evolve progressively to advanced stages, without specific clinical features, but macroglossia and peri-orbital purpura (<1/3 of cases), not present in our case, should suggest this diagnosis. Clinicians should be aware that cutaneous involvement, despite occasional, may occur in flexural skin, that should be evaluated in a skin biopsy, to establish the diagnosis of AL-amyloidosis, as in the herein case.

PS-07-009

Compound blue nevus (Kamino Blue Nevus): an unusual benign melanocytic lesion

B. Fuertes Negro^*, H. Iliev Iliev, A. Valero Torres, L. Pérez Domingo, T. Martínez-Boyero, E. Mejía Urbáez, F. Felipo Berlanga, J. M. Rodríguez Artigas, R. González Tarancón

^*HCU Lozano Blesa, Pathology, Zaragoza, Spain

Background & Objective: Blue nevi are a subset of melanocytic proliferations containing cells reminiscent of the embryonal neural crest–derived dendritic melanocytic precursors. They are common specimens in a general pathology practice, but some of their rare variants may pose diagnostic difficulty. An example of one of these variants is the Compound Blue Nevus (CBN) or “Kamino Blue Nevus”.

Method: We present a case of a 42-years-old female with a pigmented lesión in the right submammary región. An exision was performed, due to an increase in size in the course of the previous year.

Results: The surgical specimen was a 6 mm punch biopsy, with a 4 mm brownish, well delimited papule in its center. Histologically, melanocytic proliferation was observed at the level of the papillary and superficial reticular dermis. The melanocytes had a dendritic morphology, with a vaguely congenital distribution. A minute intracytoplasmic melanin pigment granules were identified. In the epidermis, a junctional melanocytic component, in the form of single cells was found, without evidence of theca formation. Immunohistochemistry highlighted the unique histopathologic feature of CBN, namely, single dendritic melanocytes at the dermoepidermal junction with striking intraepidermal prolongations.

Conclusion: CBN is a distinctive variant of blue nevus that may mimic cutaneous melanoma both clinically and dermoscopically. The junctional component of linear melanocytic proliferation in a blue nevus is a rare finding, but an important diagnostic clue to the recognition of CBN.

PS-07-010

Cellular dermatofibroma – a challenging diagnosis

A.-M. Vrancianu^*, D.-A. Costache, R.-Z. Bulf, S.-A. Zurac, R. T. Andrei

^*Colentina Clinical Hospital, Pathology, Bucharest, Romania

Background & Objective: Cellular dermatofibroma (CDF) is a dermatofibroma variant with higher rate of local recurrence and, exceedingly rare, distant metastases.

Method: We reviewed 21 cases of CDF diagnosed between 2012-2017 in our department – 6.7% of a total of 312 dermatofibromas; immunohistochemistry for CD34, SMA, Desmin, S100 protein, CD68, factor XIIIa and Ki67 was performed.

Results: The lesions are mostly located on the limbs (upper 52.38%, lower 33.33%, the remainder on trunk 14.28%) with dimensions between 0.6/0.4/0.4-2.5/2.5/2cm; none on head and neck; 3 cases were associated with previous trauma. Male-to-female ratio was 1:2; median age 42 (between 15-64 years). Histopathologically, the lesions were deeply seated with evident grenz zone, highly cellular, with densely fascicular growth pattern, tend to be very infiltrative, 11 extending into the superficial subcutis, 6 being incompletely excised and 4 ulcerated. Typical mitoses were common, 14 cases showed 1-6 mitoses/10HPF; central necrosis was found in 2 cases. Focal positivity for CD34, SMA and Desmin was noted in a minority of cases. Expression of Factor XIIIa was a constant feature. Ki67 index ranged between 0-5%. S100 and CD68 were negative.

Conclusion: Given the high rate of recurrence and the possibility of metastases, even extremely rare, complete surgical excision is mandatory and correct identification of this variant is important for differential diagnosis and prognosis, especially to avoid misdiagnosis of a possibly aggressive lesion such as dermatofibrosarcoma protuberans and leiomyosarcoma. Factor XIIIa is a valuable immunohistochemical marker for differential diagnosis.

This work was supported by a grant of Romanian-Ministry-of-Research-and-Innovation, CCCDI-UEFISCDI, project number 61PCCDI/2018 PN-III-P1-1.2-PCCDI-2017-0341, within PNCDI-III.

PS-07-011

Hashimoto-Pritzker histiocytosis: presentation of a case and literature review

P. Montero Pavón^*, C. Ramos Rodríguez, L. González Ruiz, J. L. Sanz Trenado, I. M. de Lara Simón, V. Herrera Montoro, L. González López, N. Villasanti Rivas, R. López Pérez

^*Hospital General Ciudad Real, Spain

Background & Objective: Hashimoto-Pritzker histiocytosis (HPH) is a entity discribed in 1973 as a subtype of Langerhans histiocytosis. It is an infrequent, usually solitary, congenital, cutaneous lesion but always self-healing with an excellent prognosis. We review and analyze the indexed literature to date.

Method: Using the PSPP statistical program, we compiled all the HPH cases published in the PubMed database, analyzing the variables sex, age, lesion size, location, type of injury, resolution times, follow-up and extracutaneous commitment.

Results: We compiled 84 articles describing a total of 139 cases. We found that HPH cases showed a similar proportion of men and women. In 85% of the cases, the lesions were congenital. The size of the lesions was between 5 and 10 mm in 63% of the cases, presenting more frequently as nodular lesions. In 57% the lesions were multiple, with no predilection in their corporal distribution. Only 7% presented extracutaneous involvement, with the affected organs being bone, liver, kidney and lung. The lesions disappeared more frequently between 2 and 6 months of age.

Conclusion: HPH is a relatively recent and infrequent entity that, due to its self-resolution, is likely to be underdiagnosed, with lesions disappearing within a few months of birth.

PS-07-013

Papular epidermal nevus with “skyline” basal cell layer (PENS), and PEN syndrome in triplets siblings

V. Velasco Benito^*, M. R. Gonzalez Hermosa, L. Peña Merino, A. Barrutia Borque, L. Andres Alvarez, A. Fernandez de Larrinoa, L. Mosteiro Gonzalez, M. Saiz Camin, V. Caamaño Villaverde, M. Gonzalez Vadillo, A. Gaafar Eleraky, A. Nogueira Alonso, D. Parron Collar, G. Garcia de Casasola, E. Fernandez Lomana, M. Atienza Robles, I. Diaz de Lezcano, S. Malaxetxebarria Unibaso, A. Marcos, A. Nogueira Gregorio

^*Hospital Universitario Cruces, Anatomía patológica, Barakaldo, Spain

Background & Objective: Classical epidermal nevi can have an inespecific or subtle histologic pattern that usually needs clinical correlation. However, papular epidermal nevus with “skyline” basal cell layer has characteristic histological features that allow pathologists to make specific diagnosis. 50% of the patients have PENS syndrome, which includes neurological and ophthalmological anomalies apart from polygonal shaped hyperkeratotic papules since birth.

Method: Triplets siblings came up to dermatology department with multiple papular skin lesions in trunk, neck and extremities since birth. The two brothers developed neuro-ocular anomalies; one had squint and mental retardation, and the other one language development problems. Female patient only has skin lesions up today. Sin biopsies were performed of two patients.

Results: Histological examination showed broad, rectangular rete ridged achantosis with characteristic arranged basal cells with palisated nuclei. Clinical data and additional test (MR) were recopilated and studied, then brothers were diagnosed as PENS syndrome while female has PENS limited to skin.

Conclusion: Both histological and clinical features of PENS are diagnostic, hence clinicians and pathologist should be aware of this syndrome to achieve early diagnostic and neuro-development evaluation or treatment. PENS syndrome is not related to epidermal nevi syndrome and has no FGFR3 nor PIK3CA mutations.

PS-07-014

Protein p16 role in seborrheic keratosis

E. Rudenko^*, A. Aleksandrova, V. Smolyannikova, V. Filatova

^*FSAEI of Higher Education I.M., Pathology, Moscow, Russia

Background & Objective: Seborrheic keratosis (SK) is a disease of unknown etiology and pathogenesis. Details of the cell cycle destruction by the SK are not revealed despite a number of studies.

Method: To study the p16 expression in patients with multiple and single SK. An immunohistochemistry test with monoclonal antibodies to p16 was accomplished, 20 SK served as a material for the test, which were obtained from patients with multiple SK – 10 patients, and single SK (not more than 10 elements on the skin) - 10 patients. Clinical examination of patients was being conducted, using data from the anamnesis of concomitant somatic pathology.

Results: Intense cytoplasmic and nuclear staining of tumour cells was revealed by individuals with multiple SK in 70% by immunohistochemical test with monoclonal antibodies to p16, 30% of the staining was moderate, diffuse. A positive reaction with antibody to p16 was diffuse, weak by patients with single SK in 80% of the cases, stain of the single cells of the basal layer nucleus was recorded. In 20% the colour of the cells cytoplasm was intense, but as separate focuses, in these cases was revealed insulin resistance. The presence of insulin resistance was revealed from anamnesis by all patients with multiple.

Conclusion: The connection was found between the intensity of the p16 expression and the prevalence of SK. Given the presence of insulin resistance in the anamnesis of patients with multiple SK, an assumption was made about an indirect effect of the p16 expression on hyperinsulinemia. The presence of focal intense reactions with antibodies to p16 by patients with single SK can serve as a predictor of eruptions dissemination in future.

PS-07-015

Squamous cell carcinoma in situ associated with cutaneous infiltrate of chronic lymphocytic leukemia

A. I. Lavado Fernández^*, E. Ortega Pastor, J. Herrero Santacruz, L. Francés Rodríguez, J. C. Escribano Stable, A. D. Lozano Salazar, M. Serrano Jiménez, V. López García, A. Martínez Torres, A. Martínez Lorente, M. Sansano Botella, D. Martínez García, D. Almecija Furio, E. Rico Alcolea, E. Casanovas Carnicer, M. Belmonte Fernández, E. García Villegas, P. Pomárez Pérez, A. Bosch Angresola, A. Cervetto Bautista, M. d. Mar Sánchez Sánchez Ortuño, M. Tárraga Ballester, E. Nogueiras Fernández, P. García Fernández, A. Fernández Moreno, B. Riquelme Bernabeu, M. d. Mar Botella Pujalte, D. Pastor López, S. Rey Nodar, A. A. Ramírez Bosca

^*Hospital Vinalopó, Hospital de Torrevieja, UCAM, Malaga, Spain

Background & Objective: Chronic lymphocytic leukaemia (CLL) is a neoplasm characterized by clonal expansion of B-lymphocytes with distinct morphology and immunophenotype. Although CLL typically follows an indolent course, it is well established that patients have a greater increased risk of developing a second malignancy mostly skin cancer non-melanomas due to ultraviolet radiation exposure and immunosuppression. CLL is the most common type of leukemia in adults, while dermatological literature reporting CLL is limited.

Method: We present an 89-year-old spanish woman with CLL and basal cell carcinoma. She was referred to a dermatologist who noted an erythematous crusted patch on the right temple. There was no clinical suspicion of clinical involvement by CLL. There was no improvement after treatment with topical ingenol mebutate, so a biopsy was obtained.

Results: A conventional histologic examination revealed atypical keratinocytes and a dense dermal infiltrate of monomorphous, small lymphocytes with round nuclei, a regular chromatin dispersion pattern and scarce cytoplasm. The neoplastic lymphocytes were shown to be CD20+ and CD5+. CD 23 and CD43 were unreactive.

Conclusion: CLL characterized by highly biological heterogeneity and variable clinical course. CLL infiltrating the skin is uncommon and can present in many different ways. A dense sheet of monomorphous lymphoid cells should raise the possibility of leukemic infiltration of the skin and may surround epithelial neoplasms such as basal cell carcinoma and squamous cell carcinoma. Treatment is only indicated in case of active disease and may be involved in the keratinocyte dysplasia. The pathogenic relationship between CLL and skin neoplasia is unclear.

PS-07-016

Wrist paraffinoma after self-injection of vaseline: a case report of very late formation

I. Beinarovica^*, J. Krustins, V. Groma

^*Riga Stradins University, Faculty of Medicine, Latvia

Background & Objective: Paraffinoma is the rare condition characterized by a replacement of normal subcutaneous tissues by cystic spaces. The changes develop after injection of oily substances and usually have the facial and penile localization.

Method: We present a case of 39-year-old man with paraffinoma of the right wrist dorsal surface after vaseline self-injection performed 25 years ago. The patient has a history of methadone addiction and chronic virus hepatitis C. Three weeks prior his visit patient had superficial wrist injury. Physical examination revealed local inflammation, dermal necrosis, ulceration and solid subcutaneous mass along the wrist dorsal surface reducing the extension of fingers. Debridement surgery followed by examination of removed tissues by light and electron microscopy was performed.

Results: Histopathological examination revealed panniculitis characterized by variably sized and shaped cysts with a Swiss cheese appearance surrounded by multinucleated giant cells and lymphohistiocytic infiltrates. Ultrastructurally, histiocytic intracellular and extracellular vaseline-containing vacuoles were demonstrated. Surgical excision requiring further reconstruction of the patient’s wrist dorsal surface was performed, but he escaped from the hospital next day. The patient was admitted to the hospital with a repeated infection after two months and underwent another debridement surgery. Wet-to-dry dressings were applied to obtain granulations of the defect.

Conclusion: Wrist paraffinomas are ultra-rare conditions requiring damaged tissues excision followed by reconstructive surgeries for enhancing wrist functions. Reconstruction is impracticable due to patient’s attitude. Complications associated with oily injections may be extremely delayed in spite of putative immunosuppression.

PS-07-017

Acral nevus (melanocytic acral nevus with intraepidermal ascent of cells) in a child. Report of a case and differential diagnosis

C. Cacchi ^*

^*Uniklinik RWTH Aachen, Pathology, Germany

Background & Objective: Acral melanocytic nevi may represent a diagnostic challenge having sometimes worrisome morphological features that overlap with melanoma. Herein we describe a case of acral nevus in a very young child and the differential diagnostic features with melanoma.

Method: A 3 years old child, with a dark brown lesion on the foot, after clinical examination, was referred to surgery. Macroscopic, the resected skin specimen showed a brown, light irregularly shaped lesion of 5x4 mm in diameter. Microscopic examination was performed.

Results: Histologically, at low magnification, the melanocytic tumour was composed of junctional melanocytes, with only a few dermal melanocytes. The lesion showed a good symmetry with no mitosis or fibrotic change. Focally, „spotty" pigment in the stratum corneum was also noted. Interestingly, there was presence of scatter melanocytes throughout the epidermis, suggesting a pagetoid spreading (so called "Maniac nevus"). However, these pagetoid melanocytes had banal, bland morphology. There was no irregular lympho-histiocytic infiltrate in the dermis.

Conclusion: Acral melanocytic nevi may present atypical characteristics and constitute a difficult diagnosis. A careful evaluation of histologic and clinical features such age of the patient and size of the lesion, are of paramount importance to avoid overdiagnosis of melanoma.

PS-07-018

BRAF mutation testing as a diagnostic tool of undifferentiated/dedifferentiated melanoma

A. Szumera-Cieckiewicz^*1,2, M. Chraszczewska, A. Dansonka-Mieszkowska, A. Tysarowski, M. Prochorec-Sobieszek

^*1Cancer Center and Institute of Oncology, Warsaw, Poland

^*2Institute of Haematology and Transfusion Medicine, Warsaw, Poland

Background & Objective: BRAF mutations are associated with malignant melanomas (MM) in about 40-50% of cases with V600E which comprises up to 90%. MM, particullary metastases, tend to present with an aberrant immunohistochemical (IHC) features and lack an evidence of melanocytic differentiation. Histologically, these cases are more likely to be poorly differentiated including i.e. spindled or sarcomatoid types.

Method: From archive data bases 9 cases of MM with a second undifferentiated malignancy/metastatic MM were identified. The broad panel of MM IHC were performed and BRAF mutation status was investigated whenever the formalin fixed paraffin embedded material was available.

Results: A group of 9 cases of metastatic MM, with male to female ratio 3:6 and median age 44 years (range 27 to 57 years). Sites of involvement were soft tissue (5/56%), bone (1), axillary lymph nodes (1), adrenal gland (1) and ovary (1). Mean time from primary MM to metastasis was 55 months (range 20 to 108 months). All cases showed a partial or complete loss of the IHC melanocytic markers; all of them were negative for HMB-45 (0/9) and Melan A (0/9) whereas lack of S100 was observed in 6 cases (3/9). BRAF V600E mutation was detected in 6/9 cases (67 %) respectively.

Conclusion: The presence of BRAF V600E mutation in poorly differentiated or undifferentiated malignancies should be helpful diagnostic tool for patients with MM history. Undifferentiated/dedifferentiated metastatic melanoma is likely under-recognized and frequently mistaken for undifferentiated sarcoma or other neoplasms. BRAF V600E is a helpful surrogate marker in classifying such difficult cases and is important in choosing treatment regiments.

PS-07-019

Correlation between genetic mutations and clinicopathologic features in a series of acral melanomas

I. Busmanis^*, P. Y. Tan, L. Oon

^*Singapore General Hospital, Histopathology L10, Singapore

Background & Objective: Oncogenic activating BRAF mutations, seen in 40-60% of melanoma, are also seen in acral lentiginous melanoma (ALM), although at a lower incidence. This is the first study from Singapore to correlate molecular findings in acral melanomas with clinicopathologic features and compare with other Asian data.

Method: 142 cases of melanoma with molecular analysis for mutations in exon 15 of the BRAF gene, and exons 9,11,13, and 17 of the ckit in genomic DNA by polymerase chain reaction amplification and direct Sanger sequencing, were retrieved from the Singapore General Hospital files (2007-18)

Results: Of 142 cases, 55 (38%) were cutaneous, 45 (32%) acral and 42 (30%) mucosal. Of 45 acral tumours, 36/45 (80%) were BRAF negative and 9/45 (20%) positive. Of 28 acral cases with ckit mutational analysis, 21/28 (75%) were ckit negative, 5/28 (18%) positive, and 2/28 (7%) inconclusive. The majority of BRAF positive were Chinese ethnic group (6/9), female (7/9), mean age 56 years, located at non-pressure sites (7/9) and the foot (7/9. Tumours which were positive with either BRAF or ckit mutations showed similar incidence of ulceration (60%), lower than cases of BRAF negative (75%) or ckit negative (71%) tumours. ckit positive tumours had the highest incidence of metastasis (80%), and ckit negative the lowest (43%). No major differential was seen in the incidence of metastasis between BRAF positive or negative cases.

Conclusion: The BRAF positive mutation rate in Singaporean ALM was comparable with data from China, Korea, Taiwan and Japan. Findings suggest dyssynchronous incidence of ulceration and metastasis.

PS-07-020

Screening for mismatch repair mutations in sebaceous neoplasm

I. J. Expósito Afonso^*, L. I. Martínez Blanco, I. González Villa, S. Cáceres García, C. Manzano Sanz

^*Hospital Universit de Canarias, Anatomía Patológica, La Laguna, Spain

Background & Objective: Sebaceous gland neoplasms (SGN), including sebaceous gland adenomas and carcinomas (SGAs-Cs), are rare skin tumours occurring sporadically or as a phenotypic feature of the Muir-Torre syndrome (MTS). MTS patients tend to have multiple malignancies throughout life (most commonly colorectal carcinomas) and require close surveillance; therefore, differentiation between patients with MTS and sporadic SGN has important implications. Our goal is to evaluate the loss of MMR proteins expression using immunohistochemistry as universal screening in sebaceous neoplasm to distinguish MTS from sporadic SGN.

Method: We retrospectively evaluated MLH1, PMS2, MSH2, MSH6 IHC in all the sebaceous neoplasms diagnosed in our hospital in the period 2012-2017. Eleven were SGAs and five were carcinomas.

Results: Three of the eleven sebaceous adenomas demonstrated loss of expression of a MMR dimer (27%). Two of them showed loss of MSH2-MSH6 (18%) and the other one showed loss of MLH1-PMS2 (9%). Colorectal carcinoma was recently diagnosed in one of the patients, both of neoplasms with MSH2-MSH6 loss of expression. In this case there is a great suspicion of MTS. None of the five SGCs showed loss of expression of MMR proteins.

Conclusion: The percentage of cases with loss of expression is high so universal IHC screening of SGN should be investigated as a first line test to identify MTS and to distinguish from sporadic SGN. It is a cost-effective screening approach, available in most departments.

PS-07-021

A curious cutaneous collision tumour: desmoplastic trichoepithelioma and melanocytic nevus

E. S. Ayva^*, G. Ozgun, N. Ertas

^*Baskent University Medical School, Pathology, Ankara, Turkey

Background & Objective: Collision tumours are defined as neoplasms of two distinct lineages occuring at the same anatomic location. Various combinations of cutaneous collision tumours have been described, most common of these being basal cell carcinoma and melanocytic naevus. Our aim is to report this rare collision tumour –occuring on the face, which was composed of a desmoplastic trichoepithelioma and melanocytic nevus.

Method: A 61-year-old, otherwise asymptomatic woman presented with a lesion located on her right cheek; physical examination revealed a firm, well-defined, skin-colored papule, 1 cm in maximum diameter.

Results: An excisional biopsy was performed for this lesion. Histopathologic examination showed a biphasic tumour composed of narrow strands of diminutive basaloid cells without atypia or mitoses, and interspersed with keratinous cysts, disposed within a desmoplastic stroma, occasional calcifications and ossifications noted. The preceding were intimately mixed with intradermal nests of melanocytes. Immunohistochemically Melan-A positivity was seen in these intradermal naevomelanocytic nests, and melanocytes along the basaloid cell strands. The diagnosis given was - collision tumour with desmoplastic trichoepithelioma and melanocytic nevus components

Conclusion: Cutaneous collision tumours composed of desmoplastic trichoepithelioma and melanocytic naevus are rare. Their pathogenesis is uncertain, though it has been suggested that these synchronous components may be purely coincidental or might afford an example of epithelial induction by melanocytic nevi. Wariness of rare collision tumours, such as this, affords diagnostic accuracy, translating into accurate incidence and possibly unravelment of their pathogenesis.

PS-07-023

Expression of epithelial-to-mesenchimal transition markers in the foreskin of males with lichen sclerosus

S. Lishchuk^*, O. Katunina, A. Sokolova

^*A.I. Burnazyan FMBC, Pathology, Moscow, Russia

Background & Objective: Male genital lichen sclerosus (LS) is a chronic and atrophic mucocutaneous condition with complicated by pathological phimosis, paraphimosis and urethral stricture. Epithelial-to-mesenchimal transition (EMT) could play a role in pathogenesis of this disorder. To study the expression patterns of some markers of the EMT in foreskin from males with LS complicated by scarring phimosis.

Method: The study groups included 10 cases of LS and 10 cases of LS complicated by scarring phimosis. Controls were 10 cases of circumcision in healthy males. IHC was performed with the antibodies to cytokeratin Pan (CK Pan), vimentin and β-catenin.

Results: In healthy foreskin CK Pan and β-catenin expression was noted in keratinocytes of all skin layers. In LS forskin (with and without phimosis) loss of β-catenin expression was seen in basal and parabasal layers. Some CK Pan positive keratinocytes (single and small groups) not connected to epidermis were seen within the upper papillary dermis. Vimentin expression in healthy foreskin was seen in skin dendritic cells. In LS cases foreskin the number of vimentin positive dendritic cells was elevated. In LS cases complicated by the scarring phimosis focal vimentin expression in keratinocytes of basal and parabasal layers was also seen.

Conclusion: Disturbances in the expression patterns of some epithelial and mesenchimal markers in the foreskin with LS are shown. Further studies are needed to determine the role of epithelial-to-mesenchimal transition role in the pathogenesis of male genital LS.

PS-07-024

Trap for pathologists: TRAPP - a case report

Z. Turkmen Usta^*, M. E. Ercin, U. Cobanoglu, S. Ersoz, I. Saygin, E. Turan

^*Karadeniz Technical University, Medical Pathology, Trabzon, Turkey

Background & Objective: Cutaneous pseudolymphomas refer to a group of benign reactive T or B cell lymphoproliferative processes that mimic cutaneous lymphomas. T cell rich angiomatoid polypoid pseudolymphoma (TRAPP) of the skin is a unique form of T cell rich cutaneous pseudolymphoma and only 18 cases described until now in English literature. This entity is recently described and pathogenesis is unknown.

Method: The paraffin-embedded block, H&E, and immunohistochemistry stained sections sent us for consultation with diagnosis as “suspicious for cutaneous lymphoma”.

Results: A 15-year-old girl suffered from a swallowing on her back and the lesion is totally excisioned. The specimen consisted of 0,5cm diameter lesion on the 1,5x1cm dimensions skin. Microscopically polypoid lesion contained thin Grenz zone, hypervascularity under the atrophic epidermis and in the dermis perivascular nodular CD3 predominant lymphocytic infiltration are noticed. Histopathological and immunohistochemical results were compatible TRAPP of skin.

Conclusion: Misdiagnosis of the cases are usual and awareness of the TRAPP is important. Especially epithelioid hemangioma and low-grade cutaneous lymphoma are most frequent concerns but should not fall into the trap of lymphoma and be aware of TRAPP are the main goal of it.

PS-07-025

Can numeric maturation value be used as prognostic indicator and diagnostic tool in cutaneous melanomas (a morphometric study)?

M. Gamsizkan^*, S. Buyucek, S. Kantarcioglu Coskun, M. A. Sungur, E. Ozlu, A. Bahcivan, B. Onal

^*Düzce University, Pathology, Duzce, Turkey

Background & Objective: Some melanocytic lesions can be difficult to diagnose because of ambiguous histological and immunohistochemical features. Morphometric features of melanocytes in the upper and lower parts of the skin may help to differentiate challenging lesions from melanomas.

Method: We studied 28 cases of cutaneous melanomas (CM), 34 cases of dysplastic nevus (DN) and 40 cases of ordinary melanocytic nevus (OMN). All cases were immunostained with Sox-10. The nuclear areas of 30 melanocytes were measured on each upper (U) and deep (D) parts of the skin in all cases by using image J analysis program. Then, a maturation index (U/D) was calculated for each case. Also cutaneous melanomas were categorized into two groups showing pseudomaturation or not.

Results: Mean maturation index was 1.02±0.27 in CM, 1.24±0.29 in DN and 1.59±0.32 in OMN, respectively. There were statistically significant differences between CM - DN (p=0,002) and DN - OMN (p=0,001) for maturation index. According to log-rank test, there was no significant difference between survival distributions of two melanoma groups (p=0.438).

Conclusion: Calculation of maturation index can be used as a supporting tool for the diagnosis of challenging cases.

PS-07-028

Autophagy related LC3A-expressing stone-like structures in keratoacanthoma

S. Arelaki^*, I. Koukourakis, E. Sivridis, K. Balaska, A. Karpouzis

^*AUTH, Dept. of Pathology, Thessaloniki, Greece

Background & Objective: Keratoacanthoma (KA) is a common cutaneous lesion, of unknown etiology. The complexity of the lesion has raised doubts regarding the biologic behavior of the disease. In previous studies we showed that LC3A+ stone like structures (SLS) is a tumour-specific marker for epithelial malignancies. Here we examined the expression of SLS in KA.

Method: We assessed immunohistochemically the expression of LC3A protein in 85 KAs. We also examined the Ki-67 proliferation activity and the nuclear expression of mutant p53 protein.

Results: Forty % the examined cases (34/85) expressed a diffuse cytoplasmic LC3A expression pattern (range from 0-70%, median 0%). The SLS pattern, however, was evident only in 4 of the 85 KAs, (4.7%). The p53 oncoprotein was expressed in 1-90% of cells (median 30%), while the Ki-67 index was expressed in 1-50% of nuclei (median 5%). Neither of these two parameters nor the diffuse cytoplasmic LC3A staining was correlated significantly with the expression of SLSs.

Conclusion: SLSs have been linked with an aggressive tumour behavior. The 4.7% expression of SLSs found in KAs may represent a very small fraction of the disease with aggressive biological behavior. Whether an increased LC3A related autophagic activity is a feature defining malignancy of KAs demands further investigation in cases with clinical progression of the disease.

PS-07-029

YAP nuclear localisation in cutaneous melanoma

S. J. Lee^*, S. K. Kim

^*Severance Hospital, Dept. of Pathology, Seoul, Republic of Korea

Background & Objective: YAP, an effector molecule of Hippo signaling pathway, is expressed at high levels with strong nuclear localization in a number of cancers, including malignant melanoma. In this study, we confirmed a pro-invasive ability of cutaneous melanoma with YAP nuclear expression and analyzed a prognostic role of YAP in cutaneous melanoma that affects metastasis to lymph node and distant organ.

Method: We performed immunohistochemical staining of YAP on formalin-fixed paraffin-embedded (FFPE) tissue.

Results: YAP nuclear localization was identified in 63 cases out of 140 invasive melanomas (45.0%). YAP nuclear localization was more frequent in acral lentiginous and nodular types (P=0.0072) and cutaneous melanomas with YAP nuclear localization demonstrated increased mitotic activity rather than cutaneous melanomas with YAP cytoplasmic localization did (P=0.0490). Cutaneous melanomas with YAP nuclear localization invaded deeper (P<0.0001), more frequently metastasized to the lymph node (P=0.0004), and more frequently metastasized to the distant organs (P<0.0001) than cutaneous melanomas with YAP cytoplasmic localization. In survival analysis, melanoma patients with YAP nuclear localization had poorer disease-free survival (P<0.0001) and overall survival (P=0.0007) using Kaplan-Meier curve. YAP nuclear localization was an independent parameter affecting lymph node metastasis (H.R: 2.270, 95.0% CI: 0.914-5.637, P=0.077) and distant metastasis (H.R: 3.206, 95.0% CI: 1.032-9.961, P=0.044).

Conclusion: Cutaneous melanomas with YAP nuclear localization had histological features of subtype-specificity, increased mitotic activity, and pro-invasiveness with comparison of cutaneous melanomas with YAP cytoplasmic localization. Moreover, YAP localization is expected to be a useful prognostic marker in patients with invasive cutaneous melanoma.

PS-07-030

The histone modification H3K27me3 is reduced in MCPyV-negative Merkel cell carcinomas

M. Matsushita^*, T. Iwasaki, S. Kuwamoto, L. Oka Wardhani, D. Nonaka, K. Nagata, M. Kato, Y. Kitamura, K. Hayashi

^*Tottori University, Yonago, Japan

Background & Objective: Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine skin cancer and 80% cases are associated with Merkel cell polyomavirus (MCPyV). Gene expression and chromatin state are regulated by epigenetic mechanisms including histone modification. Loss of histone modification H3K27me3 has been found in some cancers such as malignant peripheral nerve sheet tumours or paediatric high-grade gliomas. We investigated the association of histone modification H3K27me3 with MCPyV status or prognosis in MCCs.

Method: 42 MCC cases used were 20 MCPyV-positive MCCs, 16 MCPyV-negative cases of combined MCC and squamous cell carcinoma (SqCC) and 6 MCPyV-negative MCCs without combined tumours. FFPE sections of MCCs were immunohistochemically stained with anti-H3K27me3 antibody and evaluated using H-score.

Results: The histone modification H3K27me3 was significantly reduced in MCPyV-negative MCCs than MCPyV-positive ones (p=0.001). In 22 MCPyV-negative MCCs, H3K27me3 was significantly reduced in 16 combined MCC and SqCC cases than 6 pure MCC cases (p=0.027). There was no statistically significant difference between the histone modification H3K27me3 and prognosis.

Conclusion: The differences of the histone modification H3K27me3 among MCPyV-positive MCCS and two MCPyV-negative MCC subtypes suggest that there must be the different mechanisms in carcinogenesis among these three subtypes.

PS-07-032

Relevance of perineural invasion in cutaneous squamous cell carcinoma: prognosis and benefits of radiotherapy

R. A. Posada Caez^*, J. Cañueto, A. Jaka, L. Corchete, A. M. González, R. Garcia, M. J. Fuentes, I. Membrive, A. March, A. Mañes, R. M. Pujol, C. Román-Curto, A. Toll

^*Hospital Germans Trias i Pujol, Anatomical Pathology, Badalona, Spain

Background & Objective: Cutaneous squamous cell carcinoma (CSCC) with perineural invasion (PNI) has a poor prognosis. Postoperatory radiotherapy (PORT) has been commonly implemented in these cases. Nevertheless, the benefit of PORT in the management of CSCC with PNI is still not well-established.

Method: In this retrospective multicenter study we evaluated a cohort of 110 CSCC patients with PNI. Based on PNI caliber, all cases were subdivided into two groups (> 0.1mm and < 0.1mm). PORT efficiency and clinical outcome were determined for each group.

Results: Patients with PNI > 0.1mm showed a clear benefit of PORT, as demonstrated by long-term survival on both univariate analysis and Cox regression models. However, patients in this group showed a persistent risk of poor outcome (5-fold), metastasis, and death (4-fold). On the other hand, patients with PNI <0,1 mm did not show any benefits with PORT.

Conclusion: Our results seem to indicate that CSCC patients with PNI greater than 0.1mm show an improved clinical outcome after PORT. PORT, however, does not show such clear benefits in cases with PNI of small-caliber nerves.

PS-07-033

Clinicopathological features of melanomas in our university and comparison of meta-analysis in a specific region

S. Buyucek^*, M. Gamsizkan, S. Kantarcioglu Coskun, A. Yalcin, E. Karagun, Z. Gamsizkan, B. Onal

^*Duzce University, Pathology, Turkey

Background & Objective: Malignant melanomas are the most common cause of deaths from skin tumours and the incidence is increasing in the world. The studies including descriptive meta-analysis of this tumour in Turkey are limited

Method: Clinicopathological data of melanoma patients between 1998 and 2018 in Düzce were re-evaluated and compared with meta-analysis consisting 7718 cases in the last 32 years of melanomas in Turkey.

Results: In our study, 39 cases were invasive melanoma, 10 cases were in-situ melanoma and 11 cases were extracutaneous melanoma. While 33 (55%) cases were male (M), 27 (45%) cases were female (F); male / femail ratio was 1,22. Mean age was 57,6. Turkey’s male/female ratio was 1,21 and mean age 55,73. The most frequent localization in our series was head and neck; but, lower extremity in Turkey. The most common cutaneous histopathologic subtype was nodular malignant melanoma, followed by superficial spread malignant melanoma, acral lentiginous melanoma and lentigo malign melanoma, respectively. However, superficial spreading malignant melanoma was the most common type in Turkey. In situ melanoma rate was also higher in Düzce compared with Turkey (0,25 vs 0,05).

Conclusion: The industrialization type and sociocultural characteristics of the region may be related to these differences. On the other hand, early detection of the lesions is important for prognosis.

PS-07-034

Histopathological features and Braf status in invasive malignant melanomas: a single center experience of 2 years

D. Nergiz^*, H. Yildirim, D. Süren, Z. Akgündüz, I. Atalay, A. Uslu, A. Alikanoglu, C. Sezer

^*Antalya Research Hospital, Pathology, Turkey

Background & Objective: Invasive malignant melanoma, is an aggressive type of skin cancer and incidence has increased dramatically over the past few decades.

Method: This is a 2 years retrospective analysis. We present our experience with invasive malignant melanoma diagnosed and treated between october 2016- october 2018 in the Department of Pathology of University of Health Sciences, Antalya Training and Research Hospital, Antalya, Turkey. Incisionel biopsies and external center consultations were not included in the study.

Results: This study involved a total of 37 cases. The median age of affected patients was 62,8 (range: 33- 81 years). The female to male ratio was 1.3/1. Revised and re-confirmed 37 cases of the diagnosis, 28 cases were cutaneous, 8 cases were located in anogenital mucosa and 1 case was located in meninges. The most common subtype was nodular melanoma. The most common site is upper extremite and head and neck. The median tumour size of cutaneous tumours was 16,4 mm (range: 3- 40 mm). The median maximum tumour thickness (Breslow) was 4,2 mm (range: 0,2- 16 mm). The most common anatomic (Clark) level was 4 (range: 1- 5). 10 of 28 cases analyzed of BRAF V600 mutations and 4 of 10 ( 40%) case were positive. All of anogenital mucosal cases and menengial case were negative for PCR-based analyzed of BRAF V600 mutations.

Conclusion: The levels of both melanoma incidence and mortality vary considerably worldwide. The diagnosis of melanoma is based on histopathological examination and immunohistochemical stains, but BRAF mutation analyses is critical to the treatment decision.

PS-07-035

A completely regressed melanoma firstly diagnosed by its abdominal wall metastasis: a case study

D. Koumoundourou^*, C. Oikonomou, P. Ravazoula

^*University Hospital of Patras, Greece

Background & Objective: Complete regression of melanomas is rare and may be correlated with tumours of indeterminate derivation. We describe a case of a metastatic nodule microscopically diagnosed as metastatic melanoma. The primary site was a totally regressed melanocytic lesion in the upper limb.

Method: A 49-years old patient conferred to our hospital because of the presence of a mass of the abdominal wall, 4cm in greatest diameter that was surgically treated. On gross examination the mass was partially-encapsulated, gray-coloured with a fleshy consistency.

Results: Histologic examination revealed a malignant neoplasm comprising of nests of large epithelioid tumour cells with pleomorphic, hyperchromatic nuclei, nucleoli and eosinophilic cytoplasm that were S-100, Melan-A, HMB-45 and MITF positive and negative for epithelial markers. The diagnosis was compatible either with metastatic malignant melanoma or with a clear cell sarcoma. The patient was intimately searched for a melanoma primary and a low back skin lesion was also sent for pathologic evaluation and was compatible with complete regression of melanoma

Conclusion: By the absence of any other primary, the diagnosis of a completely regressed melanoma was made. Although partial regression occurs in 10-35% of melanomas, only 34 cases of totally regressed melanomas have been referred in the literature. The exact mechanism of regression remains to be elucidated however any patient with a metastatic melanoma needs a thorough cutaneous examination.

PS-07-036

Linear sclerodemic lupus erythematosus - a rare variant of linear morphea and discoid lupus erythematosus

D. Sakiz^*, B. Erdogan, B. Gedik, H. Sönmezer

^*SBU Bakirkoy Dr Sadi Konuk ERH, Pathology, Istanbul, Turkey

Background & Objective: Linear morphea “en coup de sabre” is a localized form of morphea that represents paramedian face and/or frontal scalp depression concomitant occurence of discoid lupus erytematosus (DLE) and morphea in the same skin lesion is exceptional and has only been reported in lesion less then five patients. This condition has been named “sclerodermiform linear lupus erythematosus” by some authors.

Method: A 25-year-old women, presented with a sclerotic plaque and alopecia with erythematous halo of the forehead over one year. Physical examination was normal. Antinuclear antibodies and anti-ENA antibodies were normal at laboratory examination.

Results: Microscopic findings of two skin biopsiy speciemens from lesion showed hyperkeratosis, atrophy in the epidermis, vacuolation of epidermal basal cell layer and perivascular, periadnexial inflamatory infiltrates in the papillary and reticular dermis. In adition there was hyalinization of the collagen bundles in the reticular dermis. Increased dermal mucin, thickening basal membrane at the epidermis and hair follicular epithelium were observed with periodic acid-Schiff stain.

Conclusion: Overlap syndrome are defined as a disorder that statisfy diagnostic criteria of two or more different connective tissue disease concurently or consecutively. Rarely the overlap occurs at the same tissue site. Our case demonstrates lupus erythematosus and morphea in the same lesion.

PS-07-038

Dermatomyositis as a paraneoplastic syndrome

C. González Núñez^*, M. Narváez Simón, A. González Fábrega, B. Rueda Villafranca, J. Aneiros Fernández, C. L. Ramírez Tortosa

^*Complejo Hospitalario Granada, Surgical Pathology, Spain

Background & Objective: Dermatomyositis (DM) is an uncommon autoimmune disorder characterized by inflammatory muscular and cutaneous disease, its etiology remains yet unknown. Its paraneoplastic character has been demonstrated in up to 20-30% cases in adults, where this entity could reveal primitive malignancy or metastatic relapse. We report a case of a female firstly diagnosed with DM in which there was eventually found a breast invasive ductal carcinoma grade-II. Dermatomyositis may represent a paraneoplastic syndrome of many neoplasms, as breast carcinoma.

Method: We report a case of a 67-year-old female patient with an extensive violaceous rash and progressive proximal muscle weakness resistant to medical treatment. A 4mm skin punch biopsy was performed.

Results: Histological findings: epidermal atrophy, loss of rete ridges, decreased granule cell layer, scattered apoptotic keratinocytes and pigment incontinence. Interface dermatitis with basal vacuolar degeneration. Sparse superficial perivascular lymphoplasmacytic infiltrate associated with intense edema with increased dermal mucin in the upper dermis highlighted by Alcian Blue. Absence of signs of vasculitis. Diagnosis of dermatomyositis was made and its potential paraneoplastic origin was suggested. After a week, the patient was diagnosed with breast invasive ductal carcinoma (G-II).

Conclusion: Dermatomyositis is an idiopathic inflammatory myopathy which affects skeletal muscle and skin. Malignancy should be taken into consideration when a patient is newly diagnosed with DM. In order to do a correct differential diagnosis, a proper clinical correlation is needed to avoid diagnostic pitfalls as the histological findings may resemble other entities, as usual dermatomyositis or acute lupus. With every new diagnosis of DM, malignancy should always be excluded.

PS-07-039

Pigmented epithelioid melanocytoma: a rare borderline melanocytic lesion

M. Ozgur Gunay^*, M. Cavus Ozkan, L. Cinel

^*Marmara University Hospital, Pathology, Istanbul, Turkey

Background & Objective: Pigmented epithelioid melanocytoma (PEM) is a recently proposed term that was previously known as “animal type melanoma”. The purpose of this case report is to present a young female with pigmented lesion diagnosed as PEM.

Method: A 17-year-old woman presented with a 0.7x0.7 cm black nodular lesion on the right knee since her childhood. Medical history of the patient revealed no spesific features. There was no personal or family history of skin cancer. A complete excision was performed.

Results: Histopathologically, the lesion was characterized by heavily pigmented epithelioid cells with prominent nucleoli and interspersed melanophages in the dermis and subcutaneous tissue. Mitosis and necrosis were not observed. The depth of invasion was classified as Clark level IV, with maximum thickness of 2,5 mm. The lesion was diagnosed as PEM on final histopathology report.

Conclusion: PEM is a very rare, borderline melanocytic lesion and has regional lymph node metastasis potential. Clinically, PEM occurs any age, but usually children and young adults. PEM is histologically similar to “epithelioid blue nevus” and differantial diagnosis with other pigmented lesions such as heavily pigmented melanoma, regressing melanoma, blue nevus, recurrent nevus, combined nevus, deep penetrating nevus and spitzoid tumour can be difficult.

PS-07-041

The expressions of IDO1/TDO2 in tumour cells and tumour microenvironment are associated with MCPyV status and prognosis in Merkel cell carcinomas

L. O. Wardhani^*, M. Matsushita, T. Iwasaki, S. Kuwamoto, D. Nonaka, K. Nagata, M. Kato, Y. Kitamura, K. Hayashi

^*Tottori University, Molecular Pathology Division, Yonago, Japan

Background & Objective: Merkel cell carcinoma (MCC) is known as a rare yet aggressive cutaneous cancer with neuroendocrine features and it is related to Merkel cell polyomavirus (MCPyV) in about 80% of cases. Indoleamine 2, 3-dioxygenase 1 (IDO1) and tryptophan 2, 3-dioxygenase 2 (TDO2), the key and rate-limiting enzymes of the tryptophan to kynurenine metabolic pathway, play a role in several cancer types as part of avoiding immunosurveillance process. We investigated the association of IDO1/TDO2 expression with MCPyV status and prognosis in MCCs.

Method: 24 MCPyV-positive MCCs, 13 MCPyV-negative MCCs combined with squamous cell carcinoma (SqCC), and 7 MCPyV-negative pure MCCs were used. FFPE sections were stained immunohistochemically with IDO1 and TDO2 antibodies and examined using H-score.

Results: IDO1 expression in MCC tumour cells was higher significantly in MCPyV-negative MCCs than in MCPyV-positive ones (p<0.001). In 13 MCCs combined with SqCC, tumour cells also highly expressed IDO1 in MCCs rather than in SqCCs (p<0.001). There was no different TDO2 expression of tumour cells between MCPyV-positive and -negative MCCs. The tumour microenvironment (TME) in MCPyV-negative MCCs expressed TDO2 more frequently than in MCPyV-positive ones (p<0.001). MCCs with lower IDO1 expression in tumour cells and MCCs with lower TDO2 expression in TME had better prognosis than otherwise (p=0.043, p=0.008, respectively).

Conclusion: The different expressions of IDO1 in MCC tumour cells or TDO2 in TME between MCPyV-positive and -negative MCCs suggest that IDO1 or TDO2 plays a role differently in tumourigenesis mechanism and biology of MCPyV-positive and -negative MCCs.

PS-07-042

Interstitial mycosis fungoides: a rare variant

M. Gamsizkan^*, A. Bahcivan, E. Ozlu, E. Karagun, Y. Ozcan, A. Yalcin

^*Düzce University, Pathology, Duzce, Turkey

Background & Objective: Mycosis Fungoides (MF) is the most common form of primary cutaneous lymphoma that presents a wide clinicopathologic spectrum. Histologically, MF generally displays superficial perivascular or band-like lymphocytic infiltrate with epidermotrophism. Infrequently it can show different patterns such as interstitial, lichenoid, spongiotic, syringotropic or granulomatous etc. Interstitial MF is a quite rare form of MF with an interstitial dermal infiltrate mimicking interstitial granuloma annulare, inflammatory morphea and interstitial granulomatous dermatitis. There are few reports and small series regarding with interstitial MF in the literature.

Method: A 38 years old male patient presented with a three years history of slightly erytematous scaly patchy lesions on his trunk and upper extremities. Preliminary diagnoses were MF and morphea.

Results: The first biopsy didn’t show an epidermotrophic infiltration. Therefore, we couldn’t exclude the diagnoses of early morphea or interstitial MF and suggested follow up with biopsies repeatedly. After two months follow-up the second biopsy revealed epidermotrophism beside the dermal periadnexial interstitial inflammatory infiltrate with predominance of atypical cerebriform lymphocytes. The neoplastic cells showed immunopositivity for CD3 and CD8. Additionally, there was focally absence of CD7 in the infiltrate.

Conclusion: We reported this case as interstitial MF and discussed with the literature.

PS-07-043

Atypical fibroxanthoma arising on chronic burn scar: a rare case report and the review of the literature

E. Calis^*, M. Keskin, A. Cakir, I. Turkmen

^*Medipol University, Pathology, Istanbul, Turkey

Background & Objective: Atypical fibroxanthoma (AFX) is a low-grade sarcoma, characterized by a population of spindle, epithelioid and pleomorphic cells, mostly on a background of actinic damage in elderly patients. But uncommonly it can develop on a burn scar with or without actinic damage.

Method: A 31-year-old male patient with a history of a thermal burn 20 years ago, admitted to plastic surgery service with the complaint of intractable ulcer despite conservative treatment for 6 months on his mid-back. A solitary, firm, well-demarcated nodule was noted just lateral to the left mid-back, measuring 2x2 cm in size. The surrounding skin showed mild contracture. Wide excision was performed with a clinical diagnosis of Marjolin’s ulcer.

Results: Tumour was composed of pleomorphic spindle cells, admixed with multinucleated osteoclast-like giant cells and mononuclear inflammatory cells. Mitotic activity is brisk, including numerous atypical and bizarre forms. There was no epidermal connection or precursor lesion in the epidermis. The overlying epidermis was atrophic. There was neither necrosis nor vascular, lymphatic or perineural invasion. The immunohistochemical staining revealed strong positivity for CD68 and CD10. Neoplastic cells were negative with cytokeratin, p40, p63, HMB45, smooth muscle actin and CD34. Ki67 proliferation index was low (7-8 %). On the basis of the burn scar history, clinical and pathological findings, a final diagnosis of AFX was given.

Conclusion: Herein, we present a rare case of AFX arising on the non sun-exposed area within a chronic burn scar of a young patient.

PS-07-044

Penile intraepithelial neoplasia: case report and review of literature

F. Gargouri^*, R. Ayadi, I. Msakni, N. Mansouri, R. Yaïche, S. Baker, M. Raboudi, B. Laabidi

^*Hôpital Militaire de Tunis, ANAPATH, Tunisia

Background & Objective: Penile intraepithelial neoplasia (PeIN) is a rare disease that can be associated with great morbidity and mortality. The risk of progression from PIN to invasive carcinoma is estimated to be between 10% and 30%. Treatment options include topical chemotherapy, immunotherapy, laser treatment, photodynamic therapy and surgical excision. Our aim was to evaluate the outcome of both cryotherapy and imiquimod to treat PeIN

Method: A 24-year-old presented with lesion at the meatus on the glans penis of 4 months duration for which he had not previously sought medical attention. He had at the beginning a surgical excision.

Results: Histologic results showed epidermal acanthosis, prominent atypical parakeratosis. The epithelium is replaced by a monotonus population of small to intermediate sized cells. In the uppers layers of the epidermis presence of numerous koilocytes who have vacuolated scant basophilic cytoplasm and indistinct cell borders with shrunked nuclei. There was no evidence of an invasive component. Immunohistochemical (IHC) studies showed positive staining of these cells for p16. Ki67 proliferation index was 90%. Based on these histologic and IHC findings, the final diagnosis of PeIN was established. The limits of excision cannot be evaluated. The postoperative course is marked by a recurrence of the lesion. The patient then benefited from a treatment by cryotherapy and imiquimod with a good evolution and complete disappearance of the lesion.

Conclusion: Given the favorable response and purported benefits of combination therapy, we propose the use of cryotherapy with topical imiquimod in the treatment of PeIN.

Monday, 10 September 2018, 09:30 - 10:30, Exhibition Hall I/II

PS-08 | Haematopathology

PS-08-001

Mixed histiocytosis (Langerhans cell histiocytosis and Erdheim-Chester disease) with vascular involvement: a rare cause of refractory systemic arterial hypertension

I. Gullo^*, P. Marques, J. M. Lopes

^*Centro Hospitalar São João, Pathology Dept., Porto, Portugal

Background & Objective: The co-occurrence of Langerhans cell histiocytosis (LCH) and Erdheim-Chester disease (ECD) is rare. Aim: to report a systemic mixed LCH/ECD with vascular involvement and systemic arterial hypertension (SAH).

Method: A 63-year-old-woman was referred due to refractory SAH, despite treatment with several antihypertensive drugs, diagnosed three years before. The previous relevant medical history was diabetes insipidus, diagnosed at 34y, and LCH of skin/bone/liver at 50y. She was treated with cytarabine for one year.

Results: The patient had no other relevant risk factors for cardiovascular events (e.g. hyperlipidaemia, diabetes mellitus and smoking). Screening for renovascular disease revealed bilateral stenosis of renal arteries, atrophy of the right kidney, and secondary hyperaldosteronism. Angioplasty/stenting of the left renal artery was performed, allowing blood-pressure control (115/66mmHg). Fourteen days later, she was admitted for acute mesenteric ischemia due to stenosis of the superior mesenteric artery, submitted to angioplasty/stenting. To clarify the pathogenesis of the aforementioned vascular stenoses, we re-evaluated the pathological features of previous bone (a) and liver (b) biopsies that revealed: (a) expression of S100+/CD1a+ in bona-fide Langerhans cells, with eosinophils, and sheets of S100-/CD1a- foamy histiocytes, with Touton giant cells, consistent with a mixed LCH/ECD; (b) LCH associated with secondary sclerosing cholangitis.

Conclusion: ECD can be an under-diagnosed cause of multiple arterial stenoses and SAH, but they occur in ~70% and ~20% of ECD reported cases, respectively. So far, 40 cases of mixed LCH/ECD have been reported, but without mention to refractory SAH, as described in the present case, with impact in patients’ management.

PS-08-003

Immunohistochemical and ultrastructural analysis of an ALK-positive anaplastic large cell lymphoma presenting with systemic capillary leak syndrome

A.-C. Lisievici^*, T.-A. Georgescu, N. Petre, S. A. Barbu, I. A. Ganta, F. Pop

^*Emergency University Hospital, Bucharest, Romania

Background & Objective: ALK-positive anaplastic large cell lymphoma (ALCL) was initially described in 1982 by Stein and his collaborators as an aggressive T-cell lymphoma with higher incidence in young males and better prognosis that other T-cell lymphomas. It is usually associated with t(2;5)(p23;q35), which gives rise to the NPM-ALK fusion protein.

Method: We report the case of a 38-year-old male presenting to our clinic with uncontrolled anasarca through systemic capillary leak syndrome. The patient was allergic to plasma solutions. Blood tests revealed leukocytosis with neutrophilia and hypoalbuminemia. A thorough ultrasound examination revealed hepatosplenomegaly and enlarged inguinal and supraclavicular lymph nodes. The patient underwent surgical excision of the inguinal lymphadenopathy. Frozen sections revealed a high-grade neoplastic proliferation, which could not exclude the diagnosis of large cell lymphoma.

Results: Histological examination revealed a neoplastic proliferation of discohesive large anaplastic cells, with eosinophilic cytoplasm, round or horseshoe nuclei and high mitotic rate (16 mitoses/10 HPF). Immunohistochemically, the cells were completely negative for AE1/AE3, PAX5, CD5, CD20 and diffusely positive for EMA, CD30 and ALK, the latter having both nuclear and cytoplasmic immunoreactivity. This pattern of staining for ALK is suggestive for the presence of t(2;5)(p23;q35). Electron microscopy revealed enlarged horseshoe nuclei with dispersed chromatin and convoluted contours, some organelles and cytoplasmic cytotoxic granules. The patient died 2 weeks after diagnosis.

Conclusion: Although ALK-positive ALCL usually has a good prognosis, cases with aggressive evolution have been reported in young patients. Prognosis may be correlated with the presence of intracytoplasmic cytotoxic granules, which could be responsible for systemic capillary leak syndrome

PS-08-004

The impact of micro vessel density on patient survival with diffuse large B-cell lymphoma

A. Birceanu Corobea^*, A. Evsei, A. Dumitru, M. Gheorghe, M. Sajin, N. Copca, G. Birceanu

^*Clinical Hospital Saint Mary, Pathology, Bucharest, Romania

Background & Objective: Diffuse large B cell lymphoma is a clinically morphological and molecular heterogeneous disease. Angiogenesis-related signature and gene expression profile were shown to affect patient survival and unfavorable prognostic. The purpose of this study is to assess the prognostic impact of micro vessel density in one series of patients with diffuse large B cell lymphoma.

Method: Eighty patients with diffuse large B cell lymphoma from the Haematology Department of the Coltea Clinical Hospital were included in the study and underwent combined rituximab–R-CHOP treatment. Microvessels were immunostained with CD 34 and VEGFR and quantified manually.

Results: Correlation between VEGFR intensity and CD 34 intensity in diffuse large B cell lymphoma was statistically significant. The patients who presented intensity positivity for VEGFR have shown strong correlation with a highly positivity CD 34 vascularization. The germinal center B cell -like (CGB) type was associated with a low microvessel density and VEGFR negativity and the non-germinal center B – cell like (non- CGB) type was associated with a high microvessel density and an intense positivity for VEGFR. The patients with a low microvessel density (CD 34 positive) and VEGFR negativity correlates with a poor treatment response and also with relapse. The survival rates decrease proportionally with the microvessel density.

Conclusion: These findings highlight the impact of angiogenesis in the outcome of patients with diffuse large B cell lymphoma and may represent an exciting new interest regarding antiangiogenic drugs in clinical trials.

PS-08-006

CD4 positive indolent T-cell lymphoproliferative disorder of the gastrointestinal tract with high proliferative index: a case report and literatures review

Y. Fu^*, Q. Shi, J. Chen, X. Fan

^*Drum Tower Hospital, Dept. of Pathology, Nanjing, People's Republic of China

Background & Objective: Indolent T cell lymphoproliferative disorder of the gastrointestinal tract is a clonal T cell lymphoproliferative disorder that can involve the mucosa in all sites of the gastrointestinal tract. Despite the indolent clinical course, most patients do not respond to conventional chemotherapy.

Method: We report a case of CD4+ indolent T cell lymphoproliferative disorder of the gastrointestinal tract involving ileum and oropharynx, and review literatures of all cases of CD4+ indolent T cell lymphoproliferative disorder of the gastrointestinal tract reported to date.

Results: CD4+ indolent T cell lymphoproliferative disorder of the gastrointestinal tract may have malignant potential.

Conclusion: It is necessary to combine imaging, clinical symptoms and pathological diagnosis. Generally, Ki-67 index of this lesion is very low and often less than 10% but may increase to 20% occasionally.

PS-08-007

Primary T-cell lymphoblastic lymphoma of the ovary: insights into a rare case report and systematic literature review

M. L. Marques Piubelli^*, G. de Sanctis Callegari, S. A. Coelho Siqueira

^*Universidade de São Paulo, Anatomic Pathology Dept., Brazil

Background & Objective: Primary ovarian non-Hodgkin lymphomas are defined by Fox criteria and account for 1.5% of all ovarian neoplasms, with primary T-cell lymphoblastic lymphoma of the ovary an extreme rare entity.

Method: A 29-year-old woman with a medical history of Thymoma treated 7 years ago, develops symptoms of increased abdominopelvic volume and irregular menstrual cycle. An abdominal positron emission tomography (PET-CT) was performed and showed bilateral, solid, expansive ovarian lesions, measuring 10 cm to the right and 10.5 cm to the left, without associated lymphadenopathy. Diagnostic left salpingo-oophorectomy under microscopy, demonstrated uniform lymphoid proliferation of intermediate-sized cells, with scant cytoplasm, dispersed chromatin and poorly evident nucleoli. Immunophenotypically was strongly and diffuse positive for CD3, CD10, CD99 and TdT, focal positive for BCL-2, negative for CD20 and with high Ki-67 index. Bone marrow biopsy did not show involvement due to lymphoma. The patient had complete remission of the disease after treatment with BFM 86 protocol.

Results: In a systematic review, only 2 other cases of primary T-LBL of the ovary were found in the English-language literature. Both represented young women as abdominal and/or pelvic pain, as the case reported. Regarding the laterality of the lesion, one case affected both ovaries and another only the right ovary. They also had the same histopathological and immunophenotypic characteristics, being positive for CD3, CD10, TdT and CD99, as in the presented case. Chemotherapy was used as treatment in both, but only 1 with remission.

Conclusion: The few cases of primary T-LBL of the ovary, sharing clinicopathological and phenotypic characteristics.

PS-08-008

Concomitant Erdheim-Chester disease and acute myeloid leukemia: clinical and molecular characteristics of a rare association

C.-Y. Tsai^*, I. Letovanec, J.-L. Barras, E. Missiaglia, J. Pouw Schoumans, A. Van der Gucht, O. Spertini, B. Bisisg, L. de Leval

^*CHUV, Pathology, Lausanne, Switzerland

Background & Objective: Erdheim-Chester disease (ECD) is a rare form of histiocytosis frequently associated with mutations of BRAF or other MAPK pathway genes. Recent works have provided evidence of a haematopoietic stem cell origin of some systemic histiocytoses. These discoveries have raised the question of a possible association or even an etiologic relationship between ECD or LCH and myeloid neoplasms. Herein, we report the case of a 71-year-old man with concomitantly diagnosed ECD and acute myelomonocytic leukemia (AMML).

Method: The patient was admitted for cardiac decompensation and imaging studies showed pleural effusion, bilateral perirenal fat infiltration, and symmetrical involvement of proximal long bones. He also developed increasing leucocytosis. Bone marrow biopsy and aspirate showed images qualifying for a diagnosis of AMML.

Results: Perirenal and pleural biopsies revealed infiltration by CD163+, CD68+/-, S100+/-, CD1a- and Langerin-negative histiocytes, some with foamy cytoplasm, prompting a diagnosis of ECD with multisystemic involvement. NGS studies using a myeloid panel in both pleural and bone marrow biopsies revealed a complex profile encompassing NRAS, SRSF2, TET2 and TP53 mutations in addition to BRAFV600E mutation in both specimens.

Conclusion: While most myeloid neoplasms reported so far in ECD patients consist of myeloproliferative neopalsms or myelodysplastic syndromes, co-occurrence of an acute myeloid leukemia is exceptional. Our case is remarkable by the common complex mutational landscape in both ECD and AML. These observations raise the possibility that, in our case, ECD and the myeloid neoplasm may not only share a common cell of origin but also result from linear evolution along the same molecular oncogenic pathway.

PS-08-010

CD23 expression in follicular lymphoma: the IgD clue

C. Mestre Alagarda^*, C. Martínez-Ciarpaglini, C. Fernández Sellers, L. Alarcón Molero, A. Moscardó Navarro, C. Alfaro-Cervelló, J. Aliaga Patiño, D. Mata, I. Pastor, D. Morello González, A. Teruel, A. Ferrández

^*Hospital Clinico Universitario, Servicio Anatomía Patológica, Valencia, Spain

Background & Objective: CD23 defines a recently recognized subtype of follicular lymphomas (FLs) with diffuse pattern and little tendency to disseminate. However, some cases with follicular pattern are positive for CD23 and the influence of CD23 expression in the clinical outcome is controversial. We aimed to assess the expression of CD23 in neoplastic cells and in mantle cells, defined by IgD positivity, in cases with follicular and diffuse morphology and to investigate its possible association with the disease-free survival (DFS) probability.

Method: We retrospectively evaluated 111 biopsy specimens diagnosed as FLs, for growth pattern and grade. The immunohistochemical pattern of expression of CD23 and IgD was recorded.

Results: 79% of cases showed follicular pattern and 21% presented a diffuse component in variably proportion. CD23 expression in lymphoid cells was observed in 76 cases (69%) and, in 51 of these cases (68%), positive cells were classified as mantle cells, since they showed IgD coexpression and a predominant mantle-like distribution. These mantle cells were significantly more frequent in cases with follicular pattern (p=0,01, X2). Once excluded the mantle cells component, a better DFS probability was observed in diffuse FLs positive for CD23 in neoplastic cells, but not in cases with follicular pattern (p=0,07, Long-Rank). Further analyses with more cases are needed to improve the statistical significance of this result.

Conclusion: Most CD23 positive cells observed in FLs are actually mantle cells, being more frequent in cases with follicular than diffuse pattern. CD23 positivity in cases with at least partial diffuse component seems to correlate with a longer DFS.

PS-08-011

Clonality assessment of disseminated MALT lymphoma

D. Fernández Calvo^*, M. Condom Esteve, E. Domingo-Domènech, M. Pané Foix, M. Varela Rodríguez, C. Chappuis de Oliveira, J. Hernández Gañán, S. Mercadal, E. González Barca, I. Carro, M. Oliva, C. Aguilera, A. Sureda, J. Azcarate Rodríguez, L. Riasol Rodes, E. Dorca Duch, J. Bosch Schips, N. Espejo Herrera, F. Climent Esteller

^*Hosp. Universitari Bellvitge, Pathology, Barcelona, Spain

Background & Objective: Extranodal mucosa-associated lymphoid tissue (MALT) lymphomas account for 7-8% of all non-Hodgkin lymphomas, being the stomach the most frequent location. It is a disseminated disease in approximately 50%of extragastric MALT lymphomas, and 25% of gastric ones. There is very little literature published about the clonal relationship of MALT lymphomas with disseminated involvement. To study clonality of our disseminated MALT lymphomas.

Method: We reviewed all the cases of MALT lymphoma diagnosed in a single centre between 2009 and 2017. Cases that affected multiple locations were selected, both multifocal and multiorgan, excluding those with exclusive skin involvement. Clonality was detected by PCR for IGH (FR3 and FR2), and for IGK.

Results: Our series comprise 80 patients. Disseminated disease was present in 27 (34%) patients, 13 males and 14 females with a median age of 60 years (range: 38-84). Of those, one (4%) patient had multifocal MALT; 22 (81%) patients had multiorgan MALT; and 4 (15%) patients had both. The most frequently involved primary locations were salivary gland (18.5%) and lymph nodes (15%). All patients received treatment: 23 (85%) patients received chemotherapy, 2 (7%) radiotherapy, 1 (4%) surgery, and 1 (4%) chemotherapy plus surgery. Clonality was analyzed in 52 samples from 24 different patients. We could compare 16 patients. In 6 o