Abstract
The large majority of gastrointestinal stromal tumors (GIST) can be diagnosed on the basis of KIT immunoreactivity. However, some atypical tumors show weak or negative KIT expression. We studied the imaging characteristics of atypical GIST, reviewing CT and MRI findings in ten patients (eight men, two women; mean age 59 years) with atypical GIST. Radiological studies were evaluated by two radiologists by consensus and included CT and MR imaging in all patients. Pathological diagnoses were made from surgery and confirmed by the polymerase-chain reaction (PCR) to amplify both exons of the c-kit gene and PDGFRA gene. The CT and MR examinations revealed a heterogeneous mass of the stomach containing cystic regions and soft tissue elements in all cases. All lesions were extraluminal masses and had an exophytic epicenter. On T1-weighted MR images soft tissue elements of the tumors were of homogeneously low- (n=3) or iso-signal intensity (n=7) compared with the liver parenchyma. On fast spin-echo T2-weighted MR images soft tissue elements of all tumors showed cystic regions of significantly high signal intensity interspersed with septumlike structures of low signal intensity. All lesions exhibited homogeneously (n=4) or heterogeneously (n=6) mild to moderate enhancement of soft tissue elements. Despite the relatively small number of patients CT and MRI findings of atypical GIST are a submucosal mass with soft tissue elements and cystic regions.
Similar content being viewed by others
References
Miettinen M, Lasota J (2001) Gastrointestinal stromal tumors—definition, clinical, histological, immunohistochemical and molecular genetic features and differential diagnosis. Virchows Arch 438:1–12
Rossi C, Mocellin S, Mencarelli R et al (2003) Gastrointestinal stromal tumors: from a surgical to a molecular approach. Int J Cancer 107:171–176
Nishida T, Hirota S (2001) Biological and clinical review of stromal tumors in the gastrointestinal tract. Histol Histopathol 15:1293–1301
Singer S, Rubin BP, Lux ML et al (2002) Prognostic value of KIT mutation type, mitotic activity, and histologic subtype in gastrointestinal stromal tumors. J Clin Oncol 20:3898–3905
Heinrich MC, Corless CL, Demetri GD et al (2003) Kinase mutations and imatinib response in patients with metastaticgastrointestinal stromal tumor. J Clin Oncol 21:4342–4349
Sandrasegaran K, Rajesh A, Rushing DA et al (2005) Gastrointenstinal stromal tumors: CT and MRI findings. Eur Radiol 15:1407–1414
Ghanem N, Altehoefer C, Furtwangler A et al (2003) Computed tomography in gastrointestinal stromal tumors. Eur Radiol 13:1669–1678
Horton KM, Juluru K, Montogomery E et al (2004) Computed tomography imaging of gastrointestinal stromal tumors with pathology correlation. J Comput Assist Tomogr 28:811–817
Kim HC, Lee JM, Kim SH et al (2005) Small gastrointestinal stromal tumours with focal areas of low attenuation on CT: pathological correlation. Clin Radiol 60:384–388
Takao H, Yamahira K, Doi I et al (2004) Gastrointestinal stromal tumor of the retroperitoneum: CT and MR findings. Eur Radiol 14:1926–1929
Buckley JA, Fishman EK (1998) CT evaluation of small bowel neoplasms: spectrum of disease. Radiographics 18:379–392
Subramanian S, West RB, Corless CL et al (2004) Gastrointestinal stromal tumors (GISTs) with KIT and PDGFRA mutations have distinct gene expression profiles. Oncogene 23:7780–7790
Debiec-Rychter M, Wasag B, Stul M et al (2004) Gastrointestinal stromal tumours (GISTs) negative for KIT (CD117 antigen) immunoreactivity. J Pathol 202:430–438
Medeiros F, Corless CL, Duensing A et al (2004) KIT-negative gastrointestinal stromal tumors: proof of concept and therapeutic implications. Am J Surg Pathol 28:889–894
Wasag B, Debiec-Rychter M, Pauwels P et al (2004) Differential expression of KIT/PDGFRA mutant isoforms in epithelioid and mixed variants of gastrointestinal stromal tumors depends predominantly on the tumor site. Mod Pathol 17:889–894
Sakurai S, Hasegawa T, Sakuma Y et al (2004) Myxoid epithelioid gastrointestinal stromal tumor (GIST) with mast cell infiltrations: a subtype of GIST with mutations of platelet-derived growth factor receptor alpha gene. Hum Pathol 35:1223–1230
Hirota S, Ohashi A, Nishida T et al (2003) Gain-of-function mutations of platelet-derived growth factor receptor alpha gene in gastrointestinal stromal tumors. Gastroenterology 125:660–667
Hasegawa T, Matsuno Y, Shimoda T et al (2002) Gastrointestinal stromal tumor: consistent CD117 immunostaining for diagnosis, and prognostic classification based on tumor size and MIB-1 grade. Hum Pathol 33:669–676
Yamaguchi U, Hasegawa T, Matsuda T et al (2004) Differential diagnosis of gastrointestinal stromal tumor and other spindle cell tumors in the gastrointestinal tract based on immunohistochemical analysis. Virchows Arch 445:142–150
Trupiano JKR, Stewart RE, Misick C et al (2002) Gastric stromal tumors: a clinicopathologic study of 77 cases with correlation of features with nonaggressive and aggressive clinical behaviors. Am J Surg Pathol 26:705–714
Antoch G, Kanja J, Bauer S et al (2004) Comparison of PET, CT, and dual-modality PET/CT imaging for monitoring of imatinib (STI571) therapy in patients with gastrointestinal stromal tumors. J Nucl Med 45:357–365
Choi H, Charnsangavej C, de Castro Faria S et al (2004) CT evaluation of the response of gastrointestinal stromal tumors after imatinib mesylate treatment: a quantitative analysis correlated with FDG PET findings. AJR Am J Roentgenol 183:1619–1628
Busalacchi PJ Sr, de la Calle MA, Torroba A et al (2005) Gastrointestinal stromal tumor with metastases in an adult woman treated with imatinib mesylate: MDCT findings. AJR Am J Roentgenol 184:S58–S61
Acknowledgements
This work was supported in part by grants for Scientific Research Expenses for Health and Welfare Programs, No. 17‐12 and BMS Freedom to Discovery Grant.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Tateishi, U., Miyake, M., Maeda, T. et al. CT and MRI findings in KIT-weak or KIT-negative atypical gastrointestinal stromal tumors. Eur Radiol 16, 1537–1543 (2006). https://doi.org/10.1007/s00330-005-0091-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00330-005-0091-3