Clinicopathological Meaning of Size of Main-Duct Dilatation in Intraductal Papillary Mucinous Neoplasm of Pancreas: Proposal of a Simplified Morphological Classification Based on the Investigation on the Size of Main Pancreatic Duct
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The 2012 consensus guideline on intraductal papillary mucinous neoplasm of the pancreas (IPMN) described a three-stage criteria involving main pancreatic duct (MPD) size with definitions of malignancy relevant for treatment decisions. Re-evaluation and simplification of this classification for clinicians are warranted.
Data from the Seoul National University Hospital of 375 consecutive patients with pathology-confirmed IPMN after surgery were analyzed. The association between clinicopathologic characteristics of IPMN and MPD size was assessed. The cut-off value of MPD size for a current definition of malignancy prediction was calculated.
Diagnostic accuracy for malignancy was highest when the cut-off value of MPD size was 7 mm (area under the curve = 0.7126). Dichotomizing IPMN into MPD ≤7 mm versus MPD >7 mm, patient age (p = 0.039), sex (p = 0.001), presence of mural nodule (p < 0.001), and invasiveness risk (13.2 vs. 39.8 %, p < 0.001) resulted in significantly different results. Mural nodule-negative patients with MPD >7 mm had a significantly lower 5-year survival rate than those with MPD ≤7 mm (78.4 vs. 91.4 %, p = 0.006). Among patients with MPD size ≤7 mm, elevated serum CA 19-9 and mural nodule were independent risk factors of malignancy. Patients with MPD size ≤7 mm without these risk factors had malignancy risk of 2.6 %.
Using the definition of malignancy provided in the 2012 guideline, the MPD size >7 mm criterion was statistically driven. The current morphologic classification of IPMN can be simplified as branch-duct-predominant IPMN (MPD ≤7 mm)’ and main-duct-predominant IPMN (MPD >7 mm). Patients who are determined to have main-duct-predominant IPMN and branch-duct-predominant IPMN with elevated serum CA 19-9 or mural nodule are recommended to undergo surgical treatment.
KeywordsMain Pancreatic Duct Intraductal Papillary Mucinous Neoplasm Mural Nodule Main Pancreatic Duct Dilatation Worrisome Feature
This study was supported by a grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (No. HI14C2640).
Conflicts of interest
The authors disclose no conflicts.
- 23.Adsay NV, Kloppel G, Fukushima N et al (2010) Intraductal neoplasms of the pancreas. In: Bosman FT, Carneiro F, Hruban RH (eds) WHO classification of tumours of the digestive system. IARC Press, LyonGoogle Scholar