Characteristic clinicopathological features of the types of intraductal papillary-mucinous neoplasms of the pancreas

Objectives: Intraductal papillary-mucinous neoplasm (IPMN) of the pancreas encompasses a spectrum of neoplasms with both morphological and immunohistochemical variations of mucin glycoproteins. Recently, a consensus nomenclature and criteria were histologically defined for classifying these variants of IPMNs into gastric, intestinal, pancreatobiliary, and oncocytic types. The purpose of this study was to determine associations between the histological types and clinicopathological features in patients with IPMN. Methods: Sixty- one patients with IPMN operated upon at Tohoku University Hospital between 1988 and 2006 were retrospectively analyzed. Results: Our series included 27 gastric-, 29 intestinal-, 4 pancreatobiliary-, and 1 oncocytic-type IPMNs. Statistically, the types of IPMN were significantly associated with the histological diagnoses, macroscopic types, and survival of the patients. Characteristically, the gastric- type IPMNs were likely to be diagnosed as benign, to be confined to branch ducts, and to have fair prognoses. On the other hand, the intestinal- type IPMNs were likely to be diagnosed as malignant, occupy the main duct, and have poor prognoses. Because of the small number of pancreatobiliary-type IPMNs and only 1 case of oncocytic-type IPMN, we were unable to determine any of their clinicopathological characteristics in our series. Conclusions: Evaluation of the histological types of IPMN may help to predict the clinical course of patients with IPMN and to design improved clinical management for these patients.