Volumetric and morphological analysis of intraductal papillary mucinous neoplasm of the pancreas using computed tomography and magnetic resonance imaging.

Objective: The purpose of this study was to predict the malignancy of intraductal papillary mucinous neoplasm (IPMN) based on data obtained by computed tomography and magnetic resonance imaging.

Methods: Sixty-nine patients with IPMN underwent computed tomography, magnetic resonance imaging, and surgery. The tumors were classified pathologically as IPMN (adenoma), IPMN (in situ carcinoma), and invasive carcinoma derived from IPMN, and analyzed morphologically for the following characteristics: tumor size, main pancreatic duct (MPD) diameter, tumor area, MPD area, tumor volume, MPD volume, and intraductal volume (tumors volume + MPD volume).

A pancreatobiliary-type carcinoma in situ at the periphery of a mural nodule developed from a gastric adenoma in an intraductal papillary mucinous neoplasm.

We report a rare case of an intraductal papillary mucinous neoplasm (IPMN) with a pancreatobiliary-type carcinoma in situ (CIS) that originated around a mural nodule formed in a gastric-type adenoma. A 64-year-old man was admitted to our hospital in December 2001 for dilation of the main pancreatic duct, detected on abdominal ultrasonography. Branch-duct-type IPMN (diameter 25 mm) was diagnosed, and because mural nodules were absent, the patient was annually followed up for 5 years.