Abstract
A 61-year-old man visited our hospital because of upper abdominal discomfort and refractory diabetes mellitus. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a pancreatic tumor showing a unique intraductal growth pattern through the whole pancreas and pancreatic parenchymal atrophy. Endoscopic retrograde pancreaticography showed dilatation of the main pancreatic duct filled with tumor thrombi or intraductal tumor growth. Total pancreatectomy was perfomed to achieve a radical resection. Histopathologically, atypical malignant tumor cells showed tubular and papillary growth, and slightly invaded to the pancreatic parenchyma, but were not exposed to the serosa. However, invasion to lymphatic or blood vessels was scarcely seen, and metastases to lymph nodes were not observed. The final diagnosis was pancreatic cancer T3N0M0 stage III. The tumor was immunohistochemically proven to be intraductal tubulopapillary neoplasm (ITPN) based on positive staining of mucin core protein (MUC) 1 and cytokeratin (CK)-7 and negative staining for MUC2, MUC5AC, MUC6, chromograninA, synaptophysin, and trypsin. ITPN is a relatively new concept of pancreatic neoplasms, distinct from other intraductal neoplasms of the pancreas ; pancreatic intraepithelial neoplasia (PanIN), intraductal tubular neoplasm (ITN), and intraductal papillary mucinous neoplasm (IPMN). Here we report this rare case with references to relevant literature.
