A case of pancreatobiliary-type intraductal papillary mucinous neoplasm of the pancreas with difficulty in preoperative diagnosis

Abstract

A 74-year-old man with jaundice was referred to us to further evaluation of a pancreatic head lesion. Dynamic computed tomography and endoscopic ultrasonography revealed a 50-mm tumor with central necrosis localized in the head of the pancreas. The tumor had peripheral enhancement in enhanced CT and enhanced EUS images. As the tumor was suspected to be a neuroendocrine tumor with cystic degeneration on imaging, the patient underwent pancreaticoduodenectomy. Histological examination revealed that the tumor consisted of atypical epithelium arranged in a complex papillary architecture. Tumor cells were positive for MUC1, MUC5AC, MUC6 and were negative for MUC2 on immunohistochemistry. These findings led to the diagnosis of pancreatobiliary-type intraductal papillary mucinous carcinoma. We have reported a case of pancreatobiliary-type intraductal papillary mucinous carcinoma mimicking a neuroendocrine tumor.