Pancreatic adenosquamous carcinoma coexisting with intraductal papillary mucinous neoplasm presenting with an unusually high accumulation of FDG-PET

Abstract

A 76 year old man who was referred to our hospital presented with jaundice and a pancreatic head tumor. Enhanced CT showed a solid mass 26mm in diameter at the pancreatic head and also detected a hepatic tumor 8mm in diameter at segment 8. In addition, MRI showed a cystic tumor adjacent to the pancreatic head tumor. FDG-PET showed strong FDG uptake in areas corresponding to the pancreatic head and hepatic tumors in which SUVmax values were 15.6 and 7.56, respectively. Clinical diagnosis was pancreatic adenocarcinoma and hepatic metastasis. A pylorus-preserving pancreaticoduodenectomy and partial hepatectomy were performed according to the patient's and family's wishes, and due to the unusual isolated hepatic metastasis. Histopathologic evaluation showed that a component of a squamous cell carcinoma intermingled with that of a ductal adenocarcinoma in the pancreatic and hepatic tumors. In addition, proliferation of papillary columnar epithelium was detected at the branch of the pancreatic duct corresponding to an intraductal papillary mucinous neoplasm (IPMN), The IPMN did not have continuity to the ductal adenocarcinoma or squamous cell carcinoma. Therefore, the final histopathologic diagnosis was a coexistence of pancreatic adenosquamous carcinoma and IPMN.