Metachronous Pancreatic Cancer with Pancreaticobiliary Maljunction Diagnosed Five Years after Cholecystectomy for Gallbladder Cancer, in Which Follow-up Imaging Was Possible Until the Onset of Cancer: A Case Report and Review of the Literature.

Whether or not pancreaticobiliary maljunction (PBM) is a risk factor for pancreatic cancer (PC) is unclear. We present a case of metachronous PC with PBM diagnosed after cholecystectomy for gallbladder cancer, in which follow-up imaging was possible until PC onset. A 63-year-old man who had been diagnosed with gallbladder cancer and had undergone cholecystectomy 5 years earlier developed pancreatitis. Pancreatography revealed PBM, and pancreatic duct brush cytology revealed adenocarcinoma. On reviewing the follow-up images, pancreatic morphological abnormalities, which had not been observed before cholecystectomy, were found to have gradually progressed, suggesting that biliopancreatic reflux led to pancreatic carcinogenesis.