[A case of serous cystadenoma of the pancreas communicating with the main pancreatic duct synchronously diagnosed with pancreatic ductal carcinoma].

A 65-year-old woman who had been followed up for a cystic lesion of the tail of the pancreas was found to have cancer of the body of the pancreas. ERP showed stenosis of the main pancreatic duct (MPD) with dilatation of the distal side of the duct, and communication between the cystic lesion and MPD. She underwent distal pancreatectomy under a diagnosis of intraductal papillary-mucinous neoplasm associated with cancer of the body of the pancreas. Clinicopathologic investigation revealed that the diagnosis of the cystic lesion was serous cystadenoma having the communication with MPD. It was also indicated by the histopathologic findings that inflammatory changes of MPD caused by stenosis might contribute to the development of serous cystadenoma.