A case of intraductal papillary neoplasm of the bile duct with round shape similar to biliary mucinous cystic neoplasms

Abstract

A 64 year-old man came to our hospital for evaluation of left cystic tumor of the liver. Ultrasonography, CT and MRI showed an approximately 2 cm diameter of cystic lesion in the hepatic segment 2. ERC did not demonstrate the communication between the cystic tumor and the bile duct. However, MRCP exhibited the communication between them. Under the diagnosis of the mucin producing bile duct tumor with suspicious malignancy, left hepatic lobectomy was performed. There was papillary solid mass in cystic lesion of the resected liver. The tumor was histologically adenocarcinoma in situ with adenoma component. Ovarian-like stroma was not observe in the wall. Based on these findings, the tumor was diagnosed as intraductal papillary neoplasm of the bile duct (IPNB). We report a case of IPNB showing round shape.