Abstract
The patient was a 79-year-old man with dilation of the left bile duct that was observed during follow-up abdominal CT after surgery for cecal cancer. Abdominal MRI, 11 months later, showed a tumorous lesion (26×18 mm) that was slightly enhanced at the umbilical portion of the intrahepatic bile duct. A localized grayish white papillary tumor was observed by peroral cholangioscopy. Under the diagnosis of intraductal papillary neoplasm, extended left hepatic and caudate lobectomy was performed. In the resected specimen, the left bile duct was filled with serous liquid, and a localized papillary tumor (23×13×12 mm) was observed in the intrahepatic bile duct of the left lobe. Pathologically, the tumor consisted of columnar cells containing abundant mucin in the cytoplasm, which proliferated in a papillary pattern in the bile duct; however, the grade of nuclear atypia was slight. The tumor was diagnosed as gastric-type IPNB, which was judged to be a borderline lesion. This case followed a gentle and quiet course, and is considered a valuable case to report the clinical condition of this tumor.
