[Two Cases of Intraductal Papillary Neoplasm of the Bile Duct(IPNB)Resected with Hepatectomy].

Case 1: A man in his 70s was referred to our hospital for further examination of a liver tumor(S3, 3 cm)detected by ultrasonography. Multimodal image examination showed a cystic lesion with solid papillary components located in the S4 accompanied by dilatation of the surrounding intrahepatic bile duct. Although biliary cytology did not indicate confirmed malignancy, the lesion was thought to be an intraductal papillary neoplasm of bile duct(IPNB)with malignant potential, and a left lobectomy was performed. Histopathological examination revealed a papillary tumor in the intrahepatic bile duct which consisted of atypical epithelial cells of pancreatobiliary type, and the lesion was diagnosed as an IPNB with high-grade intraepithelial neoplasia. Case 2: A woman in her 70s was referred to our hospital because of a liver tumor(S4, 8 cm)detected by ultrasonography. Multimodal image examination showed a cystic lesion localized to the liver(S3, 8 cm), and endoscopic retrograde cholangiopancreatography(ERCP)showed continuity of the cyst and the intrahepatic bile duct. The biliary cytology was positive, and the lesion was thought to be a malignant IPNB. After preoperative drainage of the cystic lesion, a left lobectomy was conducted. Histopathological examination showed that the papillary tumor localized to the bile duct and atypical epithelium cells of pancreatobiliary type were infiltrating into the surrounding matrix. We diagnosed this tumor as an IPNB with an associated invasive carcinoma.