A Case of Intraductal Oncocytic Papillary Neoplasms of the Bile Duct (IOPN) Metachronously Arising in the Liver

Abstract

62-year-old woman presented with left hypochondriac pain and a giant cystic lesion in the left lobe of the liver was pointed out by CT examination. The tumor appeared a multilocular cystic lesion connecting to the left hepatic duct and included a solid component with internal septum, which were enhanced by contrast CT. Preoperative diagnosis was a intraductal papillary neoplasm of the bile duct or intrahepatic cholangiocarcinoma, and a left hepatic lobectomy was performed. Macroscopically, it was a multilocular cystic lesion, 17 cm in size, containing abundant mucin and papillary nodule. Microscopically, papillary growth of the cuboidal neoplastic cells comprising with eosinophilic cytoplasm and enlarged nuclei in the dilated bile ducts was observed. The tumor was diagnosed as a intraductal oncocytic papillary neoplasm of the bile duct (IOPN). Four years after the left hepatectomy, a tumor, 2 cm in size, was found in the caudate lobe and the partial caudate lobectomy was performed. Pathologically, the secondary lesion revealed the similar morphology as the primary tumor. By genomic analysis, identical mutation in CTNNB1 was detected in both tumors. That is, the metachronous tumor arising in caudate lobe was originated from primary cancer clone, and considered as a postoperative recurrence in the remnant intrahepatic bile duct. This is a rare case of IOPN metachronously arisen in the liver. The repeated surgical attempts were possibly contributed to prolonged survival.