A case of intraductal tumor of the liver incidentally found with diarrhea symptom

Abstract

A 45-year-old man was referred to our hospital with dehydration due to frequent (7-8 times/day) diarrhea. Contrast-enhanced CT (CE-CT) revealed a cystic tumor measuring 20cm in diameter with roundly humping shape at the left lobe of the liver, and there were enhancing papillary lesions in the peripheral cystic tumor. In ERCP, a lot of serous bile juice was flowing out from Vater's papilla, and the ERC finding showed communication between the cystic lesion and the biliary duct branch. Extended left hepatic lobectomy was performed based on the diagnosis of intraductal papillary neoplasm of the bile duct (IPNB). On histopathological examination of the resected specimen, not papillary but tubular tumors existed in saccular dilated bile duct. Immunostaining findings were positive expression of MUC6, negative expression of MUC1 and MUC2, and weakly positive expressions of MUC5AC. The findings of tubular proliferative morphology and MUC staining did not match with IPNB or intraductal tubular papillary tumor; we therefore finally diagnosed intraductal tumor of the liver. After operation, the diarrhea symptom was improved and there was no recurrence during five years. We considered the large amount of serous bile juice produced from the tumor to be the cause of frequent diarrhea.