A Case of Biliary Intraepithelial Neoplasm in a Young Man Diagnosed by Laparoscopic Hepatectomy to Treat Recurrent Intrahepatic Lithiasis and Cholangitis.

Introduction: Biliary intraepithelial neoplasia (BilIN) is defined as a bile duct epithelial tumor with intraductal papillary neoplasia of the bile duct. BiIlN is a precancerous lesion of intrabiliary neoplasia. We performed laparoscopic hepatic resection for recurrent cholangitis due to intrahepatic lithiasis and diagnosed BilIN. This case suggests that it is necessary to consider the possibility of malignancy in cases of repeat cholangitis due to intrahepatic lithiasis.

Case presentation: A 34-year-old man developed cholecystitis due to gallstones at the age of 25 years and underwent laparoscopic cholecystectomy at the age of 26 years. One year later, cholangitis developed, and 2 years later, acute pancreatitis developed due to bile duct stones. Three years later, at the age of 31 years, he underwent endoscopic lithotripsy for bile duct stones and cholangitis. At that time, intrahepatic lithiasis was also detected in segment 6, but there was no stricture in the bile duct, and he was kept under observation. Three years later, at the age of 34 years, cholangitis in the bile duct of segment 6 was observed, and endoscopic nasobiliary drainage was performed. At that time, no strictures or common bile duct stones were found in bile duct of segment 6; however, we decided to perform laparoscopic hepatic resection of the ventral region of segment 6 because of the recurrent cholangitis. Pathological examination revealed bile duct inflammation and BilIN-1 in the bile duct epithelium; the bile duct stump was negative.

Conclusions: We experienced a case of a young patient with recurrent cholangitis due to intrahepatic lithiasis and diagnosed BilIN after laparoscopic hepatectomy. In such a case, it is also necessary to select a strategy that considers the coexistence of precancerous lesions, such as BilIN.