Cholesterol hepatolithiasis with peribiliary cysts.

A 78-year-old man was admitted to our clinic because of fatigue. Imaging modalities showed beaded stricture and dilation of the intrahepatic left segmental bile duct. Anomalous pancreatico-biliary ductal union and polycystic kidney disease were absent. Resection of the hepatic left lobe was performed. Grossly, cholesterol stones were impacted in the dilated intrahepatic large bile ducts, and multiple tiny cysts measuring 2-8 mm were noted in the peribiliary areas (peribiliary cysts). Histologically, the cholesterol hepatoliths consisted of cholesterol empty spaces and fibrinous materials, and, in places, foreign body giant cells were seen around the cholesterol crystals. The peribiliary cysts were lined by a layer of cuboidal epithelia. They were intimately intermingled with intrahepatic peribiliary glands, and a close association between the two components was recognized in some places. A mild degree of ascending cholangitis was noted. Bile duct anomalies including von-Meyenburg complexes and simple cysts were not recognized. Peribiliary cysts have been reported in various liver diseases, including portal hypertension, portal thrombosis, cirrhosis, hepatocellular carcinoma, and adult polycystic kidney disease. However, to the best of our knowledge, there have been no reports on peribiliary cysts developing in hepatolithiasis. The present case indicates that peribiliary cysts occur in cholesterol hepatolithiasis, and suggests that they are derived from cystic dilations of intrahepatic peribiliary glands.