[Pathological study of hepatolithiasis with special reference to unusual cases]

Morphological survey was performed in 140 liver specimens of hepatolithiasis which were collected from several pathological and surgical Departments in Japan. Among them there were 19 cases with unusual features suggestive of presumed lithogenic processes. They consisted of association of congenital dilatation of biliary tree (5 cases), association of stenosis or obstruction of biliary tree occurring prior to lithiasis (4 cases), association of anomalous communication between biliary tree (1 case), presence of serous glands simulating to pancreatic exocrine glands in biliary tree (1 case), association of non-biliary hepatic cirrhosis (4 cases), association of chronic ulcerative colitis (1 case), intrahepatic cholesterol stone (2 cases) and association of granulomatous cholangitis (1 case). Chronic proliferative cholangitis which is consistently seen in a common type of hepatolithiasis was found in about a half of these unusual cases and not in the remaining cases. Based on the observations of these unusual cases, the following suggestions were obtained: dilatation, bile stasis or cholangitis may be a lithogenic factor of hepatolithiasis, and chronic proliferative cholangitis associated with a numerous amount of mucinous glands is not always a prerequisite lesion and exerts a promoting and accelerating effect in hepatolithiasis.