Abstract
Resected hepatic tissues of 24 patients with primary intrahepatic lithiasis were examined histo-pathologically. Calcium bilirubinate stones, cellular debris and mucinous substances occupied the lumen of large dilated intrahepatic bile ducts. Numerous mucin secreting glands were seen within or around the wall of these bile ducts. Similar structures were demonstrated in two patients with non calculous congenital dilatation of the intrahepatic bile ducts. Cholestasis was often absent in the hepatic parenchyma. Production of intrahepatic gallstones may be caused by not only biliary stasis and infection, but also by intraductal mucin and slow flowing bile in combination with cellular debris, bile pigment and other bile components.