Congenital dilatation of the intrahepatic bile ducts with cholangiocarcinoma.

Intrahepatic cholangiocarcinomas were found at necropsy in two previously reported cases of congenital dilatation of the intrahepatic bile ducts. The nature of the developmental abnormality is discussed and compared with other forms of biliary dilatation. Slow-flowing bile for many years probably leads to cholangiocarcinoma.