Granular cell schwannoma of the extrahepatic biliary system.

We report the case of a woman who presented with a typical picture of cholelithiasis and choledocholithiasis. A percutaneous transhepatic cholangiogram revealed instead a concentric narrowing of the common bile duct and at operation she was found to have a rare, benign tumor of the extrahepatic biliary tree, a granular cell schwannoma.