Echinococcal cysts in the common bile duct: an uncommon cause of obstruction.

Obstruction of the biliary system due to intraductal echinococcal cysts is a rare but serious presentation of hepatic echinococcal disease. Four cases are described. There was a 50% mortality rate and morbidity was high. The clinical presentation is difficult to differentiate from other disease processes. Careful preoperative sonograms should be taken to detect echogenic cyst material in the biliary system in all patients with hepatic echinococcal cysts. If biliary pigments are seen in the cyst during surgical removal, or if the patient has a recent history of jaundice or cholangitis, intraoperative cholangiography should be done to rule out intraductal cysts, which may cause obstruction.