Some people have dilated bile duct since birth without any apparent cause of obstruction. Most of them will present in their childhood with pain upper abdomen, lump in the abdomen , jaundice or fever. Some will present similarly in adulthood. Rarely it may be an incidental diagnosis while doing an ultrasonography for some other reasons. In patients harbouring the problem for a long time may develop cancer in the biliary tree, liver or pancreas.

There are many types of choledochal cysts depending on which part of the bile duct is involved. Most commonly only the common bile duct is dilated.

Ultrasonography usually picks up the dilated bile duct. MRCP is done to confirm the diagnosis and also for planning of the surgery.

Treatment: Surgical removal of involved bile duct outside the liver and reconstruction with Roux en Y Hepaticojejunostomy (bypass between proximal bile duct and small intestine). In some cases removal of part of the liver may be required. This operation carries a very low risk of complications and excellent long-term outcome.

No known medical or nonoperative treatment of this condition exists.