A choledochal cyst is an abnormal enlargement of the bile duct that is a result of a congenital abnormality of the bile duct. Depending on the location and type of enlargement, there can be different types of choledochal cysts.
This abnormal bile duct causes poor drainage which creates an infection. Some patients develop repeated attacks of pancreatitis since the pancreatic duct may enter into the abnormal bile duct. A vast amount of choledochal cysts are identified during childhood and present with jaundice from the decrease in drainage from the bile duct.
The diagnosis of choledochal cysts is not difficult once the condition is suspected. An ultrasound will show an abnormal bile duct and an ERCP (Endoscopic Retrograde Cholangiopancreatogram) will demonstrate the abnormal enlargement of the bile duct.