Cystic dilatation can occur in extrahepatic, intra hepatic bile ducts or in both.
Incidence in Caucasians is estimated at less than 1 in 200,000 live births. It is more frequently seen in orientals and more than two thirds of reported cases are from Japan. The number of children diagnosed as having congenital cystic dilatation of bile duct has risen dramatically with wide spread rise of ultrasonography. This test should be carried out in any child with the explained abdominal symptoms. Anatomy and Classification Alonso-Lej, Revor and Pasagno proposed the widely used classification.