Prenatal diagnosis of familial type I choledochal cyst.

Familial choledochal cysts are extremely rare. High-resolution ultrasound now allows for the antenatal diagnosis of these anomalies. After delivery, elective surgical resection should be planned; however, increases in size, deterioration of liver function, and ascending cholangitis frequently force early intervention. We report an unusual occurrence of siblings with type I choledochal cysts and review the existing literature on cause, genetics, classification, diagnosis, and management of this disease.