[Choledochal cysts. A rare prenatal diagnosis].

Forty to sixty percent of main bile duct cysts are diagnosed before the age of 10 years, often at the time of a complication. Current progress in echography now makes it possible to diagnose such cysts antenatally. Wze report a case discovered at 33 gestation and focus on the difficulty of formal antenatal diagnosis and the unpredictable, sometimes rapid, course of the disease. The main prognosis factor is the development of complications, especially liver fibrosis. Antenatal suspicion of main bile duct cyst is important as they can then be managed early after echographic confirmation during the first days of life with the potential reduction in severe complications.