[Biliary peritonitis after traumatic rupture of a choledochal cyst].

Choledochal cysts are rare congenital malformations of the biliary tract. Traumatic rupture of a choledochal cyst can be misleading. An 11-year-old boy was admitted for peritonitis and intestinal occlusion after blunt abdominal trauma, evolving over 48 h. Laparotomy revealed bile ascites and a suspected duodenal perforation. After referral to our center, a CT scan showed a perforated choledochal cyst. Six months later, a complete excision of the cyst was successfully performed. This treatment is mandatory because of the risk of further complications such as lithiasis, pancreatitis, cholangitis, biliary cirrhosis, and malignant transformation (cholangiocarcinoma).