[Choledochal cyst as an unexpected intraoperative finding].

In adulthood, choledochal cysts often surprisingly are discovered during cholecystectomy. Abdominal ultrasonography incorrectly identified the cyst as a dilated or septated gallbladder. Once suspected preoperatively, confirmation of the diagnosis is obtained by ultrasonography or computerized axial tomography, which define its relationship to the vascular structures in the porta. The rapidity and accuracy of ultrasonography favour its use as the initial investigative procedure. Direct cholangiography is the preferred modality for accurate definition of the type of choledochal cyst, ductal strictures, intrahepatic ductal configuration, and polypoid filling defects suggesting cholangiocarcinoma. The well known risk of development of ascending cholangitis as well as cystic cancer, mainly in the adult, indicates the excisional operation for preventing these complications. Cyst excision and Roux-en-Y hepaticojejunostomy is the definitive treatment of choice.