Carcinoma in choledochal cyst.

Two cases of choledochal cyst associated with adenocarcinoma are documented. The classical triad of jaundice, abdominal mass, and pain is not distinctive enough to make the preoperative diagnosis of a choledochal cyst and its associated malignancy. Operative cholangiogram is a very important investigation, as by the presence of a filling defect in the cyst it can suggest malignancy. In our cases the diagnosis of malignancy was made at operation, which was confirmed by histopathological examination. Internal drainage procedures in combination with chemotherapy by 5 FU rendered both the cases asymptomatic.