Cholangiocarcinoma arising in a choledochal cyst: diagnostic value of computed tomography and ultrasonography.

A case of cholangiocarcinoma arising in a choledochal cyst (type II or biliary cyst in Alonso-Ley classification) in a 53-year-old woman is presented. Ultrasonography and computed tomography provided the correct preoperative diagnosis. The value of these modalities in presurgical planning is illustrated.