Clinical Presentation

A 29-year-old woman presents with abdominal pain and jaundice.

(A) Magnetic resonance cholangiopancreatography (MRCP) shows fusiform dilatation of the common bile duct (CBD; arrow) distal to the cystic duct. The common hepatic duct (arrowhead) is not dilated. (B) Oblique projection confirms fusiform dilatation of the CBD (arrow) with no dilatation of the remainder of the extrahepatic duct (arrowhead). (C) Magnetic resonance imaging after surgical resection and biliary-enteric anastomosis (arrow) shows persistent dilatation of the CBD despite normal serum bilirubin levels. This appearance may be a normal finding in any patient with a past history of chronic CBD obstruction.

Differential Diagnosis

• Choledochal cyst type IC: This is the most likely diagnosis, given the segmental extrahepatic duct dilatation.

• CBD obstruction: