Case report: Cholangiocarcinoma in a choledochal cyst.

Cholangiocarcinoma is a dreaded complication of unresected choledochal cysts, with an incidence approaching 20-30% in early adulthood. The risk of cholangiocarcinoma remains high where an internal drainage procedure has been performed and the cyst has been partially resected or left unresected. We report a case of cholangiocarcinoma occurring in an unresected choledochal cyst following a drainage procedure in infancy and highlight the role of PET/CT in its diagnosis.