Use of 18F-FDG PET/CT for the Evaluation of Carcinoma Arising From Choledochal Cysts.

Choledochal cysts are rare congenital anomalies of the biliary tree, which are more prevalent in female Asian population. Malignant transformation occurs in 10% to 30% of adults with choledochal cysts. A 39-year-old man presented with abdominal pain for 2 months, with irregular thickening of bile duct wall on ultrasound and enhanced CT. Staging with F-FDG PET/CT demonstrated lymph node and liver metastasis. F-FDG PET/CT may become a valuable imaging procedure in diagnosing and staging of carcinoma arising from choledochal cysts.