Presentation
Dilated CBD on ultrasound.
Patient Data
3D image from MRCP shows an anomalous pancreaticobiliary junction, with a high junction of the pancreatic duct with the common bile duct resulting in a long common channel (>15 mm). There is fusiform dilation of the common bile duct, compatible with a type I choledochal cyst.
Case Discussion
Anomalous pancreaticobiliary junctions are thought to be the major cause of type I choledochal cysts. Fusiform dilation of the CBD is thought to be due to reflux of pancreatic enzymes into the CBD, damaging the cells and causing dilation. Type I choledochal cysts are resected due to malignant potential to transform to cholangiocarcinoma.