Choledochal malformations

Type I: Fusiform dilation of the common bile duct
Type II: Bile duct diverticulum
Type III: Saccular dilation of the common bile duct in the ampulla, also termed choledochocele
Type IV: Multiple cystic bile duct dilations
    - Type IVA: Intra- and extrahepatic cysts
    - Type IVB: Extrahepatic cysts only
Type V: Fusiform or saccular cystic dilation of the intrahepatic bile ducts, whether or not associated with hepatic fibrosis (Caroli disease)
Type VI: Isolated cystic dilations of the cyst duct^[1]