An<unk>  is a conduit that transports bile and is considered to be supernumerary or auxiliary to the biliary tree. It may be described by its location relative to the gallbladder as supravesicular (superior to the gallbladder body) or subvesicular (inferior to the gallbladder body).
Accessory bile duct
Annular pancreas
Accessory pancreas
Bile duct hamartoma
Pancreas divisum
Porcelain gallbladder
Choledochal cysts
Biliary microlithiasis