"Ia: dilatation of extrahepatic bile duct (entire)"
"Ib: dilatation of extrahepatic bile duct (focal segment)"
"Ic: dilatation of the common bile duct portion of the extrahepatic bile duct"
"There is a reported risk of malignancy in type I choledochal cysts ranging from 2.5-28%."
"History and etymology"