How is the classification of cholangiocarcinoma?

Intrahepatic (20%), perihilar (between live and pancreas), and distal extrahepatic (80% both extrahepatic) Perihilar are classified as : Type I (common hepatic duct away from union of right and left) type II (common hepatic w/ union), Type IIIa (common hepatic and right hepatic duct), Type IIIb (common hepatic and left), Type IV (all ducts)