Klatskin tumor is

Hilar cholangiocarcinoma is also known as Klatskin tumor Bismuth - corlette classification of Hilar Cholangiocarcinoma Type I- Tumor confined to hepatic duct, not involving the main biliary confluence Type II- Tumor involving the main biliary confluence but not extending to the right or left ducts Type IIIa- Tumor extending upto the right secondary biliary confluence Type IIIb- Tumor extending upto the left secondary biliary confluence Type IV - Tumor extending bilaterally to the secondary biliary confluence Ref : Sabiston 20th edition Pgno :1514-1518