Klatskin tumor is a malignant tumor located at the junction of which ducts?

• A. Right and left hepatic ducts
• B. Common bile duct and cystic duct
• C. Portal vein and hepatic artery
• D. Intrahepatic ducts

Answer: (A)

Klatskin tumor arises at the junction where the right and left hepatic ducts meet—the hilar confluence at the porta hepatis. This location, at the hepatic duct bifurcation, is where bile ducts from both lobes converge to form the common hepatic duct, which then becomes the common bile duct after joining the cystic duct.

Understanding this helps distinguish it from tumors at other ductal sites. It is not at the junction between the common bile duct and the cystic duct (that’s where the cystic duct joins to form the common bile duct), nor is it located at the vessels of the portal triad (portal vein and hepatic artery) or confined solely to intrahepatic ducts within the liver. The hallmark is its position at the hepatic duct confluence, the hilum.