Figure 1. Schematic image of the anatomical locations of intrahepatic, perihilar, and distal cholangiocarcinoma (CCA).

CCA is categorized on the basis of its location within the biliary tree. Intrahepatic CCA is found proximal to the second-order bile ducts, perihilar CCA is found between the second-order bile ducts and the convergence of the cystic duct and the common duct, and distal CCA is found between the cystic duct and ampulla of Vater.