Most are of the infiltrating nodular or diffusely infiltrating type. Purely nodular or papillary are less frequent subtypes
Perihilar tumours involving the bifurcation of the ducts are also known as Klatskin's tumours. More than 95% are adenocarcinomas
are cancers arising from the bile duct epithelium. These can be divided depending on their location in the biliary tree: intrahepatic or extrahepatic (perihilar and distal).
