ABSTRACT
Adenocarcinoma of the biliary tree, or cholangiocarcinoma, is subclassified according to the anatomic site of origin ( Figure 19.1 ). Tumors arising from the extrahepatic bile ducts are the most common. Those involving the biliary confluence, also known as hilar cholangiocarcinoma, account for approximately 60% of all cases. Tumors originating in the mid-or lower bile duct account for 20-30% of all cases and are referred to as distal cholangiocarcinomas. Cholangiocarcinoma arising from biliary radicles within the liver, or intrahepatic cholangiocarcinoma, are the least common, accounting for approximately 10% of cases, although the incidence of this type is increasing. Less than 10% of patients will present with multifocal or diffuse involvement of the biliary tree.
