Cholangiocarcinoma.

Cholangiocarcinoma is a rare malignancy and accounts for 2% of all malignancies. Incidence is on the increase in the Western world. Cholangiocarcinoma arises from the malignant growth of the epithelial lining of the bile ducts and can be found all along the biliary tree. It can be classified into subtypes based on location: intrahepatic (arising from the intrahepatic biliary tract in the hepatic parenchyma), perihilar (at the hilum of the liver involving the biliary confluence) and distal (extrahepatic, often in the head of the pancreas). Margin status and locoregional lymph node metastases are the most important determinants of postsurgical outcomes.