Cholangiocarcinoma. The diagnosis of cholangiocarcinoma can now be made with greater rapidity and accuracy. In the clinical setting of obstructive jaundice, a CT scan or sonogram may suggest cholangiocarcinoma if dilated intrahepatic ducts are seen with a nondilated extrahepatic biliary tree. The diagnosis is confirmed by cholangiography, and the tumor is staged by the combination of cholangiography and angiography. If the tumor extensively involves both lobes of the liver or involves the main portal vein or hepatic artery, the lesion is considered unresectable. These patients are best palliated nonoperatively, but they should still have an attempt at a tissue diagnosis, as various other lesions can masquerade as cholangiocarcinoma. In comparison, if the tumor is confined to or is distal to the hepatic duct bifurcation, extends into only one lobe of the liver, or involves only the right or the left portal vein or hepatic artery, the lesion may be resectable, and exploration is indicated. As many as half of all patients explored with curative intent will have a successful resection. Various surgical options are appropriate for patients undergoing tumor resection, depending on the site and extent of the lesion. Similarly, several surgical options are possible for palliation in patients with unresectable cholangiocarcinoma. The role of radiotherapy in the management of cholangiocarcinoma is uncertain. Our results, like those of many other retrospective analyses, suggest that radiotherapy prolongs survival after curative resection as well as after palliative stenting. However, further data from randomized studies are necessary to support or refute this impression. Further studies of adjuvant chemotherapy or hormonal therapy will also be necessary to improve patient survival. 