Klatskin’s tumour

In the surgical literature, CCA is usually classified as either intrahepatic or extrahepatic, and intrahepatic CCA is further classified as either peripheral tumour that arises distal to second-order bile duct branches, or hilar tumour (Klatskin s tumour) that arises from one of the hepatic ducts or the bifurcation of both hepatic ducts. This last entity is classified as intrahepatic, even though the right and left hepatic ducts join outside the liver anatomically. These three types of CCA, peripheral (20%-25%), hilar (50%-60%) and extrahepatic (20%-25%), are traditionally regarded as distinct disease entities from a clinical, therapeutic, and radiological point of view. However, this classification scheme is controversial. Differentiation between peripheral and hilar forms is difficult, since peripheral CCA can spread continuously into the hepatic hilum, whereas hilar CCA often shows continuous infiltration to the intrahepatic bile ducts. In addition, the distinction between hilar CCA and extrahepatic CCA is not clearly defined. 

Direct cholangiography is indicated in patients with peripheral CCA only in rare situations, i.e. to detect contralateral bile duct involvement. The mass and its satellites give the intrahepatic ducts an encased or scalloped appearance. The smooth, variable length stricture affects adjacent ducts within the same hepatic territory. This appearance is usually not mistaken for the peripherally invading Klatskin s tumour, but care is required not to interpret these findings as primary sclerosing cholangitis (PSC). 

Intrahepatic localizations must be distinguished from extrahepatic CCC. They are subdivided into three areas of the large bile duct (1.) the upper third from the hver hilum to the opening of the cystic duct (frequency about 49%) (2.) the medial third of the common bile duct (frequency about 25%) (i.) the lower third reaching to the opening into the duodenum (frequency about 19%). Diffuse involvement of the whole extrahepatic area was found in 7% of cases. Tumours situated in the upper third are designated proximal, central or hilar CCC and are also known as Klatskin tumours. (204) Distal localizations of the extrahepatic CCC must be clearly differentiated from carcinomas of Vater s ampulla and of the pancreas head. 

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