Sonographic Features of Extrahepatic Cholangio carcinoma

The cholangio carcinoma of extrahepatic bile duct is one of the common cause of obstructive jaundice, and the sonography is now the most convenient initial examination of theses cases. The location of 25 proven cases of extrahepatic cholangio carcinoma were classified as Klatskin type(6 cases), common hepatic duct(CHD)(9 cases) and common bilduct(CBD)(10cases). And the sonographic findings were analysed. The characteristic sonographic finding of Klatskin tumor was tqpered narrowing of dilated intrahepatic ducts at portal hepatis without communication between both lobe bile ducts. The CHD, cancer showed communicating dilatation of the intrahepatic ducts, but CHD cancer showed ommunicating dilatation of the intrahepatic ducts, but there was no dilatation of gall bladder or CBD, and in case of CBD cancer, entire biliary trees were usually dilated. With the sonographic findings onle, 19 of 25 cases(76%)were diagnosed as cholangio carcinoma, and 13 of 25 cases (52%) were diagnosed correctly the involved site as well as the malignant nature. The sonographic accuracy of the extrahepatic cholangiocarcinoma was greater in Klatskin tumor than the CHD or CBD cancer. Sonogram is most valuable screening study for cholangio carcinoma, and the CT scan and direct cholangiography such as PTC or ERCP have compensatory roles in detecting hepatic metastasis, regional adenopathy and length of involved bile duct