Carcinoma of the cystic duct.

Two patients with carcinoma of the cystic duct presented with obstructive jaundice due to extrinsic compression of the common hepatic duct by the tumor. Sonography and computed tomography showed dilatation of the intrahepatic bile ducts and gallbladder. In one patient, a calculus seen in the gallbladder neck suggested Mirizzi syndrome. In the other, a small soft tissue mass was indistinguishable from a common duct tumor or an enlarged lymph node. In both cases, direct cholangiography demonstrated extrinsic compression and displacement of the common duct with proximal biliary dilatation and nonvisualization of the gallbladder. Carcinoma of the cystic duct should be considered whenever there is evidence of cystic duct obstruction and/or when cholangiography shows extrinsic mass effect on the common duct.