Computed tomography of carcinoma of the ampulla of Vater.

CT findings were studied in 14 cases with carcinoma of the ampulla of Vater which were all proved by surgery. At pre-operation period, only 4 cases (29%) were accurately diagnosed and other 10 cases (71%) were misinterpreted on CT. The most concomitant error was a confusion with the pancreatic head carcinoma (57%). Although a mass was retrospectively visualized in 4 cases, indirect signs were rather prominent, such as enlargement of the pancreatic head (57%), dilatation of the pancreatic duct (71%) and that of the common bile duct (79%).