Computed tomography of hilar cholangiocarcinoma: a new sign.

Thirty-seven patients with histologic proof of cholangiocarcinoma at the confluence were examined by computed tomography (CT) to determine whether this examination is of value in the assessment of these patients for surgery and whether there are any features specific to this type of tumor. Thirty-two patients showed intrahepatic duct dilatation; six of these showed dilatation of ducts in one lobe only. Eighteen patients had intrahepatic low-attenuation areas, while eight had a mass lesion in the porta hepatis. Two of the lesions in the porta hepatis and four of the low-attenuation lesions enhanced. Atrophy of a lobe was noted in seven patients. This feature is not commonly recognized and is suggestive of cholangiocarcinoma rather than other hepatic tumors. The results of this study show that CT provides useful anatomic information preoperatively but that the appearances are nonspecific. Lobar atrophy is highly suggestive of hilar cholangiocarcinoma, either of long-standing or with unilateral portal venous involvement.