Carcinoma of the gallbladder: CT findings in 50 cases.

Fifty patients with histologically proven carcinoma of the gallbladder were examined by computed tomography (CT). The gallbladder masses were categorized into two broad groups: group 1 (74%) included patients in whom the gallbladder was identified along with a mass lesion; and group 2 (26%), where a large mass was present in the gallbladder fossa with no identifiable gallbladder. Group 1 was further divided into three types according to the nature of the tumor: Type 1, mass almost filling the entire gallbladder lumen; Type 2, a polypoidal mass projecting into the lumen; type 3, an infiltrating tumor seen as focal or diffuse wall thickening. Liver involvement, in the form of localized invasion in the vicinity of the primary gallbladder malignancy, was the most common associated finding (80%). Other ancillary features included presence of calculi, lymphadenopathy, and biliary obstruction. CT was found useful for characterizing and defining the extent of carcinoma of the gallbladder. However, it may not consistently demonstrate involvement of the gastrointestinal tract, omentum, and abdominal wall. CT can also be used for aspiration/biopsy guidance of the gallbladder mass in selected cases.