CT OF HEPATIC-TUMORS - PREVALENCE AND SPECIFICITY OF RETRACTION OF THE ADJACENT LIVER CAPSULE

OBJECTIVE. The purpose of this study was to describe the CT features o f capsular retraction of the liver adjacent to hepatic tumors and to t est the hypothesis that this finding is specific for malignant hepatic tumors. MATERIALS AND METHODS. We first retrospectively reviewed the CT scans of eight patients with pathologically proved malignant hepati c tumors (five secondary and three primary) who had CT scans that show ed retraction of the overlying liver capsule. Then, using criteria dev eloped from the first eight cases, we prospectively studied 253 patien ts with pathologically proved hepatic tumors (75 benign, 178 malignant ) to determine the prevalence of retraction of the liver capsule shown by CT and the specificity of this finding for malignant hepatic tumor s. RESULTS. CT scans in the first eight patients showed two types of c apsular retraction. In seven patients, the retracted liver capsule was smooth and regular. In one patient, capsular retraction was associate d with central ulceration extending to and eroding the liver capsule. Four of 253 patients studied prospectively had hepatic tumors with ass ociated capsular retraction (prevalence, 2%). In those four cases, the retracted liver capsule was smooth and regular. All four tumors were malignant (one fibrolamellar hepatocellular carcinoma, two carcinoid t umors, one colorectal metastasis). CONCLUSION. Capsular retraction of the liver adjacent to hepatic tumors is an uncommon CT finding that ap pears to be specific for malignant hepatic tumors.