Is capsular retraction a specific CT sign of malignant liver tumor?

The aim of this study was to assess if a liver capsular retraction is a specific CT sign in malignant hepatic tumors. The authors reviewed retrospectively 320 hepatic CT scans obtained in 300 patients during a 3-year period. These patients presented with benign (n = 64) or malignant (n = 236) hepatic tumors. In 7 patients we found retraction of the capsule surrounding the tumor. All these tumors were histologically proven as malignant lesions: 4 metastases (none being chemically treated), 2 peripheral cholangiocarcinomas, and 1 epithelioid hemangioendothelioma. The prevalence of this sign was 2.18% (7 of 320) in this series. This capsular retraction pattern has never been found in hepato-cellular carcinomas (no fibrolamellar in this series) and benign lesions. Liver capsular retraction is an uncommon but specific (100%) sign in malignant hepatic tumors; however, a larger and prospective series is needed.