Clinicopathologic features of encapsulated hepatocellular carcinoma: a study of 26 cases.

The clinicopathologic features of 26 cases of hepatocellular carcinoma (HCC) surrounded by a grossly distinct capsule-like fibrous tissue were studied. The frequency of this type was 10.3% among autopsy cases of HCC. The mean age of the patients was 64.1 years, which was significantly older compared with that of 143 cases of nonencapsulated HCC. Hepatitis-B surface antigen in serum was positive in 18.7% of the cases studied, the positivity rate being lower than that of HCC in general. Histologically, the tumor was relatively well differentiated and the capsule was the product of slow expanding growth. Intravenous tumor invasion was less frequent compared with other types of HCC. Clinically, celiac angiography proves to be a most useful diagnostic method; a thick capsule may be demonstrated as a thin radiolucent rim around the mass. The clinical course from the early stage is protracted and, if detected early, this type of HCC may be removed surgically.