Investigation of resected multinodular hepatocellular carcinoma: assessment of unicentric or multicentric genesis from histological and prognostic viewpoint.

Abstract

Multicentricity of hepatocellular carcinoma (HCC) is attracting a great deal of attention at present. However, few studies have focused on the prognostic comparison between unicentric and multicentric multinodular HCCs. The aim of this study is the reevaluation of histologic criteria of multicentric HCC and a prognostic comparison between the two groups mentioned above. Forty-nine cases with intrahepatic multiple nodules of HCC, by gross examination, among 184 consecutive resected HCCs were examined clinicopathologically. These cases were divided into three groups: group A, cases suggestive of multicentric genesis; group B, unicentric cases; and group C, indeterminate cases. Histopathological characteristics and the cumulative survival rates were compared among these groups. Five cases were categorized as group A, 36 cases as group B, and eight cases as group C. Nodules in group A were smaller than 2 cm in diameter, situated discretely and well differentiated, and with neither vascular nor capsular invasion. Most of the nodules lacked a tumor capsule and had an irregular border. In the 36 cases of group B, all main tumors had vascular and/or capsular invasion. The cellularity index was almost the same in all groups. The cumulative survival rate of group A was better than that of group B or group C. Small multiple nodules of well-differentiated hepatocellular carcinoma without vascular and capsular invasion might be multicentric, and these early detections and operations could result in a fairly good prognosis, despite the multiple HCC nodules.