Histopathologic features of hepatocellular carcinoma in Zaire.

The pathology of hepatocellular carcinoma (HCC) was studied based on 223 Zairian HCC cases registered from 1966 to 1985. The observations included the following: (1) hepatitis B surface antigen (HBsAg) status, (2) histologic types, (3) degree of cellular differentiation, and (4) frequency and types of the accompanying cirrhosis. Serum HBsAg was positive in 56.7% of HCC patients and 5.7% of controls (P less than 0.001). Immunohistochemical localization of HBsAg was positive in 53.3% in normal hepatocytes and in 10% in neoplastic cells. Morphologically, mixed type HCC (48.4%), trabecular (31.4%), and compact variants (13.5%) were predominant. Clear cell and pseudoglandular variants were rare (less than 1%). The majority of tumors (83%) were poorly differentiated HCC (Grades: 2-3, 3, 3-4, and 4). Well-differentiated HCC were extremely rare (0.5%). Fifty percent of HCC arose in a cirrhotic liver, predominantly of the macronodular (67.4%) inactive (55%) type. The micronodular cirrhosis was very uncommon (1.1%). These findings clearly show the excess of poorly differentiated HCC in African patients and suggest a possible link between the morphologic features of HCC in Africa and its extraordinary fast-running course.