Enhanced CD34 expression of sinusaid‐like vascular endothelial cells in hepatocellular carcinoma

Abstract
The immunohistochemlcal expression of CD34 (human hematopoletic stem cell and endothelial cell marker) and laminin were studied In chronic liver diseases and hepate cellular carcinoma (HCC) to elucidate whether their expression reflected phenotypic differences between non-cancerous slnusoids and sinusoid-like tumor vessels. In normal liver, hepatic sinusoids were always negative for CD34 and lami-nin. In chronic hepatitis and cirrhosis, the two antigens were sparsely expressed in capillarized sinusoids at periportal and petinodular area. In advanced HCC, CD34 was strongly and diffusely expressed by the endothelial lining of sinusoid-like tumor vessels. However, early-stage HCC showed a wide spectrum of CD34 expression from negative to focal and diffuse, strongly positive staining in sinusoid-like vessels. Laminin was strongly expressed in advanced HCC but not in early-stage HCC. The results Indicate that the enhanced expression of CD34 by sinusoidal endothelial cells may reflect the phenotypic change of endothellal cells in chronic liver diseases and HCC, and that the expression may correlate with the processes of angiogenesis induced by hepatocarcinogenesis.