Characteristics of the sinusoidal wall in human hepatocellular carcinoma

Ultrastructural and immunohistochemical study

Abstract

Twenty-one cases of hepatocellular carcinoma were examined by immunohistochemistry and electron microscopy to clarify the characteristics of the tumor sinusoidal wall. The sinusoidal endothelial cells possessed Weibel-Palade bodies, a few fenestrae and intercellular tight junctions. In the Disse's space like space, incontinuous and multi-layered basal laminae were observed. The sinusoidal wall positive for Factor VIII related antigen was not stained by OKM5. Furthermore, the deposition of laminin was observed on the basal laminae in the Disse's space like space and also in the endothelial cells. In three among four cases of OKM5 positive endothelial cells, the size of tumor was under 3cm in diameter. On the contrary, Factor VIII was revealed in larger tumors over 3cm in diameter and highly frequently found in the cases of poorly differentiated histology when compared with those of OKM5 positive cases.
These findings may suggest that the sinusoidal wall of hepatocellular carcinoma is constituted by sinusoidal endothelial cells in early stage, and then has a character as capillary vessels according as tumor growth.