An immunohistochemical study of the blood vessels within primary hepatocellular tumours.

We studied the blood vessels in routinely formalin-fixed and paraffin-processed tissue from 18 hepatocellular carcinomas, three "small" hepatocellular carcinomas, and 15 benign nodular lesions representing a spectrum of conditions with which liver cell carcinomas may be confused. These were stained for a basement membrane component (collagen IV) and endothelial markers (Factor VIII-related antigen, Ulex europaeus lectin binding, and QBEnd10). The staining pattern of normal and cirrhotic liver was also examined in tissue removed with these tumours. There was an increased expression by small blood vessels for collagen IV in carcinomas and benign lesions compared with cirrhotic nodules. All endothelial markers (Factor VIII-related antigen, QBEnd10, and Ulex europaeus binding) were best expressed in liver cell carcinomas. These differences were of degree and pattern, and no single marker distinguished benign from malignant lesions. The differences in staining pattern taken together with other clinical and pathological information should be useful in diagnosis particularly of small liver cell carcinoma. The differences between benign and malignant lesions support the idea that malignant neoplastic blood vessels in the liver are of a different basic biological type from normal hepatic sinusoids, and this difference could be exploited further in future therapy.