IMMUNOREACTIVITY OF SINUSOIDS IN HEPATOCELLULAR-CARCINOMA - AN IMMUNOHISTOCHEMICAL STUDY USING LECTIN UEA-1 AND ANTIBODIES AGAINST ENDOTHELIAL MARKERS, INCLUDING CD34

The reactivity of sinusoids in hepatocellular carcinoma (HCC), focal n odular hyperplasia, and nonneoplastic liver tissue with various endoth elial markers was investigated to detect any differences that might be of diagnostic relevance. The lectin UEA-1 antibody BMA 120, and antib odies against von Willebrand's factor, CD31, and CD34 were used. KP1 w as employed to detect Kupffer cells. In the normal liver there was onl y focal staining of sinusoidal endothelium in the vicinity of the port al tracts with all of the endothelial markers applied. In the cirrhoti c liver a slightly greater number of sinusoids (mainly in the vicinity of the fibrous septa) stained with UEA-1 and, although to a lesser ex tent, with anti-von Willebrand's factor and anti-CD31. A slight increa se in staining for CD34 was seen in only 1 of the 11 specimens of cirr hotic liver. in focal nodular hyperplasia, there was increased stainin g of sinusoids with all of the markers investigated; staining was conf ined mainly to the periphery of the nodules. HCC exhibited the most ob vious differences in numbers of stained sinusoids and staining intensi ty in comparison with both normal and cirrhotic liver. UEA-1 and anti- CD34 stained large numbers of sinusoids in virtually all of the HCC in vestigated; UEA1 stained a slightly greater number of sinusoids and di d so with slightly greater intensity. BMA 120 and the antibodies again st von Willebrand's factor and CD31 stained a smaller number of sinuso ids and did so with lower intensity; they failed to stain sinusoids in some of the tumors. Because staining of the sinusoids in cirrhotic li ver was minimal with anti-CD34, this antibody proved to be the best of all the markers investigated for distinguishing highly differentiated HCC from nonneoplastic liver tissue. It seems possible that the incre ase in immunoreactivity of sinusoids in HCC with anti-CD34, unlike tha t with UEA-1, anti-von Willebrand's factor, and anti-CD31, is not an e xpression of capillarization, but rather of angiogenesis.