Blood group isoantigens in human benign and malignant vascular tumors

Summary Paraffin material of 31 benign and malignant vascular tumors was investigated with respect to their blood group isoantigen (BG) content by the mixed cell agglutination reaction (MCAR). In capillary hemangioma, BG was found in endothelial cells as well as in solid buds. Benign hemangioendothelioma found in children differed from that found in adults in that in juvenile cases only endothelial cells expressed BG whereas in adult cases BG isoantigenity was present in endothelial cells as well as in intercapillary cellular elements. In pericytomas only endothelial cells were BG positive, whereas the tumor cells lacked BG. Similar results were obtained with glomus tumors. All but one hemangiosarcoma were BG negative. In one case, however, which probably resembled a true malignant hemangioendothelioma (Stout and Lattes, 1967) the tumor cells contained BG in conspicuous amounts.