RT Journal Article SR Electronic T1 Histogenesis of Kaposi's sarcoma in patients with and without acquired immune deficiency syndrome (AIDS). JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 742 OP 749 DO 10.1136/jcp.39.7.742 VO 39 IS 7 A1 Jones, R R A1 Spaull, J A1 Spry, C A1 Jones, E W YR 1986 UL http://jcp.bmj.com/content/39/7/742.abstract AB Immunohistochemical studies were performed in thirty skin biopsies from patients with Kaposi's sarcoma, who did and did not have the acquired immune deficiency syndrome (AIDS). Tumour histogenesis was rigorously tested using a battery of endothelial cell markers, which included two new monoclonal antibodies, EN4 and PAL E. These are both specific for endothelial cells and can be visualised in appropriately fixed paraffin embedded tissue. Whereas EN4 labels all endothelial cells, PAL E is negative in endothelium of lymphatic derivation. Lectin binding with Ulex europaeus agglutinin 1 (UEA-1) and the presence of factor VIII related antigen (FVIIIRA) and laminin were also examined. In nodular lesions of Kaposi's sarcoma the spindle cell areas were positive with EN4 and UEA-1, negative with PAL E, and showed focal staining for FVIIIRA and laminin. These results confirm that the tumour is of endothelial cell origin. Six patch stage lesions showed a network of angulated spaces, lined by cells that were positive with EN4 and UEA-1, negative with PAL E and anti-FVIIIRA, and showed only weak staining for laminin. This pattern was observed in both AIDS and non-AIDS related cases and strongly favours a lymphatic derivation for the tumour. This has important implications as it suggests that lymphatic endothelium may have special characteristics that lead to neoplastic transformation in patients with retrovirus infection.