Immunoperoxidase localization of factor VIII in angiosarcomas.

Factor VIII-related antigen was studied in 28 cases of angiosarcoma from different sites by means of the immunoperoxidase technique. Positive immunostaining was observed in 23 cases. Five cases composed preponderantly of solid areas, with little vasoformative activity, showed negative immunostaining. This technique is of value in diagnosing tumors of endothelial origin.