The American Journal of dermatopathology
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Comparative Study
On the discriminatory value of anti-HPCA-1 (CD-34) in the differential diagnosis of benign and malignant cutaneous vascular proliferations.
The staining pattern of monoclonal antibody anti-HPCA-1 (CD-34) was studied in 95 cases of benign and malignant cutaneous vascular proliferations and compared with other vascular endothelium-associated antigenic markers in paraffin-embedded tissues. The proliferating vessels in 22 cutaneous capillary hemangiomas, 8 lobular capillary hemangiomas, and 1 case of papillary intravascular endothelial hyperplasia stained strongly positively for anti-HPCA-1, and the intensity of the reaction was paralleled by that of factor VIII-related antigen (FVIII), Ulex europaeus lectin-1 (UEA), and vimentin (VIM). ⋯ Nine cases of cutaneous angiosarcoma, two cases of low-grade epithelioid angiosarcoma, and one case of spindle-cell hemangioendothelioma were negative for anti-HPCA-1 and showed variable reactivity for FVIII and UEA; all cases stained strongly positively for VIM. The results of this study indicate that although anti-HPCA-1 shows a high sensitivity for the staining of normal vascular endothelium, its specificity may be restricted to mature, well-formed vessels, therefore rendering its discriminatory value very limited for the identification of poorly differentiated vascular endothelial neoplasms.