Recognition of malignant melanoma by monoclonal antibody HMB-45. An immunohistochemical study of 200 paraffin-embedded cutaneous tumors.
Antibodies to S-100 protein have been used widely as markers of malignant melanoma, despite abundant evidence that they are non-specific for this neoplasm. Hence, alternatives to these reagents are desirable in diagnostic dermatopathology. We evaluated the characteristics of a new monoclonal antibody (HMB-45) which does have putative specificity for melanoma, and compared it with a polyclonal anti-S-100 reagent in immunohistochemical staining of 67 melanomas of the skin and 133 non-melanomatous cutaneous neoplasms. All specimens were formalin-fixed and paraffin-embedded, and were studied with the avidin-biotin-peroxidase complex technique. HMB-45 labelled 62 of 67 melanomas, while anti-S-100 recognized all tumors of this type. On the other hand, S-100 also was expressed by 15 of the non-melanocytic neoplasms, all 133 of which were HMB-45-negative. The only cases of melanoma that were missed by the latter reagent were of the spindle-cell type. Hence, HMB-45 was 100% specific and 93% sensitive, relative to a diagnosis of malignant melanoma in paraffin sections. Epithelioid and small-cell neoplasms are reliably recognized by this antibody, but it would appear that spindle-cell melanomas must be detected by other immunohistochemical means.
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D008545:Melanoma / Q000276:immunology / Q000473:pathology*; D009418:S100 Proteins / Q000276:immunology; D012878:Skin Neoplasms / Q000276:immunology / Q000473:pathology*
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D009418:S100 Proteins