HMB-45 is a monoclonal antibody that reacts against an antigen present in melanocytic tumors such as melanomas. It is used in anatomic pathology as a marker for such tumors.
HMB-45 was discovered by Drs. Allen M. Gown and Arthur M. Vogel in 1986.[1] The antibody was generated to an extract of melanoma. It reacted positively against melanocytic tumors but not other tumors, thus demonstrating specificity and sensitivity. Moreover, the antibody reacts positively against junctional nevus cells but not intradermal nevi, and against fetal melanocytes but not normal adult melanocytes. HMB stands for Human Melanoma Black.
HMB-45 is nonreactive with almost all non-melanoma human malignancies, with the exception of rare tumors showing evidence of melanogenesis (e.g., pigmented schwannoma, clear cell sarcoma) or tumors associated with tuberous sclerosis complex (angiomyolipoma and lymphangiomyoma).[2]