KBA.62 Melanoma Associated Antigen [KBA.62]

KBA.62 is a novel anti-melanoma antibody. It reacts positively against melanocytic tumors but not other tumors, thus demonstrating specificity and sensitivity. Moreover, it reacts positively against junctional nevus cells but not intradermal nevi, and against fetal melanocytes but not normal adult melanocytes. KBA.62 antibody is useful in identifying malignant melanomas. Metastatic amelanotic melanoma can often be confused with a variety of poorly differentiated carcinomas, large cell lymphomas, sarcomas, spindle cell carcinomas and various types of mesenchymal neoplasms. A keratin-negative, vimentin-rich neoplasm that immuno-reacts with antibody to S-100 protein and with KBA.62 antibody is, with rare exception, a melanoma. Anti-KBA.62 is a useful additional marker for melanoma, specifically in desmoplastic/spindle cell cases and in the context of micro-metastasis in sentinel lymph node.