Reactivity of HMB-45 monoclonal antibody with sweat-gland tumours of the skin.

HMB-45, a monoclonal antibody claimed to be specific for malignant melanoma, has been observed to react with normal eccrine sweat glands and occasionally with normal mammary and bronchial epithelium. In this study we show that HMB-45 also decorates cells in approximately 15% of various sweatgland tumours of the skin. This finding, along with the reported reactivity on mammary carcinomas further outlines the lack of absolute specificity of HMB-45 for cells of the melanocytic lineage.