In this study, 20 cases of eccrine spiradenoma have been examined using monoclonal antibodies to identify the nature of the epithelial, as well as the non-epithelial, cellular components of this tumour. The results indicate that there is striking similarity between the epithelial cells of eccrine spiradenoma and the normal cells lining eccrine apparatus. An interesting finding was the presence of abundant T-lymphocytes and Langerhans' cells within the tumour lobules. Additionally, endothelial-lined vascular channels and neurofibrils were prominent in larger lesions.