[Contribution of monoclonal antibody D 47 in the study of sweat gland pathology]

D 47 is a monoclonal antibody (IgG2) reacting with a surface antigen of cortical thymocytes. On normal human skin, D 47 was found to react with a cytoplasmic antigen of the cells of the secretory portion of eccrine sweat glands (ESG). No reactivity with D 47 is detected on the excretory part of ESG, on apocrine glands and all other cutaneous structures. In this work we studied through an indirect immunofluorescence method on frozen skin sections the reactivity pattern of D 47 on a group of epithelial skin tumours of certain or alleged glandular differentiation. These consisted of: eccrine spiradenoma (ES, 1 case); chondroid syringoma (CS, 1 case); syringomas of the eyelid (1 case); clear-cell hidradenocarcinoma (1 case); eccrine porocarcinoma (1 case); naevus sebaceus of Jadassohn (2 cases, one of which associated to a syringocystadenoma papilliferum); clear-cell acanthoma (1 case); extramammary Paget's disease (3 cases); basal-cell epithelioma (2 cases). D 47 yielded in a strong labelling of a significant proportion of cells in the cases of ES and CS, while on the remaining tumours, apart from normal ESG occasionally present in the peritumoral connective tissue, no reactivity was seen. From this study it becomes clear that D 47 represents an immunohistologic marker of eccrine-secretory differentiation and that it can be applied in the investigation of the differentiation and of the differential diagnosis of sweat-gland neoplasms.