An immunohistochemical study of dermatofibrosarcoma protuberans supports its fibroblastic character and contradicts...

Paraffin-embedded material from 26 cases of dermatofibrosarcoma protuberans (DFSP) was investigated by the peroxidase-antiperoxidase technique. Antibodies to S-100 protein, Leu-7 antigen, and neuron-specific enolase (neural markers); to lysozyme, alpha-1-antitrypsin, and alpha-1-antichymotrypsin (histiocytic markers); and to cytokeratin, desmin, vimentin, and factor VIII were used. The tumor cells reacted only for vimentin. In addition, 12 cases showed positive reactions with histiocytic markers (1-3% of the cells; in two cases, up to 10%). These results support a fibroblastic and contradict a neural or histiocytic histogenesis of DFSP.