Atrophic and Plaquelike Dermatofibrosarcoma Protuberans

It is clinically important to realize that dermatofibrosarcoma protuberans (DFSP) often begins as a nonprotuberant plaque and occasionally persists as such. Cases of what has been called atrophic DFSP have recently been reported. None of these cases varied either histologically or prognostically from classical nodular DFSP, and all should be considered part of the clinical spectrum of DFSP. However, histologic variants of DFSP can portend a worse prognosis. The fibrosarcomatous variant, which is fascicular and does not immunostain with anti-CD34, is an example. Recently, another fascicular variant that does positively immunostain with anti-CD34 has been described as plaquelike DFSP. We described a case of a DFSP that had histologically banal, slender fascicles of anti-CD34 immunostaining spindle cells in a clinically nonprotuberant plaque despite subsequently developing a nodule with typical storiform histology. The importance of anti-CD34 immunoperoxidase staining in the diagnosis and prognosis of DFSP variants is emphasized.