Dermatofibrosarcoma protuberans of the vulva: clinicopathologic and immunohistochemical analysis of four cases, one with fibrosarcomatous change, and review of the literature.

Only 18 cases of dermatofibrosarcoma protuberans (DFSP) of the vulva have been reported. This article describes the clinicopathologic and immunohistochemical findings of four additional vulvar DFSPs. The median patient age was 54 years (range, 36 to 69 years) and the most common clinical presentation was a slowly growing vulvar mass. The tumors occurred in the left paraclitoral area (1 case), right labium majus (1 case), left labium majus (1 case), and mons pubis (1 case). The tumor size, known in three cases, ranged from 1.2 to 5.0 cm in greatest dimension. Microscopically, the tumors were composed of bland spindle cells with oval or wavy nuclei arranged in a cartwheel pattern; in one case, fibrosarcomatous areas were apparent. CD34 immunostaining was positive in the three cases in which it was performed; positive staining was also seen in the area of fibrosarcoma. Estrogen and progesterone receptor immunostains were negative in three cases. Of the three patients who underwent surgery, one had tumor recurrences every 2 to 4 years for 18 to 20 years but has remained free of tumor in the 7 years since the last excision, one was free of tumor for 12 years before dying of an unrelated cause, and the other has been free of disease for 6 months. The fourth patient refused treatment and has persistent disease in the vulva. This study shows that the behavior of DFSP in the vulva is similar to its behavior in its more common locations.