Dermatofibrosarcoma protuberans of the mons pubis.

Dermatofibrosarcoma protuberans (DFSP) is a rare fibrous tumor with intermediate malignant potential and in rare cases the vulva is involved. The most common clinical presentation is a firm plaque with surrounding red to blue discoloration, or less often with multiple small subcutaneous nodules. The authors present a case of a 66-year-old woman who came to the hospital complaining of longstanding painless nodules in the area of the mons pubis. On physical examination, a diffuse area of erythematous induration involving the mons pubis was recognized and within this area there were smaller nodules. The histological diagnosis was dermatofibrosarcoma protuberans. Microscopically DFSP has a storiform pattern of uniform cytologically bland spindle cells, with a characteristic honeycomb pattern of infiltration into the subcutaneous fat. Immunohistochemical staining demonstrates strong positivity for vimentin and CD34. The treatment has been through a wide local excision (WLE), although microscopic tumor projections beyond the central tumor nodule explain the tumors propensity for local recurrence.