What is a Dermatofibrosarcoma Protuberans (DFSP) and How is It Treated?

• Dermatofibrosarcoma protuberans (DFSP) are rare tumors of the deeper layer of the skin that can be aggressive in the location where they arise but rarely metastasize (spread to other organs). DFSP are rare tumors grouped into a type of tumor class called sarcomas.

  Sarcomas are cancerous tumors that can arise from most any cell type in the body like bone, skin, blood vessels or fat. DFSP make up about 20 percent of all cutaneous sarcomas diagnosed and present equally in men and women.

  DFSP’s generally present as a slow growing, non-painful, firm, raised nodule or plaque on the skin or underneath the surface of the skin (Figure 1). They can occur as a firm raised area on your skin and can occur anywhere on the body with most found on the torso. In rare circumstances, they can grow to be quite large. DFSP can occur anywhere on the body. The diagnosis is frequently delayed as the lesion may be initially thought to be non-cancerous.

  The first step in diagnosis is achieved with either a punch or excisional biopsy. Under the microscope the cells appear like  ‘‘cartwheels’’ or a ‘‘whirling’’ pattern. DFSP grow in an irregular fashion in the skin, with microscopic tentacle-like projections growing from the center of the tumor. These projections make DFSP difficult to treat.

  After a diagnosis it is important to see a physician that has experience with these rare tumors. Some options for removal include an excision in the operating room by a surgeon or possibly using a technique called Mohs surgery performed by a dermatologist. Depending on where the DFSP is located some patients require reconstruction at the excision site by a plastic surgeon with either a skin graft or flap.

  Despite frequent prolonged delays in diagnosis, the chance of distant spread is very low with a rate of less than 2–4 percent. However, the local recurrence rate (the chance of it coming back) of DFSP has been reported to be as high as 50 percent within three years in some series. This high recurrence rate is related to unrecognized presence of tumor at the edges of resection (positive margins).

  We published a series demonstrating very low rates of recurrence using a multidisciplinary approach with careful analysis of the margins. Although it is very rare, we sometimes recommend radiation or chemotherapy after surgery, especially in patients with recurrence of the DFSP.