Dermatofibrosarcoma Protuberans


This is an unusual skin cancer that is a low grade sarcoma. Generally if the surgeon can remove this, the results are very good. If the tumor cannot be easily resected with adequate surgical margins then postOp radiation may be useful. The NCCN now has a guideline for this disease (go here) and read the review article below. See You Tube from the Mayo Clinic here, and other reviews here and here

The Role of Radiation Therapy in the Management of Dermatofibrosarcoma Protuberans
Matthew T Ballo, Gunar K Zagars, Peter Pisters, Alan Pollack
International Journal of Radiation Oncology * Biology * Physics . 1 March 1998 (Vol. 40, Issue 4, Pages 823-827)

Dermatofibrosarcoma protuberans (DFSP) is an uncommon, low-grade cutaneous sarcoma recognized for its aggressive local behavior, but low metastatic potential The lesion presents typically during mid-adult life as a painless, nodular cutaneous mass, affecting men more often than women and occurring most often on the trunk, the head and neck area, or the proximal extremity. Although the histogenesis of this tumor is obscure, it has a distinct microscopic appearance characterized by fibroblast-like cells arranged in a storiform pattern. At its periphery, the tumor is widely infiltrating. Surgical excision has generally been the treatment of choice for these lesions. However, local control after excision alone has often been less than satisfactory and multiple local recurrences predispose to distant metastasis . The likelihood of local recurrence is related to the adequacy of surgical margins . Local failure rates have been reported to be 33–60% following conservative resection where the margins were either undefined or less than 2.5 cm . Wider excision margins have been reported to reduce the recurrence rate to 10–25%. In selected patients, Mohs micrographic surgery may further reduce local recurrence rates. Although the results with this technique have been promising, it is laborious and not well suited to large tumors.

An alternative approach is to use radiation in combination with surgery, as has been done for other soft tissue sarcomas . Radiation therapy offers a means for limiting the extent of resection and, hence, the morbidity associated with wide excision at some sites. Remarkably, the use of radiation therapy for DFSP has received little attention in the literature. Some reports have suggested that this disease is relatively radioresistant  but there is no convincing documentation for this contention. Indeed, local control has been reported when radiation was used as sole treatment for gross disease  The principal reports on this subject have recommended radiation as an adjunct to excision. The present series describes our experience at the University of Texas M. D. Anderson Cancer Center (MDACC) with radiation given primarily as an adjuvant to surgical resection.

Dermatofibrosarcoma protuberans is a radioresponsive tumor and radiation to doses of 50–60 Gy should be considered as an adjuvant to resection if margins are positive. Combined conservation resection and postoperative radiation should also be considered for situations where adequate wide excision alone would result in major cosmetic or functional deficits.

Surgical resection has long been the treatment of choice for DFSP and, ultimately, eradicates the tumor in a large proportion of patients. However, DFSP is not easy to eradicate. The need for wide excision margins has been amply documented and is summarized in. It is generally recognized that conventional resection should encompass the tumor with at least 3 cm of margin, including underlying fascia but, even then, recurrence rates of 10–20% can be expected . Mohs micrographic surgical excision has been associated with low recurrence rates (<10%) , and may result in smaller wounds requiring less complicated repair than conventional wide excision. The utility of Mohs surgery might be further enhanced by immunohistochemical (anti-CD34) margin control . The disadvantage is that this is a very labor-intensive method that may be complicated by prior excision and/or recurrence. Such meticulous analysis of the resection margin is particularly difficult for large masses.

An alternative tissue-conserving strategy for selected patients would be the use of combined conservative resection and radiation. This approach would allow for more limited resection, a strategy that has been successful for other soft tissue sarcomas, including low-grade lesions such as desmoids and atypical lipomatous tumors. Although the number of patients in our series is small, it is among the largest reporting on the combination of surgery and radiation for this disease and supports the conclusion drawn by Suit et al.that, in selected situations, radiation at doses of 50–60 Gy is an effective adjuvant to surgical resection . We observed only one recurrence in 19 patients, 10 of whom had already experienced at least 1 prior recurrence and 6 had positive margins, both recognized as adverse factors in surgical series. Likewise, Suitreported only 3 local recurrences in 15 patients, 5 of whom had a history of prior relapse and 12 had positive margins. Taken together, our data and those of Suit et al. reveal only 4 recurrences among 34 patients (12%), 18 of whom had positive margins. Suit et al. also reported that gross disease was permanently controlled in 3 patients receiving 67–75 Gy (19). Thus, DFSP is a radioresponsive tumor.

Although surgery remains the treatment of choice for DFSP, radiation in doses of 50–60 Gy should be considered as an adjuvant to resection if margins are close or positive. Likewise, if the lesion has already recurred despite wide excision, then reresection with adjuvant radiation may offer the best prospect for eradicating the disease. Furthermore, if obtaining wide resection margins would entail significant cosmetic or functional deficit, consideration should be given to lesser resection that minimally encompasses gross disease, with radiation planned to follow. Finally, for lesions unresectable or resectable only by formidable surgery, the use of radiation alone, as suggested by Suit et al.], should be considered