Background: There is growing evidence that Mohs micrographic surgery (MMS) is the treatment of choice for dermatofibrosarcoma protuberans (DFSP).
Objective: This study retrospectively compared the recurrence rates of DFSP after MMS with those after wide surgical excision; results at the Mayo Clinic and in the world literature were evaluated. In addition, preoperative tumor sizes and postoperative defect sizes after MMS were compared to determine whether MMS conserved more normal tissue than wide surgical excision.
Methods: The medical records of 84 patients with DFSP who had been treated at the Mayo Clinic were reviewed. They were categorized into two treatment groups: MMS and surgical excision.
Results: Fifteen patients with DFSP who underwent MMS had follow-up data available; one of these patients had local recurrence (recurrence rate, 6.6%; average duration of follow-up, 40 months). Thirty-nine patients had wide excision; four of these patients had local recurrences and one had pulmonary metastases (recurrence rate, 10%; average duration of follow-up, 36 months). A review of the world literature revealed neither local recurrences nor metastases in the 11 studies in which DFSP was treated with MMS. Overall, including our results, the average recurrence rate of DFSP after MMS was 0.6% (range, 0% to 6.6%) and the total recurrence rate was 1.6% (1 of 64). Including our series, DFSP was treated with wide excision in 15 studies; the average recurrence rate was 18% (range, 0% to 60%) and the total recurrence rate was 20% (100 of 489). In eight published studies, DFSP was surgically resected with undefined or conservative excisional margins; the average recurrence rate was 43% (range, 26% to 60%) and the total recurrence rate was 44% (140 of 317). A surgical margin of 2.5 cm to deep fascia was required for complete clearance of all tumors treated with MMS. Twenty-two percent of tumors were removed with a 0.5 cm margin, 50% with a 1.0 cm margin, 67% with a 1.5 cm margin, and 89% with a 2.0 cm margin.
Conclusion: On the basis of our results and data compiled from the literature, MMS may be the treatment of choice for DFSP because of its high cure rate and maximal conservation of tissue.