Dermatofibrosarcoma protuberans: a report on 29 patients treated by Mohs micrographic surgery with long-term follow-up and review of the literature.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is an uncommon tumor of the skin. Clinically, it often masquerades as a benign, indolent tumor on the trunk and extremities. Microscopically, it extends far beyond assessed clinical margins, spreading locally in the dermis, subcutaneous tissue, and muscle. The local recurrence rate in patients with DFSP who undergo wide local excision ranges from 0% to 21%. Recent preliminary reports indicate more consistently favorable cure rates with Mohs micrographic surgery (MMS). However, to date only a few scattered reports have documented long-term 5-year follow-up. The authors present data on 29 patients with DFSP who underwent MMS. In addition, they reviewed the medical literature to summarize the accumulated experience of MMS treatment in the management of DFSP.

METHODS: The authors conducted a retrospective review of a series of 40 consecutive patients with DFSP who underwent MMS over the last 20 years. Of these, there were 29 patients with > 5 years of follow-up who formed the basis of the current review. The literature also was searched for patients with DFSP who underwent MMS with > 5 years of follow-up

RESULTS: At the University of Wisconsin Mohs Surgery Clinic, 29 patients with > 5 years of follow-up were treated. There were 16 women and 13 men. Eight patients developed recurrent disease after previous non-Mohs treatment. Site distribution was 45% head and neck and 55% trunk and extremities. In the current series, there were no local recurrences, with a local 5-year cure rate of 100%. In the literature review, which included the current series, there were 136 patients with DFSP who underwent Mohs surgery with > 5 years of follow-up. Nine patients in the current series developed local recurrences, including five patients who underwent a second Mohs procedure. The local cure rates after the first and second Mohs surgeries were 93.4% and 98.5%, respectively. The rate (percent) and time to local recurrence was 50% at 3 years and 75% at 5 years. However, 25% of local recurrences appeared late, after the usual 5-year recommendation.

CONCLUSIONS: In a series of 29 patients with of DFSP and in an accompanying update of the medical literature, 136 patients with DFSP underwent MMS with > 5 years of follow-up. There were no regional and/or distant metastases. However, late recurrences beyond the usual recommended 5-year follow-up may occur. Therefore, all patients with DFSP, especially those with recurrent tumors, should be followed for an extended period. The accumulated data continue to confirm that, when DFSP is discovered early and is accessible readily to excision by MMS, a favorable outcome can be expected with minimal trauma or sacrifice of adjacent normal structures and with a low recurrence rate.