Treatment of dermatofibrosarcoma of the head and neck with Mohs surgery with paraffin sections

Introduction: Dermatofibrosarcoma protuberans (DFSP) is a rare, low-grade mesenchymal skin tumor. Complete surgical excision remains the mainstay of treatment. Head and neck (HN) DFSP features high local recurrence (LR) rates with wide local excision (WLE) due to both anatomical limitations and functional and cosmetic concerns. Mohs micrographic surgery (MMS) allows complete margin control and is particularly suitable for HN-DFSPs.

Patients and methods: Between 2000 and 2018, 103 DFSP were managed with MMS; 41 (39.8%) were in the HN. Our case series included 23 females (56.1%); mean age: 44.5 yrs. The most frequent sites were the supraclavicular area (10) and forehead (9). Mean size: 5.1 cm (6-16). Previous surgery: 43.9%. We have used permanent-tissue MMS (27 cases) since 2006.

Results: Mean first layer lateral margin: 1.6 cm. Negative margins after first and second stage: 51.2% and 92.7%, respectively. Mean follow-up: 92.6 months (16-225). LR: 1(2.4%). We observed no regional or distant metastasis.

Discussion: We conducted a literature search in PubMed for HN-DFSP and found that this seems to be the largest published series to date. In terms of LR, a substantial difference between WLE 62.5% (9-73%) and MMS 0.8% (0-2.4%) was seen. Forty-one HN-DFSP with unfavorable prognostic factors (mean size: 5.1 cm, previous treatment: 43.9%) were treated. LR: 1(2.4%). Mean follow-up: 92.6 months. Randomized controlled trials are needed, though not likely to be conducted, mainly because of the rarity of HN-DFSP, the need for a long follow-up, and the lack of MMS availability in some institutions. We consider MMS to be the standard treatment for HN-DFSP due to its high cure rate and tissue sparing. Modified WLE with complete margin control appears to be a comparable strategy.