Wide local excision, Mohs micrographic surgery, and reconstructive options for treatment of dermatofibrosarcoma protuberans of the breast: A retrospective case series from Mayo Clinic.

Background: Dermatofibrosarcoma protuberans (DFSP) of the breast is a dermal fibroblastic neoplasm requiring wide excisional margins due to recurrence rates ranging from 26 to 60%. The current literature on reconstructive options and utility of Mohs micrographic surgery for DFSP of the breast is scarce. We describe surgical management of DFSP of the breast at our institution with the largest case series reported to date.

Methods: A retrospective review was performed of women who underwent surgery for DFSP of the breast at our institution between 1990 and 2019. Continuous data was summarized using mean, median, and range; categorical data was summarized with frequency count and percentage. Preoperative lesion size and postoperative defect size were evaluated using 2-sided Fisher exact test, and p-values < 0.05 were considered statistically significant.

Results: Nine patients underwent wide local excision (WLE) with reconstruction including pedicled latissimus dorsi flaps (n = 2), local flap advancement (n = 2), mastectomy with implant (n = 1), oncoplastic breast reduction (n = 1), and skin grafts (n = 3). Nine underwent Mohs micrographic surgery (MMS) with complex primary closure. Mean postoperative maximum wound defect size for WLE was 10.8 cm versus 7.0 cm for MMS with no statistical significance (p = 0.77). Mean preoperative maximum lesion size for WLE was 6.4 cm versus 3.3 cm for MMS with no statistical significance (p = 0.07). Complications with WLE included wound dehiscence in three patients and seroma in one patient. No complications were reported with MMS and primary closure. Recurrence was reported in one WLE patient, which was successfully detected despite flap coverage and resected without complications. Median follow-up for the patients without recurrence was 5.0 years, with two patients in MMS cohort lost to follow-up. Five-year overall survival was 100%.

Conclusions: MMS and WLE are both viable surgical options for managing DFSP of the breast. MMS could potentially minimize reconstructive needs due to smaller average defect size and result in fewer complications but may also result in asymmetry. Immediate flap reconstruction, especially in larger defects, can achieve excellent aesthetic outcomes for patients with DFSP of the breast without compromising detection of disease recurrence.