Dermatofibroma is one of the most common cutaneous fibrohistiocytic tumors, typically presenting as a solitary reddish-brown papule. Over the years, distinct histopathologic variants with atypical biological courses have been explored, such as cellular, aneurismal, and atypical variants. They are significantly more locally recurrent, with a recurrence rate of ~20% each. Eight of 37 patients with deep variants had local recurrences, and 2 cases (5%) showed metastasis. Furthermore, malignant transformation from cellular dermatofibroma has been reported. These aggressive behaviors in some cases support the rationale for the surgical removal of dermatofibromas, and, in particular, a complete excision, given that local recurrence has been associated significantly with incomplete removal. Presently, there are no guidelines for determining adequate surgical margins. Dunkin and colleagues suggested that mesenchymal tumors having a spherical advancing border need to be excised with a wide margin: >5-mm margin is necessary for a “clear” excision and 1 to 5 mm for a “close” excision.
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- In this study, 151 dermatofibromas (DFs) were excised with a margin of 3 mm from the clinical delineation. There was no recurrence noted during the follow-up period of the study (mean, 5.6 years; range, 2.1–7.0 years). Aggressive DF variants (histiocytic, cellular, aneurysmal, and angiomatous) accounted for more than 20% of cases in this study.
- Complete removal of DFs can be successfully achieved with a 3-mm surgical margin.
