5-mm Margin May Be Enough for Excising Small Melanoma in Situ

Sun C, Lim A, De’Ambrosis B, et al. Recurrence Rate of Small Melanoma in Situ on Low-Risk Sites Excised With 5-mm Excisional Margin. JAMA Dermatol (2024).

Zitelli JA. Recurrence Rate of Melanoma In Situ Excised With a 5-mm Excisional Margin. JAMA Dermatol (2024).

Melanoma in situ lesions (MIS) are being diagnosed with increasing frequency, especially in patients with a history of sun exposure. Current practice guidelines recommend removal of the primary lesion with a margin of 5 mm to 10 mm. This study examined the risk of recurrence for MIS lesions excised with a 5-mm margin.

The authors performed a retrospective analysis (n = 351 lesions in 292 patients) from a single clinical practice; all patients were followed for at least 5 years. Superficial spreading melanoma was the most common pathologic diagnosis, and the trunk was the most common lesion location. Included lesions had lengths and widths of 10 mm or less. The data showed that the recurrence rate was 0.9%. The authors concluded that small, MIS lesions in low-risk locations could be safely excised with a margin of 5mm.

In the editorial that accompanied the article, Zitelli noted that recommendations for margin width in patients with MIS are not based on data from randomized trials. The editorial emphasizes the fact that the lesions included in this report were small and located in low-risk body areas. The recommendations for excision margins in patients with MIS provided based on these data cannot be generalized to all patients presenting with these lesions; randomized trials are needed.