Association of excision margin size with locall recurrence and survival in patients with T1a melanoma at critical structures

Melanoma guidelines recommend surgical excision with 10-mm margins for T1 melanoma. This procedure may be problematic at sites close to critical structures such as the scalp, face, or external genitalia. A study in Italy compared 10-mm excision versus 5-mm excision for patients with T1a melanoma at critical structures. Local excision with 5-mm margins was not associated with increased risk of local recurrence. Breslow thickness greater than 0.4 mm, mitotic rate greater than 1/mm2, and acral lentiginous melanoma were associated with higher risk of recurrence. The authors conclude that 5-mm margins may be adequate for T1a melanoma excision near critical structures.