In cases of mild and moderate dysplastic nevi (DN) with microscopically positive margins and no concerning clinical residual lesion, observation, rather than re-excision, was a reasonable management option, according to a recent study. Researchers conducted a retrospective cohort study of patients with biopsy-confirmed DN with positive histologic margins. A consecutive sample of 1,473 histologically confirmed DN was identified using surgical pathology databases at the study sites: 590 cases in 498 patients met criteria (mean age, 57.6 years; 90% male). Researchers found:

• Cases in the observation group were more likely to demonstrate nevus recurrence that those that were re-excised (3.3% vs 0%).

• 6 of 304 (2.0%) observed DN subsequently developed melanoma at the same site, compared with 1 of 170 (0.06%) that were re-excised.

• Only 1 care of thin invasive melanoma (≤1 mm) was observed, and no deaths from melanoma arising from biopsy-proven DN occurred through the latest dermatology follow-up.