What is the recommended treatment for an atypical nevus and melanoma in situ?

Recommended treatment for melanoma in situ is complete full-thickness excision with a minimum of a 0.5-cm margin of normal skin. However some studies suggest that 0.5 cm may be not be the optimal margin for melanoma in situ. Controversy exists regarding the treatment of atypical nevi. Depending on the degree of cytologic atypia, full-thickness excision with margins ranging from 0.2 to 0.5 cm have been recommended. However, for atypical nevi with mild to moderate degrees of cytologic atypia, the question of complete excision is controversial. The latter reflects the lack of consensus about the grading of atypia in nevi, as well as the insufficient data regarding the significance of melanocytic atypia in nevi. It should be stressed that the removal of large numbers of atypical nevi results in significant scarring. Only after thorough evaluation, and when a melanoma cannot be ruled out, should surgical removal be performed. As mentioned above, the vast majority of atypical nevi never become melanomas.