[How I treat...pigmented nevi].

Melanocytic naevi are classified according to anatomo-clinical and prognostic criteria distinguishing congenital and acquired lesions. The latter are further identified as common or dysplastic. An atypical melanocytic activation can occur after traumatism (recurrent naevus), severe ultraviolet irradiation and growth hormone intake. The risk of malignant transformation of a naevus and the risk of association to malignant melanoma elsewhere on the body depend on both the nature and number of melanocytic naevi. Hence, the search for suspicious lesions and the comprehensive approach of therapy are directly influenced by the accuracy of the clinical diagnosis.