Invisible at birth congenital melanocytic nevus.

Abstract

The diagnosis of invisible at birth congenital melanocytic nevus should be reserved (1) to nevi that are not visible at birth but appear within the first months of life, when they already appear with dimensions greater than those of an acquired nevus and above all when they do not grow further significantly. We believe we are facing little pigmented junctional congenital melanocytic nevi and therefore little or no visible at birth that becomes evident when the production of melanin increases. Among the factors that can stimulate the production of melanin the first place belongs to solar radiation, as demonstrated by the fact that these nevi often arise during the summer period (1). Even the hormonal stimuli responsible for the hormonal crisis of the first months of life could explain the appearance of these nevi, as suggested by the increase in nevi at puberty (2).