Rounded and velvety epidermal naevus, report of a verrucous form in axillary location.

Rounded and velvety epidermal naevus, naevoid acanthosis nigricans, also called the acanthosis nigricans form of epidermal naevus is an extremely rare entity, with fewer than 15 cases described in the literature. We report the case of a 23-year-old woman with asymptomatic velvety verrucous plaques on her left axilla starting at the age of 14. As far as we know this is the first case of such a verrucous form with only axillar involvement of naevoid acanthosis nigricans. We report this rare case, and we make a brief review of the clinical pathophysiology and treatment of this uncommon tumour.