Congenital melanocytic nevus simulating Hutchinson sign.

Abstract

Congenital melanocytic nevus can mimic all the features of melanoma as size, morphological changes, inflammation, ulceration, regression, recurrence after excision.
The clinical features of the here reported congenital nevus simulate a melanoma of the nail matrix, in particular the Hutchinson sign - involvement of the lateral nail fold and hyponychium - and the pseudo-Hutchinson - involvement of the epinychium-.
In the nevi of children affecting the nail lamina also the dermoscopy signs can simulate melanoma, mainly the darker pigmentation, the pseudo-Hutchinson sign, the sign of the triangle - larger proximal part of melanonychia - and the presence of points and globules (2).
This is why the irregularities of the dermoscopic pattern according to some Authors (1) are not a valid discriminating criterion between nevus and melanoma in children (1).