Congenital Naevus: Case Report of an Atypical Atrial Location

Abstract

Congenital naevi are a benign proliferation of melanocytes. Present at birth or appearing in the first weeks of life, they have the appearance of light to dark brown lesions, sometimes bluish, more or less hairy. It is a non-hereditary mosaic pathology. They are due to postzygotic somatic mutations involving key proteins in the mitogen-activated protein kinase pathway, mainly NRAS and BRAF. Its prevalence is estimated to be between 1 and 3% of newborns. This disease can affect any part of the skin. There are 3 types of naevi: small, medium and large naevi then called giant. The objective was to discuss the clinical and therapeutic aspect of a congenital auricular naevus of medium size. We report the case of an 18 years old girl presenting a sessile tumefaction at the level of the concha of the right auricle that appeared from birth, firm, rough, unique, about 5 cm in diameter, homogeneous in color, pigmented, hairy, painless to palpation, apyretic sometimes pruritic without any other associated sign. The diagnosis of benign congenital naevus was clinically made after confirmation by the dermatologist. Surgical removal was performed. The postoperative course was simple with complete healing after one month. The middle congenital naevus is a benign tumor linked to a genetic variation of low incidence, which is all the more rare as it is located on the ear, thus having a significant psychological impact due to its often unsightly appearance. The diagnosis of this genodermatosis is essentially clinical. When it is an isolated nodule, as in our study, total surgical removal is a good alternative with simple after-effects and an almost non-existent risk of malignant transformation.