Giant congenital pigmented naevus with unusual presentation and early malignant transformation in a Nigerian infant: Case report and review of the literature

Abstract

A six month-old female infant with a giant congenital pigmented naevus isreported because of the rarity and unusual presentation and early malignanttransformation. It was the first case to be documented in our centre. There wasan extensive giant, darkly pigmented naevus of the "bathing trunk" distributionnoted at birth, associated with multiple darkly pigmented smaller naevi scatteredover the trunk and limbs. Bv the third month of life large pigmented lesion beganto demonstrate small papillomatous projections studding the entire surface and atage six months nodular and warty excrescences appeared including a largepedunculated spherical mass attached to the anal verge. The labia majora becameanatomically disfigured by these nodular, warty lesions of various sizesassociated with the large pigmented hairy naevus. Histological examination of theexcised large perianal and vulvar nodules showed the typical picture of anintradermal naevus consistent with giant congenital pigmented (melanocytic)naevus. The deeper portions of the lesion showed features of malignanttransformation. The rapidity of evolution of the lesions including histologicfeatures of early malignant transformation and the gross disfiguring of thegenitalia and perineum are uncommon presentation of this melanocytic naevus. Inview of the early malignant transformation immediate surgical treatment wasindicated. Unfortunately the patient was lost to follow-up. The case report iscomplimented with a review of the literature.