Nevus comedonicus: A case report with the histological findings and brief review of the literature.

introductionNevus comedonicus (NC) is a rare cutaneous disorder thought to be caused by hamartomatous pilosebaceous tissue proliferation that was first described in 1895. Clinically NC appears as a group of elevated follicular openings often linearly arrayed, giving the appearance of comedones. NC usually manifests at birth but can also present later during adolescence and rarely in adulthood. CASE PRESENTATION: A 21-year-old medically healthy single male presented with right-sided chest black papules in comedo distribution with areas of superficial ulcerations and suppurations in periareolar distribution since the age of 16. Histopathological examination showed dilated follicular ostia filled with keratin plug, devoid of the hair shaft, and lined by stratified squamous epithelium with compact hyperkeratosis, focal parakeratosis, and patchy atrophy and acanthosis. CLINICAL DISCUSSION: Nevus comedonicus often responds effectively to conservative treatment, however some cases need surgery intervention. The patient failed conservative medical and topical treatment, and he was treated by surgical-wide local excision and primary closure of the affected skin with free nipple grafting.

conclusionNevus comedonicus (NC) is a rare cutaneous pathology secondary to pilosebaceous apparatus developmental defect that usually manifests at birth and can affect any area of skin; they typically manifest as black papules in comedo distribution. They can present as an isolated cutaneous pathology or as a component of nevus comedonicus syndrome. Different therapeutic approaches were described, including topical retinoids, keratolytic agents, oral retinoids, antibiotic therapy, manual extraction of comedos, dermabrasion, and surgical resection of the lesion.