Congenital Melanocytic Hairy Nevi in a Child from North-Western Nigeria

Aim: To present the first report of a large congenital melanocytic nevus with satellite nevi in an apparently healthy child from Sokoto, North-Western Nigeria.

Presentation of Case: A three year old girl was brought to the paediatric out-patient clinic of Paediatrics department of Usmanu Danfodiyo University Teaching Hospital (UDUTH) Sokoto with complaints of darkened skin colour on the left side of the face and scalp, the left arm, lower back, buttocks, and thighs, and excessive hair growth over the same side of the face since birth. There were no neurological symptoms Physical examination findings revealed a well-nourished, not ill looking child. She had a hyper pigmented patch on the left side of the face extending from the lower jaw to the scalp, measuring 21 cm in its longest length, with hypertrichosis on the same site, and two distinct, firm, painless nodular lesions on the left temporal region measuring 3 mm and 4mm respectively. On the lower one-third of the left arm was a hairy, velvety area of hyperpigmentation measuring 2X3 cm in diameter. Other affected sites were the lower back, the gluteal region and the thighs. Her neurologic and other systemic examinations were normal. A diagnosis of large congenital facial melanocytic hairy nevus with multiple satellite nevi was made.

Discussion: Congenital melanocytic nevi are benign proliferations of melanocytic cells said to be present at birth or in the first two years of life. Large lesions are rare, they measure 20 cm or more and are said to occur more commonly on the trunk and thighs. The exact pathogenesis of congenital melanocytic nevi is yet, unknown. It is thought to occur as a result of a morphological error in the neuroectoderm during embryogenesis. Treatment of patients with large congenital melanocytic nevus may include surgical or non-surgical procedures as well as psychological interventions. Large lesions, multiple satellite lesions or paravertebral and axial locations are sometimes associated with the risk of neurological complications and malignant transformation.

Conclusion: Large congenital melanocytic nevi are uncommon skin lesions that can occur in apparently healthy children. Individualization of the patients with regards to treatment options and long term monitoring are imperative.