GP67 A Case Report of an Infant with Giant Congenital Melanocytes Naevus with Neurocutaneous Melanosis

Background A term infant with features of Giant Congenital Melanocytic Naevus (GCMN) with Neurocutaneous Melanosis (NCM). Case report A term, female infant, with an uncomplicated antenatal course, of non-consanguineous parents, was noted at birth to have extensive pigmentation of the body. Examination demonstrated hyperpigmented, rugged, plaque-like lesions in a bathing suit distribution. Within the pigmented naevus were irregularly shape macule, papules, and plaques of various colours. Multiple pigmented satellite lesions of size 4–5 cm were present over the body, head, face and extremities. Tufts of coarse hair were present over the satellite lesions, with finer hair covering the abdominal areas of pigmentation. Three nodular lesions were present in the perianal region. Areas of excoriation were noted on the flank areas. No other physical abnormalities were present. Neurological examination was unremarkable. MRI examination revealed extensive intracranial melanocytic infiltrate, confirming a diagnosis of CGMN with NCM. Discussion CGMN is an extremely rare condition with incidence estimated at 1/500000 births. Lesions are caused by genetic mutations which lead to defective proliferation, differentiation and migration of melanoblasts. Risk of transformation of GCMN to malignant melanoma varies between 0 and 3.8%, with 80% of this number symptomatic by the age of seven. CNN originates between the 5th-24th week of gestation and arises from gain of function mutations in either BRAF or NRAS. The protooncogenes c-met and c-kit have also been demonstrated to play a role in the formation of CMN. CMN are predominantly caused by sporadic de novo mutations. Neurocutaneous melanosis is a rare complication of CMN with just over 100 cases reported. Most patients with NCM are asymptomatic t birth with sequelae appearing later in development. Treatment of GCMN is both symptomatic and palliative, with surgical techniques including serial resection, excision and grafting and the use of tissue expanders. Non-excisional techniques include dermabrasion, laser ablation and curettage. References Das SK, Amarendra N, Monalisa S. Giant Congenital Melanocytic Nevi. J Clin Diagn Res: 2013 Jan; 7(1): 154–155 Viana ACL, Gontijo B, Bittencourt FG. Giant Congenital Melanocytic Nevus. An Bras Dermatol. 2013 NOV-Dec 88(6) Meshram GG, Kaur N, Hura KS. Giant Melanocytic Nevi: An Update and Emerging Therapies. Case Rep Dermatol 2018; 10:24 Rai S, Kalakoti P, Syed MMA, Thacker PJ, Jain R, Kalra G. An unusual case of congenital melanocytes nevus presenting as neurocutaneous melanoma coexisting with Tuberous Sclerosis complex. A case report. Journal of Medical Case Reports 2011 5:267