Giant Congenital Melanocytic Nevus in a Newborn with Congenital Syphilis: A Case Report

Abstract

Introduction: Congenital melanocytic nevi (CMN) are cutaneous hamartomas characterized by abnormal proliferation of melanocytes. Their classification depends on size: small (<1.5 cm), medium (1.5–10 cm), large (11–20 cm), and giant (>20 cm). Giant CMN are associated with significant complications, including risk of malignant transformation, neurological involvement, and psychological impact on the patient and family.

Case Report: We report the case of a male newborn, product of a controlled pregnancy with a maternal history of treated syphilis. He was born at term with adequate neonatal adaptation. Physical examination revealed a hyperpigmented, hair-covered plaque extending from the posterior cervical region to the

midback, measuring approximately 22 × 20 cm, consistent with a giant CMN of the bolero type. In addition, a 5 cm dorsal protrusion was noted. Magnetic resonance imaging showed a homogeneous solid mass compatible with congenital melanocytic nevus, without spinal cord involvement or abdominal abnormalities. The patient received antibiotic therapy for congenital syphilis and was discharged with scheduled follow-up in pediatrics, pediatric dermatology, and infectious diseases.

Conclusion: Giant CMN require an individualized approach. Multistage surgical excision is the treatment of choice, although alternative therapies may be considered to improve cosmetic appearance and reduce malignancy risk. Neurological evaluation and multidisciplinary follow-up are essential, particularly in lesions located along the spinal axis due to the risk of neurocutaneous melanosis. This case highlights the importance of early diagnosis and comprehensive therapeutic planning to optimize prognosis.