Neurocutaneous Melanosis: A Diagnostic Challenge

Neurocutaneous Melanosis (NCM) is a rare congenital syndrome presenting as a large or multiple congenital melanocytic nevi and benign or malignant pigment cell tumours of the leptomeninges. The syndrome is defined as an error in the morphogenesis of the embryonal neuroectoderm. It is one of the rare phakomatoses seen in childhood and shows variable presentations. The authors hereby presents a case report of a 15-year-old male patient with NCM, who presented with recurrent episodes of seizures and difficulty in walking. On physical examination, the patient had multiple congenital cutaneous nevi on the trunk, back, and hands. Immunohistochemistry (IHC) with Haematoxylin & Eosin (H&E) staining confirmed the diagnosis of leptomeningeal diffuse melanocytosis was made.