Chapter 36 - Neurocutaneous Melanosis

Abstract

This chapter discusses neurocutaneous melanosis (NCM). NCM, believed to result from a congenital dysplasia of the melanocytes, cells of neuroectodermal origin, is characterized by hairy pigmented nevi located in any skin region with infiltration of the meninges and the CNS by melanin-containing cells. For a definitive diagnosis of NCM, it is essential to do a thorough examination of extensive pathologic specimens or a complete postmortem examination. The disease affects males and females with the same frequency. It is not hereditary and occurs almost exclusively in whites; only rarely is it found in blacks. Many patients have generalized or partial seizures beginning early in life, often before hydrocephalus develops. Other findings associated with NCM are intellectual deterioration and motor deficit. Patients with malignant NCM rarely have lived past the age of 25 years. On the other hand, there are cases of NCM who have had a benign course because the cells involved, being nonmalignant, cause no symptoms.