Neurocutaneous Melanosis in Children and Adults With Clinical, Radiological, and Pathogenic Evaluation: Case Report and Review of the Literature.

Neurocutaneous melanosis (NCM) is a rare, non-inherited disease characterized by the presence of giant congenital melanocytic nevi (CMN) or multiple CMN, and it is often associated with meningeal melanosis or meningeal melanoma. This report presents two representative cases of NCM: one involving a 6-year-old female patient and the other involving a 30-year-old male patient. Both patients were born with severe CMN, including lesions on their hairy trunk, and later acquired malignant leptomeningeal involvement. We evaluated the clinical, radiological, and pathological features of cutaneous and central nervous system (CNS) lesions in these two patients, emphasizing their similarities and distinct manifestations. The research analysis highlights that individualized monitoring and related intervention strategies may improve the clinical prognosis of patients with this uncommon and potentially fatal disease through the process of early identification of high-risk features associated with malignant transformation.