Neurocutaneous Melanocytosis Registry

This registry is collecting information about patients with Neurocutaneous Melanocytosis (NCM) — a rare condition where abnormal pigment cells grow on the skin and/or in the brain and spinal cord — to better understand the disease and support future research. **You may be eligible if...** - You have a large congenital melanocytic nevus (LCMN) — a large dark birthmark — which may or may not have satellite lesions or abnormal hair growth - OR you have confirmed melanocyte overgrowth in the central nervous system (brain or spinal cord), even without a skin birthmark - Patients of any age can be included, including children - Deceased patients may also be included (with guardian consent, contacted at least 6 months after death) **You may NOT be eligible if...** - You do not have a large congenital melanocytic nevus or confirmed CNS melanocytosis - A parent or legal guardian is not available to provide consent for minor patients Talk to your doctor to see if this trial is right for you.