A number of pathological entities affecting the central nervous system contain melanin. They can be divided into primary and secondary melanocytic lesions.
Primary
Primary melanocytic lesions arise from melanin-containing neural crest cells which are located in the leptomeninges. They include 1-3:
- diffuse melanosis (seen in neurocutaneous melanosis)
- melanocytoma
- primary meningeal malignant melanoma
In addition to these primary lesions which arise from melanin-containing cells, a number of other tumors of the CNS can rarely contain melanin. These include 3:
- melanotic meningioma
- melanotic schwannoma
- melanotic medulloblastoma
- melanotic differentiation of low-grade gliomas
- craniopharyngiomas may rarely contain melanin
- melanotic differentiation of a gliosarcoma (single case report 4)
Secondary
Secondary melanocytic lesions are far more common and represent metastatic malignant melanoma.