Melanocytic lesions are diffuse or circumscribed, benign, or malignant tumors arising from melanocytes of the leptomeninges (Jellinger et al. 2000).
- diffuse melanocytosis (diffuse melanosis) and
- neurocutaneous melanosis,
- malignant melanoma. Intermediate or mixed cases may occur.
Imaging and Location
Melanocytoma accounts for 0.06–0.1% of brain tumors; the other melanocytic lesions are rarer. These lesions typically occur in the fifth decade of life with a femaleto-male ratio of 2:1. Diffuse melanocytosis involves the supratentorial and infratentorial leptomeninges; melanocytomas occur as solid masses in the cranial and spinal compartments.
On both CT and MRI, the features of melanocytic lesions are similar to those of meningiomas
- M.F. Reiser, W. Semmler, H. Hricak (Eds.) "Magnetic Resonance Tomography", Springer 2008