| umls-concept:C1266112 | skos:definition | NCI: A diffuse or multifocal proliferation of uniform nevoid polygonal cells in the leptomeninges. Cells may spread into the Virchow-Robin spaces without frank invasion of the brain. Diffuse melanocytosis carries a poor prognosis even in the absence of histologic malignancy. (WHO) | lld:umls |
