Multifocal progressive neurological disorder caused by neoplastic angioendotheliosis.

The case of a 46-year-old woman who suffered a multifocal neurological illness, which rapidly progressed to dementia, is reported; the clinical signs were suggestive of multiple sclerosis. At necropsy, polyfocal cerebral white-matter lesions, associated with intravascular plugs of neoplastic cells which appeared to arise from the vascular endothelium, were found. The findings were typical of a rare form of malignant disease of the vascular endothelium known as neoplastic angioendotheliosis, which shows a striking predilection for the central nervous system.