Benign focal cerebral vasculitis: case report.

We report a 47-year-old man who presented with partial seizures complicating focal cerebral vasculitis of the right temporal lobe. Excisional biopsy of the mass lesion revealed fibrinoid necrosis of small vessels. These vessels were infiltrated by neutrophils, eosinophils, lymphocytes, and plasma cells. Despite extensive evaluation, no etiology was apparent for the vasculitis. No immunosuppressive agents were administered, and 4 1/2 years after the diagnosis, he remains healthy except for an incongruous left homonymous hemianopia. Follow-up cranial magnetic resonance images revealed only postoperative changes. This case demonstrates that focal lesions and a benign course may represent one end of the spectrum of primary angiitis of the central nervous system.