A rare cause of seizure masquerading as neoplasm.

The authors report the case of a young man with no significant medical history who presented with new-onset seizure and mass-like lesions isolated to the left cerebral hemisphere relating to malignancy. Biopsy revealed findings consistent with angiitis and investigations for secondary causes of angiitis was negative. The diagnosis of primary angiitis of the central nervous system was made and the patient has responded well to treatment.