Primary Angiitis of Central Nervous System-Tumor-Like Mass Lesions: Report of Six Biopsy Confirmed Cases

Tumor-like mass lesion is a rare subtype of primary angiitis of the central nervous system (ML-PACNS). This report describes six patients of histologically verified ML-PACNS. The mean age was 44.5 years (range 25–68) and four were males. Presenting symptoms headache (5), focal neurologic deficits (5), and seizures (4). On magnetic resonance imaging (MRI) the lesion was unifocal in two and multifocal in four patients. Consistent radiological findings were mass lesions with heterointense internal morphology with areas of diffusion restriction (DWI), and variable post-contrast enhancement. Pathologically vasculitis was classified as: Granulomatous in one, necrotizing in two and lymphocytic in three. There were two deaths. In conclusion patients with ML-PACNS are likely to be younger and more likely to present with seizures. MRI lesions with hetrointense internal morphology with areas of DWI was a consistent finding and may be a clue for the diagnosis of ML-PACNS.