LAUSR

A 21-year-old man with headache, vomiting, and limb weakness presented to the clinic 2 years ago. An examination showed paresthesia and weakness in left upper and lower limbs. An examination of the brain MRI demonstrated a large space-occupying lesion with ring enhancement and compression of the right fronto-tempo-parietal lobes (Figure 1, A and B). The patient underwent surgery for a presumed glioblastoma. Pathologic examination revealed primary central vasculitis (PCNSV) without neoplasm (Figure 2). His screening workup for systemic vasculitis showed negative results. Symptoms improved after a corticosteroid taper. After stopping immunosuppressive therapy for 1 year, new lesions were found again in the right frontotemporal lobe (Figure 1, C and D). Corticosteroids and mycophenolate mofetil were given, and the patient's symptoms significantly improved and lesions on MRI had subsided significantly (Figure 1, E and F). MRI findings of PCNSV frequently present as nonspecific white matter lesions.1 It can mimic glioblastoma,2 CNS lymphoma, and tumefactive multiple sclerosis.1