Tumor-like Presentation of Cerebral Vasculitis in a Patient With Systemic Lupus Erythematosus: A Biopsy-confirmed Case.

Central nervous system (CNS) manifestations of systemic lupus erythematosus (SLE) are diverse and often difficult to distinguish from SLE-unrelated events. CNS vasculitis is a rare manifestation, which is seen in less than 10% of post-mortem studies, and lesions with multifocal cerebral cortical microinfarcts associated with small-vessel vasculitis are the predominant feature. However, CNS vasculitis presenting as a tumor-like mass lesion in SLE has rarely been reported. Herein, we report a case of cerebral vasculitis mimicking a brain tumor in a 39-year-old female with SLE. A biopsy of the brain mass revealed fibrinoid necrosis and leukocytoclastic vasculitis. The neurological deficits and systemic symptoms improved after treatment with corticosteroids and immunosuppressive agents. To the best of our knowledge, there are no reports of biopsy-proven cerebral vasculitis presenting as a brain mass in patients with SLE in Korea.