Combination therapy with cyclophosphamide, rituximab and corticosteroids in order to arrest a rapidly progressive primary CNS vasculitis: a case report with 40-month follow-up remission.

Among primary central nervous system vasculitis variants, rapidly progressive forms pose the greatest challenge, often resulting in fatal outcomes despite conventional immunosuppressive therapies. Treatment recommendations lack standardized guidelines, relying on retrospective studies and expert opinions. Here, we present the case of a 35-year-old male with a rapidly progressive tumefactive primary central nervous system vasculitis refractory to common immunosuppressant drug regimens. We off-label applied the treatment schedule, borrowed from rheumatology, based on combined and concurrent treatment with cyclophosphamide, rituximab and corticosteroids. This approach, previously employed in systemic aggressive ANCAassociated vasculitis, led, also in our patient, to disease stabilization and remission over a 40-months follow-up period. Our case report underscores the potential efficacy of this regimen in refractory PCNSV cases.