Paraneoplastic Immunoglobulin A Vasculitis With Rapidly Progressive Glomerulonephritis in a Patient With Metastatic Meningioma: Case Report and Literature Review

Immunoglobulin A vasculitis with renal involvement (IgAVN) is an immune complex-mediated glomerulonephritis characterized by mesangial deposition of IgA1-containing immune complexes. Although malignancy-associated vasculitis is recognized, paraneoplastic IgAVN remains rare, and its clinical patterns and optimal management strategies are not well defined. We present an illustrative case of relapsing crescentic IgAVN temporally associated with metastatic meningioma and contextualize this presentation through a focused review of published cases from 2000 to 2025. A total of 21 adult cases of IgA vasculitis with renal involvement have been reported, predominantly affecting men. The reported malignancies included hematologic, gastrointestinal, pulmonary, renal, and genitourinary cancers. In most cases, vasculitis and malignancy were diagnosed concurrently or within a short temporal window, supporting a potential paraneoplastic relationship. Renal manifestations ranged from hematuria and proteinuria to rapidly progressive glomerulonephritis. The outcomes and prognosis varied for these patients: complete remission occurred in 43% of cases, partial remission in 24%, and progression in 24%. Our review suggests that combined malignancy-directed therapy and corticosteroids may be associated with more favorable renal outcomes compared with immunosuppression alone. Proposed mechanisms include tumor antigen-driven immune complex formation, dysregulated glycosylation of IgA1, and complement activation. However, mechanistic data remain limited. Recognition of this association is clinically important, as adult-onset, relapsing, or unusually aggressive IgAVN should prompt evaluation for underlying malignancy or cancer progression. Further study is needed to clarify pathophysiologic pathways and to guide evidence-based management in this rare but clinically significant entity.