Vasculitis associated with haematologic malignancies

Purpose of review This review examines the complex bidirectional relationship between vasculitis and hematologic malignancies, highlighting the importance of meticulous diagnostic assessment. Recent findings Vasculitis may emerge in the setting of hematologic malignancies via mechanisms such as paraneoplastic inflammation, immune dysregulation, drug exposure, and clonal hematopoiesis. Myeloid neoplasms – especially myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML) – show a stronger association than lymphoid malignancies, with cutaneous small vessel vasculitis being the most common subtype. VEXAS syndrome exemplifies the overlap between autoinflammation and hematologic disease, often presenting with vasculitic features and macrocytic anemia. In lymphoproliferative disorders and plasma cell dyscrasias, vasculitis may precede, mimic, or complicate the malignancy. Entities such as intravascular lymphoma, angioimmunoblastic T-cell lymphoma, and monoclonal gammopathies – including MGUS and multiple myeloma – can manifest with vasculitic symptoms, requiring histopathologic and molecular evaluation. Emerging concepts like monoclonal gammopathy of cutaneous and rheumatologic significance highlight the need for interdisciplinary care. Drug-induced vasculitis, particularly from immunomodulatory agents and biologics, adds diagnostic complexity. Atypical features – such as unexplained cytopenias, dual autoantibody positivity, or poor response to immunosuppression – should prompt evaluation for underlying hematologic disease. Conversely, vasculitis may signal complications in patients with known hematologic disorders. Summary Early suspicion of vasculitis associated with hematologic malignancies and accurate diagnosis are important in guiding therapeutic approaches.