Vasculitis associated with malignancy.
A large variety of vasculopathic syndromes are uncommonly associated with malignancies. Vasculitis is usually manifested by skin lesions and is generally associated with hematologic malignancies rather than solid tumors. Evidence of autoantibodies, immune complexes, and complement consumption is typically absent. Myelodysplastic syndromes can be confidently linked to vasculitis on the basis of recent literature. The temporal relationship of malignancy to vasculitis development is variable except that vasculitis generally follows the discovery of hairy cell leukemia and splenectomy. Vasculitis may occasionally be a complication of chemotherapy, radiation therapy, and bone marrow transplantation. Occasionally, malignant disorders may mimic vasculitic syndromes. The etiopathogenesis of vasculitis in patients with malignant disorders is unknown. The recent literature on vasculitis and malignancy addresses predominantly case reports and small patient cohorts and identifies clinical characteristics rather than pathogenic mechanisms.