Vasculitis in hairy cell leukemia: Review of literature and consideration of possible pathogenic mechanisms

Systemic vasculitis is an unusual but recently recognized complication of hairy cell leukemia. We studied this relationship further in an attempt to better understand pathogenetic mechanisms of vasculitis. We examined the records of 129 cases of hairy cell leukemia seen at the Mayo Clinic between 1976 and 1983, and identified 2 cases with evidence of systemic vasculitis. The first of these cases is discussed in detail. Immunologic studies were performed but we were unable to demonstrate the presence of shared antigen on hairy cells and endothelial cells. The literature is reviewed and reports of this association are summarized. Possible mechanisms of vascular injury are discussed.