Leukemic vasculitis: a feature of leukemia cutis in some patients.

Cutaneous involvement is common in certain subtypes of acute leukemia and may be a reflection of a capacity of these tumors for tissue infiltration. We have recently noted that leukemia cutis can be accompanied by vasculitis in a subset of patients. We describe six cases of such leukemic vasculitis with findings ranging from mild microvascular injury to necrotizing arteritis. All cases were seen in patients with acute leukemia with myelomonocytic or monocytic features. In one patient, cutaneous leukemic vasculitis represented the initial manifestation of leukemia. In most cases, leukemic infiltration of the dermal blood vessels was the predominant pattern of involvement with minimal dermal infiltration. Vascular injury seemed to be mediated by leukemic blasts and not by reactive inflammatory cells. We propose the term leukemic vasculitis to describe such lesions.