Annular leukocytoclastic vasculitis associated with monoclonal gammopathy of unknown significance.

Leukocytoclastic vasculitis is a condition characterized by necrotizing neutrophilic inflammation of small dermal blood vessels usually resulting in palpable purpuric lesions. Leukocytoclastic vasculitis may be secondary to a variety of medications and underlying disease processes, including infections, connective tissue disorders, and malignancies. We describe a patient with a monoclonal gammopathy of unknown significance in whom leukocytoclastic vasculitis developed, manifested by a few prominent annular plaques on the lower extremity. The rare association between monoclonal gammopathy of unknown significance and leukocytoclastic vasculitis as well as the unusual annular presentation of the disease in this patient is discussed, and the relevant literature is reviewed.