WALDENSTROM MACROGLOBULINEMIA WITH AN IGM-KAPPA ANTIEPIDERMAL BASEMENT-MEMBRANE ZONE ANTIBODY

Background. -Waldenstrom macroglobulinemia, a lymphoplasmacytoid cell malignant neoplasm associated with a monoclonal IgM paraprotein, has been associated with a number of cutaneous manifestations. On rare occasions, IgM deposits have been demonstrated in the epidermal basement zone of patients with WM. Observations. -We report the case of a patient with Waldenstrom macroglobulinemia and IgM-kappa paraprotein who had development of an eruption of pruritic papules and demonstrated the following unusual immunopathologic findings: (1) deposits of IgM-kappa in the epidermal basement membrane zone of lesional and nonlesional skin; (2) a circulating IgM-kappa antiepidermal basement membrane zone antibody; and (3) binding of this circulating IgM-kappa antiepidermal basement membrane zone antibody to both sides of 1 mol/L sodium chloride split skin. The cutaneous eruption cleared completely with oral psoralen with long-wave UV radiation in the A range (PUVA) therapy. Conclusions. -We present a patient with Waldenstrom macroglobulinemia who had a distinctive papular eruption and immunopathologic findings suggesting that his paraprotein has specificity for the epidermal basement membrane zone.