[Waldenström macroglobulinemia associated with cutaneous lesions and type I cryoglobulinemia].

Waldenström macroglobulinemia is a blood dyscrasia characterized by monoclonal proliferation of B cells in the bone marrow, lymph nodes, and spleen. Patients with this disease show elevated serum levels and tissue deposition of monoclonal immunoglobulin (Ig) M produced by these aberrant cells. We present the case of a patient with Waldenström macroglobulinemia who suffered cutaneous lesions resulting from deposition of k light chains of IgM and clinical manifestations secondary to associated type I cryoglobulinemia. We discuss the different pathological cutaneous processes caused by IgM in Waldenström macroglobulinemia.