LAUSR

The dermatologic manifestations of Waldenstrom macroglobulinemia (WM) are typically categorized as disease specific or non–disease specific.1 Non–disease-specific findings are related to hyperviscosity or cryoglobulinemia, including mucosal bleeding, purpura, livedo reticularis, and Raynaud phenomenon. Two rare types of specific skin findings have been identified: cutaneous infiltrates of mature B-cell neoplasms, specifically heavy-chain or malignant immunoproliferative diseases, and deposits of monoclonal immunoglobulin (Ig) M, referred to as cutaneous macroglobulinosis (CM). Although classically described in patients with WM, cutaneous deposition could develop in any condition associated with IgM paraproteinemia. First documented in 1978 by Tichenor et al,2 CM is remarkable for its association with underlying plasma cell dyscrasias and its ability to mimic other depositional disorders. Here, we report a patient initially diagnosed with lymphoplasmacytic lymphoma (LPL) whose subsequent development of neuropathy and hyperviscosity syndrome due to elevated serum IgM led to a diagnosis of WM. The patient then developed a disseminated cutaneous presentation of CM, with minimal residual WM disease and cryoglobulinemia.