IgM Multiple Myeloma: A Rare Clinical Entity and Diagnostic Dilemma

Abstract

IgM multiple myeloma is a rare disease that shares many common features with Waldenström macroglobulinemia and lymphoplasmacytic lymphoma. It has been described in the literature as having unique diagnostic findings that separate it from the more common IgG and IgA myelomas. It is important for physicians to be able to differentiate between IgM multiple myeloma, Waldenström macroglobulinemia and lymphoplasmacytic lymphoma as their treatments vastly differ. This case report describes the clinical presentation of a patient with IgM lambda multiple myeloma and highlights the pathologic and clinical findings that are specific to this rare entity. We aim to provide further evidence for the previously reported diagnostic criteria for IgM multiple myeloma.