IgM Myeloma, a Distinct Entity in the Spectrum of B-cell Neoplasia

Abstract

The distinction between multiple myeloma and Waldenström's macroglobulinemia can usually be made on the basis of clinical, histologic, and immunologic findings. However, some patients have features of both diseases. Two patients who had IgM monoclonal gammopathies and plasma cell neoplasia are presented. Both had bone lesions, monoclonal IgMk, and bone marrow infiltration with plasma cells. The presence of plasma cells was verified by electron microscopy. Immunoperoxidase studies in both cases showed positive staining with mu and kappa antisera only, suggesting that these plasma cells were the source of the IgMk protein. Using the criteria of monoclonal IgM, plasma cell neoplasia, and bone lesions, 28 similar cases were found. The analysis of clinical data revealed an increased incidence of lytic bone lesions, decreased IgG and IgA, renal failure, hypercalcemia, and Bence-Jones proteinuria, as are commonly seen in multiple myeloma. It also demonstrated an increased incidence of hyperviscosity symptoms, lymphadenopathy, hepatosplenomegaly, and mucous membrane bleeding, as are often seen in Waldenström's macroglobulinemia. Other common findings were anemia and plasma cell leukemia. These data suggest that, although rare, IgM myeloma should be considered a distinct clinical entity in the spectrum of B-cell malignancies with characteristics of both multiple myeloma and Waldenström's macroglobulinemia.

Clinical characteristics and factors predicting evolution of asymptomatic IgM monoclonal gammopathies and IgM-related disorders

“…11 The presence of cytopenias was shown to predict poor survival in overt WM, [2][3][4][5]8,27 and low Hb levels correlated with poor outcome also in asymptomatic disease. 2,3,19,21,24,28 In our series, anaemia strongly correlated with progression of aIgM-MG, significantly lower Hb levels being detected in sWM than in IgM-MGUS. BM infiltration, hypersplenism, and hyperviscosity-related blood dilution are involved in the pathogenesis of anaemia in overt WM.…”

“…IgM multiple myeloma (MM), amyloidosis, non-Hodgkin's lymphoma (NHL), and chronic lymphocytic leukemia (CLL) were diagnosed as previously described. [19][20][21] Laboratory and clinical studies…”

IgM multiple myeloma: a diagnostic challenge in a patient with coexisting chronic lymphocytic leukaemia

“…The majority of myelomas secrete IgG or IgA paraproteins or free light chains: true IgM MM is rare and represents a poorly characterised entity which accounts for less than 0.5% of all cases [1] IgM paraproteins are much more frequently associated with other clonal B-cell disorders with WM being by far the most common example [2]. Although IgM myeloma accounts for less than 0.2% of IgM paraproteins [3] it does appear to represent a distinct clinical entity [4].…”

IgM myeloma and Waldenstrom's macroglobulinemia: a distinct clinical feature, histology, immunophenotype, and chromosomal abnormality

“…, 1998). Cases of IgM myeloma have been described with clinico‐pathologic features intermediate between those of MM and WM (Zarrabi et al. , 1981).…”