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

Genome-wide profiling of 5-hydroxymethylcytosines in circulating cell-free DNA reveals population-specific pathways in the development of multiple myeloma

Multiple myeloma (MM) and its precursors monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma (SMM) are 2–3 times more common in African Americans (AA) than European Americans (EA). Although epigenetic changes are well recognized in the context of myeloma cell biology, the contribution of 5-hydroxymethylcytosines (5hmC) to racial disparities in MM is unknown. Using the 5hmC-Seal and next-generation sequencing, we profiled genome-wide 5hmC in circulating cell-free DNA (cfDNA) from 342 newly diagnosed patients with MM (n = 294), SMM (n = 18), and MGUS (n = 30). We compared differential 5hmC modifications between MM and its precursors among 227 EA and 115 AA patients. The captured 5hmC modifications in cfDNA were found to be enriched in B-cell and T-cell-derived histone modifications marking enhancers. Of the top 500 gene bodies with differential 5hmC levels between MM and SMM/MGUS, the majority (94.8%) were distinct between EA and AA and enriched with population-specific pathways, including amino acid metabolism in AA and mainly cancer-related signaling pathways in EA. These findings improved our understanding of the epigenetic contribution to racial disparities in MM and suggest epigenetic pathways that could be exploited as novel preventive strategies in high-risk populations.

IgM myeloma: A multicenter retrospective study of 134 patients

IgM myeloma is a rare hematologic malignancy for which the clinicopathological features and patient outcomes have not been extensively studied. We carried out a multicenter retrospective study in patients with diagnosis of IgM myeloma defined by >10% marrow involvement by monoclonal plasma cells, presence of an IgM monoclonal paraproteinemia of any size, and anemia, renal dysfunction, hypercalcemia, lytic lesions and/or t(11;14) identified by FISH. A total of 134 patients from 20 centers were included in this analysis. The median age at diagnosis was 65.5 years with a male predominance (68%). Anemia, renal dysfunction, elevated calcium and skeletal lytic lesions were found in 37, 43, 19, and 70%, respectively. The median serum IgM level was 2,895 mg dL^-1 with 19% of patients presenting with levels >6,000 mg dL^-1 . International Staging System (ISS) stages 1, 2, and 3 were seen in 40 (33%), 54 (44%), and 29 (24%) of patients, respectively. The malignant cells expressed CD20 (58%) and cyclin D1 (67%), and t(11;14) was the most common cytogenetic finding (39%). The median overall survival (OS) was 61 months. Higher ISS score was associated with worse survival (P = 0.02). Patients with IgM myeloma present with similar characteristics and outcomes as patients with more common myeloma subtypes.

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

As IgM multiple myeloma is a rare poorly characterised disease entity; there is only limited published data on its clinical, microscopic and immunophenotypic features. We report a 72-year-old man misdiagnosed as Waldenström's macroglobulinemia. Also the diagnosis was further complicated by coexisting chronic lymphocytic leukaemia. Following confirmation of IgM myeloma, in view of the patient's deteriorating clinical condition; he was entered into the UK Medical Research Council Myeloma IX trial where he had partial response to chemotherapy. This case highlights the value of detailed immunophenotypic evaluation when clinical and morphological markers are equivocal.

IgM multiple myeloma presenting with spinal cord compression caused by a plasmacytoma: A case report

Background

IgM multiple myeloma is rare disorder, which has clinical, laboratory and radiological manifestations that are consistent with both multiple myeloma and Waldenstrom's macroglobulinaemia.

Case presentation

An 83 years Welsh lady presented with clinical and radiological features consistent with spinal cord compression. Further investigations confirmed the diagnosis of IgM multiple myeloma. Following localized radiotherapy and five courses of melphalan and prednisolone, the patient achieved partial remission of her myeloma. Later on, the patient had disease progression in the form of rising serum IgM level and the development of multiple plasmacytomas. She was treated with thalidomide, cyclophosphamide, dexamethasone and radiotherapy, which resulted in the control of her disease for one year. To our knowledge, this is the second case of IgM myeloma presenting with a plasmacytoma and the first case of IgM myeloma presenting with cord compression caused by plasmacytomas.

Conclusion

Unlike other types of multiple myeloma IgM myeloma is rarely complicated by plasmacytomas. However, spinal cord compression caused by plasmacytomas in this type of myeloma is extremely rare. Nevertheless, the same lines of management, e.g. cytotoxic chemotherapy and local radiotherapy that are applied to other types of myeloma can be successfully utilized.

Performance of the Sebia CAPILLARYS 2 for detection and immunotyping of serum monoclonal paraproteins

We evaluated the performance of the CAPILLARYS 2 (Sebia, Norcross, GA) capillary electrophoresis system for detection and identification of monoclonal proteins in serum samples. We analyzed 104 serum specimens by Sebia Hydragel serum protein electrophoresis (agarose gel electrophoresis [AGE]/immunofixation electrophoresis [IFE]) and CAPILLARYS 2 capillary zone electrophoresis (CZE)/immunosubtraction. AGE and CZE had sensitivities of 90% and 81%, respectively, based on IFE as the "gold standard," and all bands detected were confirmed by IFE (100% specificity). AGE and CZE had an overall agreement of 91% on serum protein electrophoresis. In the population tested, IgG was detected in 29% of samples by IFE and 30% using immunosubtraction. Similarly IgA was detected in 9% of cases by IFE and 8% by immunosubtraction. IgM and light chains were detected in 6% and 3% of cases, respectively, by IFE, whereas CZE/immunosubtraction did not detect any IgM or light chains. In our hands, AGE and CZE had the same specificity for detection of monoclonal proteins; however, CZE/immunosubtraction seems to be less sensitive than IFE for the detection of IgM and, possibly, serum light chains.

IgM multiple myeloma: report of four cases and review of the literature

The differential diagnosis between multiple myeloma (MM) and Waldenström's macroglobulinemia (WM) is generally well defined. Consistent with a diagnosis of MM is the presence of a non-IgM monoclonal gammopathy associated to multiple osteolytic lesions and plasma cell infiltration of the bone marrow. Characteristic of WM is the presence of an IgM monoclonal gammopathy associated to lymphoadenopathy, hepatosplenomegaly, anemia and hyperviscosity syndrome in the presence of a monoclonal lymphoplasmacytoid proliferation in the bone marrow. Nonetheless, few cases of IgM myeloma have been reported that display clinico-pathologic features intermediate between MM and WM. Here, this study describes four of 317 (1.2%) patients with an IgM monoclonal gammopathy in whom the morphologic and clinical features were consistent with a diagnosis of IgM myeloma.

Immunoglobulin M Myeloma: Evaluation of Molecular Features and Cytokine Expression

Immunoglobulin (Ig) M myeloma is a distinct entity with features of multiple myeloma (MM) and Waldenstrom's macroglobulinemia (WM). The malignant cells in IgM myeloma have a distinctive chromosomal translocation that differentiates them from WM. These cells are postgerminal-center in origin with isotype-switch transcripts. They appear to be arrested at a point of maturation between that of WM and MM. Preliminary data indicate that a pattern of osteoclast-activating factor and osteoprotegerin expression similar to that observed in classic MM is present in IgM myeloma. Additional studies on patients with this rare tumor may provide further insight into the pathogenesis of bone disease in plasma cell dyscrasias.