Waldenstrom's Macroglobulinaemia (Lymphoplasmacytoid Lymphoma)
- Waldenstroms Macroglobulinaemia (WM) is a neoplasm of small lymphocytes, plasmacytoid lymphocytes, and plasma cells usually involving lymph nodes, bone marrow, and spleen.
- These cells produce a monoclonal IgM protein leading to hyperviscosity and/or cryoglobulinaemia in many cases.
- Serum IgM is usually more than 30 g/L. Urinary light chain excretion may occur and the serum free light chain ratio is abnormal.
- Patients often present with fatigue and lymphadenopathy, and about 10% will have an associated neuropathy. This possibly reflects a reaction between the monoclonal IgM protein and myelin sheath antigens.
- Immunophenotyping the abnormal cells are sIg+, usually IgM. CD19, 20, 22 and 79a+, CD5, 10 and 23 negative, CD43 weak, CD38+.
- MYD88 gene is mutated in 90% of cases. t(9;14) and rearrangement of PAX-5 gene are present in up to 50% of cases.
Note: IgM MGUS may precede overt Waldenstroms Macroglobulinaemia. IgM in this situation is < 30 g/L.
Management
- This should not be offered because of any particular IgM level. Treatment is recommended for progressive symptoms or signs secondary to Waldenstroms macroglobulinaemia. Fatigue, hyperviscosity, cryoglobulinaemia related symptoms, progressive lymphadenopathy and/or hepatosplenomegaly and progressive cytopenias are all indications for some form of treatment.
- Initial treatment options could include Rituximab and bendamustine, or rituximab cyclophosphamide and dexamethasone.
- For a review of the treatment of relapsed and refractory patients with Waldenstroms macroglobulinaemia, see Dimopoulos MA, Kastritis E. How I treat Waldenström macroglobulinemia. Blood 2019;134(23):2022-2035. DOI: 10.1182/blood.2019000725.
Topic Code: 5964
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