Waldenström macroglobulinemia: 2015 update on diagnosis, risk stratification, and management

Disease Overview: Waldenström macroglobulinemia (WM) is a lymphoplasmacytic lymphoma with immunoglobulin M (IgM) monoclonal protein. Clinical features include anemia, thrombocytopenia, hepatosplenomegaly, lymphadenopathy, and rarely hyperviscosity. Diagnosis: Presence of IgM monoclonal protein associated with ≥10% clonal lymphoplasmacytic cells in bone marrow confirms the diagnosis. The L265P mutation in MYD88 is detectable in more than 90% of patients. Risk Stratification: Age, hemoglobin level, platelet count, β₂ microglobulin, and monoclonal IgM concentrations are characteristics required for prognosis. Risk-Adapted Therapy: Not all patients who fulfill WM criteria require therapy; these patients can be observed until symptoms develop. Rituximab-based therapy is used in virtually all US patients with WM and can be combined with alkylating agent or purine nucleoside analog (or both). The preferred Mayo Clinic nonstudy therapeutic induction is rituximab, cyclophosphamide, and dexamethasone. Future stem cell transplantation should be considered in induction therapy selection. Management of Refractory Disease: Bortezomib, thalidomide, everolimus, ibrutinib, carfilzomib, lenalidomide, and bendamustine have all been shown to have activity in WM. Given WM's natural history, reduction of complications will be a priority for future treatment trials.