Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is a rare indolent B-cell lymphoma that most commonly occurs in older white men.

The pathophysiologic hallmark is monoclonal immunoglobulin M (IgM) production by malignant lymphoplasmacytic cells that infiltrate the bone marrow and visceral organs.

Diagnosis is most often made following an incidental finding of an IgM monoclonal protein (paraprotein) on a blood test.

Anemia (due to marrow infiltration), fatigue, and anorexia are the most common clinical features. Lymphadenopathy, splenomegaly, and hyperviscosity (which can lead to bleeding, thrombosis, retinopathy, and neurologic symptoms) require urgent treatment.

Treatment includes observation (for asymptomatic patients), plasmapheresis, chemotherapy, and targeted therapies (e.g., Bruton tyrosine kinase inhibitor). A clinical trial should be considered where possible as there is no standard of care.

WM is incurable but is associated with long survival, particularly with use of targeted therapies. Transformation to aggressive high-grade lymphoma can occur.

WM (also referred to as lymphoplasmacytic lymphoma [LPL]) is an indolent B-cell lymphoma in which malignant lymphoplasmacytic cells infiltrate bone marrow and visceral organs, and hypersecrete an IgM monoclonal protein.

Clinical manifestations are most commonly related to bone marrow infiltration by malignant lymphoplasmacytic cells (e.g., anemia, thrombocytopenia, pancytopenia).

Less common clinical manifestations are related to organ infiltration (e.g., splenomegaly, hepatomegaly, and lymphadenopathy) and monoclonal IgM production by malignant lymphoplasmacytic cells (e.g., hyperviscosity syndrome, peripheral neuropathy, cryoglobulinemia, cold agglutinin hemolytic anemia, bleeding from the nose and gums, purpura, thrombosis [e.g., stroke, angina, myocardial infarction, pulmonary embolism, deep vein thrombosis], and kidney disease).

In contrast with multiple myeloma, bone lesions are not a feature of WM.