Waldenström's Macroglobulinemia (WM) is a proliferative disorder of B-lymphocytes and plasma cells that results in abnormal production of an IgM monoclonal protein (M Protein). It is considered to by a lymphoplasmacytic lymphoma by current classifications (WHO).

WM is a rare disorder, with incidence of ~1500 new cases/year in the United States. It is more common in men and the median age of diagnosis is 64 years.

Typical findings and symptoms include:

• Fatigue (usually due to anemia)
• Lymphoplasmacytic cell infiltration of bone marrow
• Hyperviscosity syndrome
• Organomegally (especially spleen, liver)
• Peripheral neuropathy
• Anemia (often progressive)
• Thrombocytopenia
• Neutropenia (less common)
• Reynauds syndrome
• Hemorrhage (Retinal, oronasal)
• Papilledema
• Mental status changes
• Lymphadenopathy
• Skin changes (most commonly pupura, bullae, etc).

This condition is usually observed and complications treated; with the most common indication for intervention being progressive anemia.

The patient should have the following:

• Serum M protein >3 g/dL
• Lymphocytic infiltration of the bone marrow
• Identification of malignant cells consistent with WM (usually on bone marrow biopsy)

References:

1. Gertz MA, Fonseca R, Rajkumar SV. Waldenströms Macroglobulinemia. Oncologist 2000;5(1):63-7.
2. Kyle RA, Treon SP, Alexanian R, et al. Prognostic markers and criteria to initiate therapy in Waldenstrom's macroglobulinemia: consensus panel recommendations from the Second International Workshop of Waldenstroms Macroglobulinemia. Semin Oncol 2003;30(2):116-20.
3. Treon SP, Merlini G, et al. Waldenstrom's Macroglobulinemia/Lymphoplasmacytic Lymphoma. http://www.stevenptreon.com/WM.htm . Last accessed October 28, 2013.
4. Vijay A, Gertz MA.Waldenström macroglobulinemia. Blood 2007;109(12):5096-103.