Waldenstrom's macroglobulinemia

Waldenstrom's macroglobulinemia (WM) is a clinical disease usually caused by an increase in abnormal B-lymphocytes which produce increased amounts of monoclonal immunoglobulins (typically IgM). Very high levels of IgM in the blood may cause hyperviscosity , which could explain the symptoms associated with this disease (blurred vision, headache, and dizziness). The lymphoma that is most commonly associated with WM is lymphoplasmacytic lymphoma (a low grade B-cell lymphoma).