[Significance of monoclonal macroglobulinemia]

A monoclonal IgM protein in the plasma results from an expansion of a B lymphoid clone which encompasses a spectrum of different diseases: transient clones, monoclonal gammopathy of undetermined significance, Waldenström's macroglobulinemia and other B lymphoid malignancies, or primary amyloidosis. The main symptoms are related to the M component concentration and specific properties, the tumor development or both. Prognosis best correlates with the underlying histologic disorder.