In the most malignant form of plasma cell dyscrasias, primary plasma cell leukemia, the plasma cell population contains >1900 distinct DNA alterations in >600 genes.In general, the plasma cell dyscrasias are defined by 1) the presence of these genetically unstable clonal plasma cells, lymphoplasmacytoid cells, or B cells infiltrating the bone marrow or forming distinct masses in bone, and/or other tissues as defined by biopsy of involved tissues and 2) the presence of these cells myeloma proteins (i.e. intact monoclonal antibody, free light chain, free heavy chain, shortened version of these proteins, or any combination of these proteins) in blood and/or urine as defined by various types of gel electrophoresis. Obviously, the latter criterion does not apply to the rare cases of true non-secretory myeloma. Myeloma protein toxicity
Myeloma proteins form as a result of gene mutations rather than physiological gene remodeling responses to an instigating foreign antigen: typically these proteins are non-functional. However, they  sometimes cause serious tissue damage with the kidney being a particularly vulnerable target. The toxic effects of monoclonal proteins may occur at early stages in the plasma cell dyscrasia spectrum and require treatment independently of the mass or tissue-destructive effects of the myeloma protein-producing cells.
In general, patients with plasma cell myeloma with concomitant chronic Lymphocytic Leukemia/monoclonal B-cell Lymphocytosis have been treated with the same regimens used for multiple myeloma patients unless significant complications related to the lymphocytic component of their disease (e.g. autoimmune hemolytic anemia) require treatments used in chronic lymphocytic leukemia. Some patients who lack appreciable symptoms have been followed with no specific treatment of their disease. Waldenström macroglobulinemia
According to the International Workshop on Waldenströms Macroglobulinemia, the disease is diagnosed in patients that have a serum IgM monoclonal protein and a bone marrow that contains ≥10% of its nucleated cells as lymphoplasmacytic cells. There is no requirement for symptomatic disease, a particular level of IgM protein, or presence of extramedullary (i.e. non-bone) lymphoplasmacytic cell infiltrates. The overall survival for this malignancy at 5 and 10 years among >5,000 patients is 62% and 39%, respectively, with newer treatment regimens anticipated to improve these survival rates in the future. Multiple myeloma
Multiple myeloma is diagnosed in patients that (except for non-secretory multiple myeloma patients) have a clonal IgG, IgA, IgD, or IgE myeloma protein in their serum and/or a clonal κ or λ light chain in their serum or urine plus either one of two sets of criteria.