Diagnosis and follow-up of monoclonal gammopathies of undetermined significance; information for referring physicians

The prevalence of monoclonal gammopathyof undetermined significance(MGUS) is generally estimated at 3.4% in the general population over 50 years, and its incidence increases with age. MGUS represents a preneoplastic entity that can transform into multiple myeloma or other lymphoproliferative disorders. The risk of malignant transformationis estimated at 1% per year and persists over time. Predictors of malignant transformationhave been identified such as the heavy chain isotype, The level of monoclonalproteins, increasing levels of the monoclonalcomponent during the first years off follow-up, the percentage of bone marrow plasmocytosis, the dosage of serum free light chains, the presence of immunophenotypicallyabnormal plasma cells, aneuploidy, and the presence of circulating plasma cells. Prognostic scores that combine certain of these factors have been proposed and allow the identification of high-risk patients. Their use could assist in tailoring the care for each patient, based on his/her risk profile.