Multiple myeloma and bone

International audience

<p>Multiple myeloma (also called Kahler's disease [MM]) is a hematological malignancy of B lymphocytes characterized by the expansion of a malignant plasma cell clone in the bone marrow. Five thousand cases of myeloma are diagnosed each year in France, 54% in men. In almost all cases, the malignant plasma cells secrete a monoclonal immunoglobulin or an immunoglobulin fragment (free light chain) which can be detected in the blood and/or urine. This is currently the most common way of diagnosis after having prescribed an electrophoresis or an immunofixation of serum proteins. Indeed, MM is often preceded by a monoclonal gammopathy of undetermined significance (MGUS), which requires a long term biological monitoring. MGUS are 100 times more common than MM (and are observed in 3–4% of the population after 50 years) and their evolution towards an overt myeloma is approximately 1% per year. MM is a hematological malignancy whose incidence is correlated to the aging of the population (the mean age at diagnosis is about 70 years).</p>