Multiple myeloma

Multiple myeloma (MM) is the most common malignancy arising from plasma cells, fully differentiated B lymphocytes that produce the immunoglobulin (Ig) heavy- and light-chain molecules comprising antibodies. MM is characterized by an overproduction of clonal plasma cells in the bone marrow and, in most cases, monoclonal secretion of IgG, IgA, or light-chain Ig. Symptoms of end organ damage (hypercalcemia [C], renal failure [R], anemia [A], or bone lesions [B]), herein referred to as CRAB features, were traditionally a necessary criterion for diagnosing MM; however, improvements in treatment and diagnostic techniques have led to updated diagnostic criteria, enabling intervention among patients before the onset of organ damage. Multiple myeloma is an important cause of lymphoid malignancy (LM) mortality in Western populations. In the United States in 2015, MM was estimated to account for approximately one in every five newly diagnosed LMs, and one in every three LM-related deaths.