myelomatosis, multiple myeloma

myelomatosis, multiple myeloma

A malignant disorder of antibody-producing PLASMA CELLS. Plasma cells derive from a single selected B lymphocyte and produce a single monoclonal antibody (immunoglobulin). In myelomatosis, large quantities of monoclonal immunoglobulin are produced as a kind of cancer in the bone marrow that progressively replaces the blood-forming tissue and absorbs bone causing areas of OSTEOPOROSIS. There is widespread bone pain and crippling spontaneous fractures and the effects of anaemia and thickening of the blood from excessive globulins. This may affect brain function. The urine may contain considerable quantities of immunoglobulin (Bence Jones protein). Treatment is with anticancer drugs such as MELPHALAN, with total body irradiation followed by restoration of the bone marrow with autologous haematopoietic stem cells. In relapsing cases the proteasome inhibitor drug BORTEZOMIB has proved more effective than THALIDOMIDE with DEXAMETHASONE.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005