Multiple Myeloma and Plasma Cell Disorders
Multiple myeloma is a cancer of plasma cells within the bone marrow. Normal plasma cells are a type of white blood cell that produces antibodies (specialised proteins that defend against infection).When plasma cells become cancerous, they can be present in large quantities in the bone marrow of the vertebrae, pelvis, sternum and ribs. The abnormal plasma cells cause problems by damaging the bone itself, weakening it and causing bone fractures and sometimes causing high calcium levels in the bloodstream. Myeloma plasma cells can crowd out the healthy bone marrow and interne with red cells, white cells and platelets. Instead of producing healthy antibodies, the myeloma plasma cells produce an abnormal protein, called a paraprotein or M protein. The abnormal paraprotein causes problems by reducing healthy antibody production, increasing the likelihood of infections. The paraprotein can be toxic to kidneys, and rarely can deposit in tissues as insoluble protein – a complication called Amyloidosis.
Other plasma cell disorders include: monoclonal gammopathy of unknown significance (MGUS) – where there is a paraprotein and only a small number of abnormal plasma cells in the bone marrow, and solitary plasmacytoma (a single lump of abnormal plasma cells).
Monoclonal gammopathy of unknown significance
Monoclonal gammopathy of unknown significance (MGUS) is a pre-cancerous condition of abnormal plasma cell production. “Monoclonal” means that the protein is being made from a single abnormal clone of plasma cells, “gammopathy” means a pathological protein, and “ unknown significance” refers to the fact that there is a small risk that this condition can develop into myeloma. Patients with a diagnosis of MGUS need to be monitored with regular blood tests and urine tests.
Solitary plasmacytoma
Solitary plasmacytoma is a single ‘lump’ of abnormal plasma cells affecting only one bone in the body. Solitary plasmacytoma is usually treated with radiation therapy. There is a risk that solitary plasmacytoma can develop into myeloma, so patients with this disorder are monitored with regular blood and urine tests, and sometimes scans
