Cancer of Plasma Cells (Cancer of Myeloma Cells) (Multiple Myeloma)
Multiple myeloma is a bone marrow cancer involving a type of white blood cell called a plasma (or myeloma) cell. The tumor cells can form a single collection (a plasmacytoma) or many tumors (multiple myeloma). Plasma cells are part of the immune system and make antibodies. Because patients have an excess of identical plasma cells, they have too much of one type of antibody. This form of antibody is called para-protein and it is present in blood and/or urine in about 99% of cases. Normal antibody levels are almost always reduced and this, combined with a slight reduction in the number of neutrophils, leads to a susceptibility to infection which may be life threatening. As myeloma cells increase in number, they damage and weaken the bones, causing pain and often fractures. When bones are damaged, calcium is released into the blood leading to hypercalcemia (excess calcium in the blood) and that causes loss of appetite, nausea, thirst, fatigue, muscle weakness, restlessness, and confusion. Myeloma cells prevent the bone marrow from forming normal plasma cells and other white blood cells important to the immune system so patients may not be able to fight infections. The cancer cells can also prevent the growth of new red blood cells, causing anemia. Excess antibody proteins and calcium may prevent the kidneys from filtering and cleaning the blood properly.