When this happens, the disease is called multiple myeloma. This booklet deals mainly with multiple myeloma. Although plasmacytoma and multiple myeloma affect the bones, they begin in cells of the immune system. These cancers are different from bone cancer, which actually begins in cells that form the hard, outer part of the bone. Because people with multiple myeloma have an abnormally large number of identical plasma cells, they also have too much of one type of antibody.
Bone pain can make it difficult for patients to move.
When bones are damaged, calcium is released into the blood. Hypercalcemia can cause 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 that are important to the immune system. Patients may not be able to fight infection and disease. The cancer cells also may prevent the growth of new red blood cells, causing anemia .