Multiple Myeloma
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What are the key statistics about multiple myeloma?
What is multiple myeloma?
Cancer starts when cells in the body begin to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer?
Multiple myeloma is a cancer formed by malignant plasma cells. Normal plasma cells are found in the bone marrow and are an important part of the immune system.
The immune system is made up of several types of cells that work together to fight infections and other diseases. Lymphocytes (lymph cells) are the main cell type of the immune system. The major types of lymphocytes are T cells and B cells.
When B cells respond to an infection, they mature and change into plasma cells. Plasma cells make the antibodies (also called immunoglobulins) that help the body attack and kill germs. Lymphocytes are in many areas of the body, such as lymph nodes, the bone marrow, the intestines, and the bloodstream. Plasma cells, however, are mainly found in the bone marrow. Bone marrow is the soft tissue inside some hollow bones. In addition to plasma cells, normal bone marrow has cells that make the different normal blood cells.
When plasma cells become cancerous and grow out of control, they can produce a tumor called a plasmacytoma. These tumors generally develop in a bone, but they are also rarely found in other tissues. If someone has only a single plasma cell tumor, the disease is called an isolated (or solitary) plasmacytoma. If someone has more than one plasmacytoma, they have multiple myeloma.
Multiple myeloma is characterized by several features, including:
Low blood counts
In multiple myeloma, the overgrowth of plasma cells in the bone marrow can crowd out normal blood-forming cells, leading to low blood counts. This can cause anemia – a shortage of red blood cells. People with anemia become pale, weak, and fatigued. Multiple myeloma can also cause the level of platelets in the blood to become low (called thrombocytopenia). This can lead to increased bleeding and bruising. Another condition that can develop is leukopenia – a shortage of normal white blood cells. This can lead to problems fighting infections.