Inside the hollow area of the bones is a spongy core called bone marrow. It is here, that stem cells are produced. Stem cells are immature cells that can develop into components of blood including white blood cells, which fight infection.
Plasma cells are mature white blood cells that enter the bloodstream. From the bloodstream they are carried to the lymphatic system where they make antibodies. Antibodies help protect the body from germs and other harmful substances.
Myeloma is cancer of plasma cells in the bone marrow. As the abnormal cells divide, more and more healthy plasma cells are replaced by the abnormal myeloma cells. As the percentage of myeloma cells outnumber the healthy plasma cells, tumors form inside the bone marrow and solid part of the bone. Because multiple bones are usually affected, the cancer is called multiple myeloma.
Even though the bones are affected, this is not considered bone cancer, but a plasma cell cancer. Symptoms of multiple myeloma can include bone pain, fractures, anemia, and susceptibility to infection. Kidney damage may develop as the cancer progresses.
When myeloma cells enter the bloodstream and then travel to the lymphatic system, they do not make the normal plasma antibodies. Instead they produce an antibody called monoclonal protein or M protein. M protein and its byproducts can be detected in blood and urine tests. Bone marrow can be obtained by bone marrow biopsy or bone marrow aspiration. However, microscopic analysis of bone marrow showing myeloma cells is needed to diagnose multiple myeloma.
Treatment can include chemotherapy, radiation, and stem cell transplants. Multiple myeloma is not a curable disease. Instead, treatment may be aimed at controlling symptoms and providing comfort care.