What happens in myeloma?
As with other cancers, what seems to happen is that the cancer starts with one abnormal cell. In the case of myeloma, one plasma cell at first becomes cancerous. This abnormal cell then multiplies to produce many identical abnormal plasma cells (a ‘clone’ of cells). The cancerous plasma cells mainly collect in the bone marrow and continue to multiply without any control. In the vast majority of cases of myeloma, the abnormal plasma cells make large quantities of one antibody. This single type of antibody is called a paraprotein (or sometimes called a monoclonal antibody, as it is an antibody which comes from a single clone of plasma cells). There are several different types of antibody. (Antibodies are sometimes called immunoglobulins or Ig for short.) These are called IgM, IgG, IgA, IgD and IgE. Myelomas are sub-classified by the type of antibody that they make. For example, IgG myeloma is the most common type.
