myeloma
Meaning of myeloma: One plasma cell clone takes over the marrow and floods the blood with a single useless antibody, damaging bone and kidneys as it grows.
Definition of myeloma
Myeloma is a cancer of plasma cells, the mature white blood cells that normally manufacture antibodies. The abnormal cells build up inside the bone marrow, usually at many sites at once, which is why the disease is generally called multiple myeloma. Most produce a single identical antibody protein that offers no protection and can itself damage the kidneys.
How myeloma is built
- myel/o Combining form · Greek bone marrow, spinal cord
- -oma Suffix · Greek tumour, mass, swelling
A medical term is read from its ending backwards: the suffix first, then the prefix, then the root. See all 223 word parts.
What damage does it do?
| Feature | How it arises |
|---|---|
| Raised blood calcium | Bone is dissolved faster than it is rebuilt, releasing calcium into the blood |
| Kidney impairment | Fragments of the abnormal antibody are filtered in large amounts and block the kidney tubules |
| Anemia and low blood counts | Myeloma cells crowd out normal blood cell production in the marrow |
| Bone pain and fractures | Punched out areas of bone loss weaken the spine, ribs, skull and long bones |
These four features are the backbone of the disease and often the reason someone seeks help in the first place, usually for back pain, tiredness or a fracture after minor force. Infections are frequent as well, because the flood of one useless antibody comes at the expense of the varied ones that actually work. The protein involved is usually described as a monoclonal protein or paraprotein, and it is the free light chain portion rather than the whole molecule that does most of the harm to the kidney.
Does it always begin as cancer?
No, and that is one of the more useful things to understand about it. A harmless precursor state, monoclonal gammopathy of undetermined significance, is common with age and involves the same abnormal protein without any organ damage. A proportion of cases advance to smoldering myeloma, in which more abnormal plasma cells are present but the person is still well, and a share of those in turn become active disease. A solitary plasmacytoma sits apart from all of this: a single mass of the same cells in one bone or soft tissue, with a marrow that is otherwise normal.
How is it identified?
Blood and urine are tested for the abnormal protein and for the free light chains, alongside counts, calcium and kidney measures. A sample of bone marrow is drawn to see what proportion of the cells are plasma cells and to look at their chromosomes, since certain changes shape how the disease behaves. Imaging of the whole skeleton finds areas of bone loss that plain films miss. The pattern across all three, rather than any single result, decides whether the disease is active.
Used in a sentence
Bone marrow biopsy confirmed a diagnosis of myeloma after the patient presented with bone pain and anemia.
Good to know
Myeloma is distinct from a solitary plasmacytoma, a single mass of the same abnormal plasma cells occurring at one site rather than spread through the bone marrow.
Word origin
Where “myeloma” comes from
Formed from myelo-, Greek for marrow, and -oma, meaning tumor.