multiple myeloma
Meaning of multiple myeloma: Harm arrives from two directions at once: cells crowding the marrow, and the abnormal protein those cells pour into the circulation.
Definition of multiple myeloma
Multiple myeloma is a cancer of plasma cells, the mature white blood cells that normally manufacture antibodies. Abnormal plasma cells multiply unchecked inside the bone marrow, usually at many sites in the skeleton at once, and release a single useless antibody protein into the blood. That combination damages bone, blood counts and kidneys together.
What does it do to the body?
Four consequences define the disease, and they arise from the two problems named above. Crowded marrow cannot make normal blood, and the abnormal protein does damage of its own wherever it travels.
- Bone. Myeloma cells activate the cells that dissolve bone and suppress those that rebuild it, leaving punched-out holes, pain, and fractures from forces that would not normally break anything.
- Calcium. Bone breakdown releases calcium into the blood, which causes thirst, constipation, drowsiness and confusion.
- Kidneys. Fragments of the abnormal antibody, called light chains, are filtered into the urine and clog and injure the tubules.
- Blood. Anemia causes fatigue and breathlessness, low platelets cause bruising, and a shortage of normal antibodies leaves infections harder to fight even though one antibody is present in flood.
How does it differ from related plasma cell conditions?
| Condition | What is present |
|---|---|
| Monoclonal gammopathy of undetermined significance | Abnormal protein in the blood, few plasma cells, no organ damage |
| Smoldering myeloma | More plasma cells or more protein, still no organ damage |
| Solitary plasmacytoma | One isolated mass of plasma cells rather than diffuse marrow disease |
| Multiple myeloma | Marrow involvement together with damage to bone, kidney, blood or calcium |
These form a continuum rather than separate diseases, and a person may move along it over years. That is why smoldering myeloma is followed rather than treated at once: what separates it from active disease is the absence of damage, not the absence of abnormal cells.
Why is it treated as a long-running condition?
Because the abnormal protein gives an unusually direct measure of how much disease is present, its level in blood and urine can be tracked over time, and the pattern that emerges is one of control, relapse and renewed control rather than a single course ending in cure. Treatment is therefore planned in phases and adjusted according to how the marker moves. The name records the pattern seen on imaging: not one tumor but many separate sites of marrow disease scattered through the skeleton.
Also known as
Used in a sentence
Bone marrow biopsy confirmed a diagnosis of multiple myeloma.
Good to know
Multiple myeloma is distinguished from a solitary plasmacytoma, in which abnormal plasma cells form a single isolated mass rather than involving marrow at multiple sites.
Word origin
Where “multiple myeloma” comes from
Formed from myelo-, from Greek myelos, meaning marrow, combined with -oma, meaning tumor, reflecting the disease's origin within bone marrow.