Words to know: Multiple myeloma
- Plasma cell
- A white blood cell in the bone marrow that makes antibodies to fight infection. Myeloma is a cancer of these cells.
- Bone marrow
- The soft tissue inside bones where blood cells are made.
- M-protein
- The abnormal antibody protein made by myeloma cells. Also called monoclonal protein or M-spike. It is used to track the disease.
- Light chains
- Small pieces of antibody protein. Myeloma cells may make too much of one type, which is measured by the free light chain test.
- MGUS
- Monoclonal gammopathy of undetermined significance. A common early condition with a small amount of M-protein and no cancer damage.
- Smoldering myeloma
- A stage between MGUS and active myeloma, with more abnormal cells or protein but no organ damage.
- CRAB
- Signs of damage from myeloma: high calcium, kidney (renal) problems, anemia, and bone damage.
- Anemia
- Too few red blood cells, which can cause tiredness and shortness of breath.
- Lytic lesion
- A hole or weak spot in a bone caused by myeloma.
- FISH
- A lab test on myeloma cells that looks for chromosome changes that affect risk.
- Induction
- The first phase of treatment, meant to bring the myeloma under control.
- Quadruplet
- A treatment combination of 4 drugs given together.
- Autologous stem cell transplant
- Treatment that uses high-dose chemotherapy followed by the return of your own saved stem cells.
- Maintenance
- Lower-intensity treatment taken for a long time to keep myeloma under control.
- Relapse
- When myeloma comes back or starts growing again after treatment.
- Refractory
- Myeloma that does not respond, or stops responding, to a treatment.
- MRD (minimal residual disease)
- Tiny amounts of myeloma left after treatment, found only by very sensitive tests. MRD-negative means none were found.
- CAR-T cell therapy
- A treatment where your own immune T cells are changed in a lab to attack myeloma, then given back to you.
- Bispecific antibody
- A drug that links an immune T cell to a myeloma cell so the immune system can attack it.
- BCMA
- A protein on the surface of myeloma cells that many CAR-T and bispecific treatments target.
- Cytokine release syndrome (CRS)
- A strong immune reaction after CAR-T or bispecifics that can cause fever and low blood pressure.
- Neuropathy
- Nerve damage that causes numbness, tingling, or pain, usually in the hands and feet.
- Proteasome inhibitor
- A drug type, such as bortezomib or carfilzomib, that blocks the machinery myeloma cells use to clear out waste proteins.
- Immunomodulatory drug (IMiD)
- A drug type, such as lenalidomide or pomalidomide, that attacks myeloma and boosts the immune system.
- Osteonecrosis of the jaw
- A rare problem where part of the jaw bone does not heal, linked to bone-strengthening drugs.
Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.