Multiple myeloma is a cancer of plasma cells in the bone marrow that make large amounts of one abnormal antibody, called the M protein. It mostly affects older adults and damages bones, kidneys and blood counts, summed up as CRAB: high calcium, renal failure, anemia and bone lesions.
Key symptoms
- Bone pain, often in the back or ribs, worse with movement
- Fatigue and weakness from anemia
- Thirst, constipation and confusion from high calcium
- Frequent infections
- Weight loss; fractures after minor trauma
What you find on exam
- Tenderness over the spine, ribs or pelvis
- Pallor
- Dehydration and confusion with high calcium
- Neurologic exam of the legs for cord compression
Tests
- Blood count, calcium, creatinine, albumin and total protein (a high protein gap is a clue)
- Serum protein electrophoresis with immunofixation and serum free light chains
- Low-dose whole-body CT, PET-CT or MRI to find bone lesions
- Bone marrow biopsy: 10 percent or more clonal plasma cells
Treatment basics
- Induction therapy planned with oncology, such as bortezomib, lenalidomide and dexamethasone, often with daratumumab
- Autologous stem cell transplant in eligible patients, then maintenance
- Zoledronic acid or denosumab to protect bones
- High calcium: IV fluids and a bisphosphonate; avoid NSAIDs and IV contrast when possible
- Prevent infection with vaccines, and antiviral prophylaxis on bortezomib
Red flags
- Back pain with leg weakness, numbness or bladder problems: spinal cord compression
- Confusion, vomiting or very high calcium
- Rising creatinine, or headache and blurred vision from thick blood (hyperviscosity)
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.