Multiple myeloma (aka Plasma cell myeloma), is an abnormal proliferation of plasma cells, a type of white blood cell present in the bone marrow. Normal plasma cells are responsible for making antibodies that helps the body fight infections. In multiple myeloma, these plasma cells are unregulated in their production and therefore they make useless antibodies. These antibodies are IgG or IgA which do not fight infections but clog up the kidney.
Sings and symptoms of Multiple Myeloma:
- Bone pain: This is the most common presentation of multiple myeloma. Most commonly back pain and rib pain since the osteoclast activating factors area causing bone lysis. The bone pain is due to pathologic fracture which a fracture of a bone under what we would consider normal use.
- Anemia: It results from the replacement of normal bone marrow by infiltrating tumor cells and inhibition of normal red blood cell production
- Renal failure: The most common cause of renal failure in multiple myeloma is due to tubulopathic effects of the light chains (Bence Jones proteins). Increased bone resorption leads to hypercalcemia and causes nephrocalcinosis thereby contributing to the renal failure.
- Infection: This is due to immune deficiency. Although the total immunoglobulin level is typically elevated in multiple myeloma, but these immunoglobulins are useless and are not able to fight the infections.
- Constipation: is due to electrolyte disturbances such as hypercalcemia.
- Neurological symptoms: Common problems are weakness, confusion and fatigue due to hypercalcemia. Headache, visual changes and retinopathy may be the result of hyperviscosity of the blood depending on the properties of the paraprotein.
- Renal failure and infection are the most common causes of death in multiple myeloma.
Multiple Myeloma Mnemonic:
Diagnostic Test for Multiple Myeloma:
- X-ray is usually the first test that is done of the affected bone that will show lytic also known as “punched out” bone lesions.
- Magnetic resonance imaging (MRI) is more sensitive than simple X-ray in the detection of lytic lesions, and may supersede skeletal survey, especially when vertebral disease is suspected.
- CT scan is occasionally performed to measure the size of soft tissue plasmacytomas.
- Serum protein electrophoresis (SPEP) which will show an IgG or IgA spike of a single type or clone. This is called Monoclonal or “M” spike.
- Peripheral blood smear may show the rouleaux formation of red blood cells, though this is not specific.’
Other laboratory abnormalities include:
- Bence-Jones proteins on urine immunoelectrophoresis
- Beta2 microglobulin levels correspond to severity of disease
- Elevated BUN and creatinine (due to Renal failure)
- Greater than 10% plasma cells on bone marrow biopsy
Treatment of Multiple Myeloma:
Initial treatment of multiple myeloma depends on the patient’s age and comorbidities.
- Autologous hematopoietic stem-cell transplantation has become the preferred treatment for patients under the age of 65 in recent years along with high-dose chemotherapy.
- Thalidomide–dexamethasone, bortezomib based regimens, and lenalidomide–dexamethasone, The most common induction regimens used today.
Patients over age 65 and patients with significant concurrent illness often cannot tolerate stem cell transplantation. For these patients, the standard of care has been:
- Chemotherapy with Melphalan and Prednisone.