Multiple myeloma is a cancer of your plasma cells, a type of white blood cell present in your bone marrow the soft, blood-producing tissue that fills in the center of most of your bones. The cause of this disease isn't known.
Plasma cells usually make up less than 5 percent of the cells in your bone marrow. But if you have multiple myeloma, a group of abnormal plasma cells (myeloma cells) multiplies to make up more than 10 percent of the cells in your bone marrow. The result can be erosion of your bones. The disease also interferes with the function of your bone marrow and immune system, which can lead to anemia and infection. More infections tend to occur later in the disease. Multiple myeloma may also cause problems with your kidneys.
The disease is called multiple myeloma because abnormal myeloma cells can occur in multiple bone marrow sites in your body.
If you have the disease but you're not experiencing symptoms, you may just need your doctor to monitor your condition. A variety of treatments are available if you're experiencing symptoms.
Signs and symptoms
Although multiple myeloma may not cause symptoms early in the disease, it's likely that you'll experience symptoms as the disease progresses.
Signs and symptoms of the disease can vary from person to person. One sign is the presence of abnormal proteins which can be produced by myeloma cells in your blood or urine. These proteins which are antibodies or parts of antibodies are called monoclonal or M proteins.
Normally, your body produces a number of types of plasma cells. These cells provide a variety of antibodies that function as part of the body's immune system. They're considered polyclonal because they represent many types of plasma cells. However, if one of these cells escapes normal regulation and grows independently of the others, this is called a monoclonal growth of plasma cells. Such monoclonal plasma cells produce a monoclonal protein.
Often discovered during a routine exam, these proteins may indicate multiple myeloma, but also can indicate other conditions.
Another potential sign of multiple myeloma is a high level of calcium in your blood This can occur when calcium from affected bones dissolves into your blood. As a result, you may experience signs and symptoms such as:
Anemia can occur as myeloma cells replace oxygen-carrying red blood cells in your bone marrow, which may lead to another common symptom fatigue.
Other signs and symptoms of multiple myeloma may include:
Although the cause isn't known, multiple myeloma begins with one abnormal plasma cell in your bone marrow. This abnormal cell then starts to multiply. Because they don't mature and then die as normal cells do, they accumulate, eventually overwhelming the production of healthy cells. Healthy bone marrow consists of a small percentage of plasma cells. But in people with multiple myeloma, that percentage of plasma cells often increases to more than 10 percent.
The growth of myeloma cells (bluish-stained cells) inhibits the growth of normal bone marrow cells....
Because myeloma cells may circulate in low numbers in your blood, they can populate other bone marrow sites in your body, even far from where they began. Uncontrolled plasma cell growth can damage bones and surrounding tissue. It can also interfere with your immune system's ability to fight infections by inhibiting your body's production of normal antibodies.
Experts aren't sure why this process begins. But, researchers are studying the DNA of plasma cells to try to understand what changes occur that cause these cells to become cancer cells. Though they haven't yet discovered the cause of these changes, they have found some common abnormalities in myeloma cells. For example, many myeloma cells are missing all or part of one chromosome chromosome 13. Cells with a missing or defective chromosome 13 tend to be more aggressive and harder to treat than cells with a normal chromosome 13.
Multiple myeloma often develops from a harmless condition called monoclonal gammopathy of undetermined significance (MGUS). This condition, like multiple myeloma, is marked by the presence of M proteins produced by abnormal plasma cells in your blood. However, in MGUS, the amount of the abnormal proteins isn't high enough to cause harm and no damage to the bones occurs. The cause of MGUS is unknown.
Multiple myeloma isn't contagious. Most people who develop multiple myeloma have no clearly identifiable risk factors for the disease.
Some factors that may increase your risk of multiple myeloma include:
When to seek medical advice
If you're persistently more tired than you used to be, you've lost weight, and you experience bone pain, repeated infections, loss of appetite, excessive thirst and urination, persistent nausea, increased constipation, or weakness or numbness in your legs, these may indicate multiple myeloma or other serious diseases. See your doctor to determine the underlying cause.
Screening and diagnosis
Your doctor may first detect signs of multiple myeloma before you ever have symptoms through blood and urine tests conducted during a routine physical exam.
Generally, doctors conduct a blood test called serum protein electrophoresis as part of an exam. This test separates your blood proteins and can detect the presence of abnormal, M proteins in the blood. Parts of M proteins may also be detected in a test of your urine referred to as Bence Jones proteins.
If your doctor discovers M proteins, you'll likely need additional blood tests to measure blood cell counts and levels of calcium, uric acid and creatinine. Your doctor may also conduct other blood tests to check for beta-2-microglobulin another protein produced by myeloma cells or to measure the percentage of plasma cells in your blood.
You may also need other tests. X-rays of your skeleton can show whether your bones have any thinned-out areas, common in multiple myeloma. If a closer view of your bones is necessary, your doctor may use magnetic resonance imaging (MRI) or computerized tomography (CT) scanning. Your doctor may also conduct a bone marrow examination by using a needle to remove a small sample of bone marrow tissue. The sample is then examined under a microscope to check for myeloma cells.
These tests can help confirm whether you have multiple myeloma or another condition. If tests indicate you have multiple myeloma, the results from these tests allow your doctor to classify the stage of myeloma. Stages range from Stage I (low amount of myeloma) to Stage III (high amount of myeloma) and A (normal kidney function) or B (abnormal kidney function) as multiple myeloma often causes damage to your kidneys.
Myeloma cells inhibit the production of antibodies needed for normal immunity. Having multiple myeloma may make you more likely to develop infections, such as pneumonia, sinusitis, bladder or kidney infection, skin infections and shingles. Other complications of the disease include erosion of bone mass and fractures, due to the damage multiple myeloma can cause to your bones. Uncommonly, multiple myeloma may cause compression of your spinal cord. This medical emergency usually begins with stool or urinary incontinence and weakness in your legs.
Problems with kidney function, including kidney failure, are another potential complication of multiple myeloma. Higher calcium levels in the blood due to eroding bones can interfere with your kidneys' ability to filter your blood's waste. The proteins produced by the myeloma cells can cause similar problems, especially if you become dehydrated.
Multiple myeloma can also cause anemia and other blood problems as cancerous cells crowd out normal blood cells.
Generally, if you have multiple myeloma and aren't experiencing symptoms, you don't need treatment. However, your doctors will likely monitor your condition at three- to six-month variable intervals, checking for signs such as increasing levels of M protein in your blood or urine that the disease is progressing. If it is, you may need treatment to help prevent symptoms.
If you're experiencing symptoms, treatment can help relieve pain, control complications of the disease, stabilize your condition and slow the progress of the disease.
Though there's no cure for multiple myeloma, if you have good treatment results you can usually return to near-normal activity. The appropriate treatment depends on your needs, medical status and general health. Standard treatment options include:
Other available treatments are being studied to determine their place in treatment of multiple myeloma. Your doctor can discuss with you whether these treatments are appropriate for you. Some of these include:
Because multiple myeloma can cause a number of complications, you may also need treatment for those specific conditions. One example is pain medication or wearing a back brace to help relieve the back pain you might experience with multiple myeloma. People with severe kidney damage may need dialysis. Also, antibiotics may be necessary to help treat infections or to help reduce your risk of them.
The following tips may help you keep multiple myeloma under control:
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