Bone Marrow Tests

What are bone marrow tests?

Bone marrow is a soft, spongy tissue found in the center of your bones. Bone marrow makes different types of blood cells, including:

• Red blood cells (also called erythrocytes), which carry oxygen from your lungs to every cell in your body.
• White blood cells (also called leukocytes), which help you fight infections.
• Platelets, which help with blood clotting.

Bone marrow tests remove a sample of your bone marrow and bone. The sample is usually taken from the back of your hip. It is examined under a microscope and tested to look for signs of disease.

Bone marrow tests help find out whether your bone marrow is working well to make normal amounts of healthy blood cells. Bone marrow tests can help diagnose and monitor bone marrow disorders, blood disorders, and certain types of cancer.

There are two types of procedures used to collect bone marrow samples for testing:

• Bone marrow aspiration removes a small amount of fluid and cells from your bone marrow.
• Bone marrow biopsy removes a small piece of bone and bone marrow.

Bone marrow aspiration and bone marrow biopsy are usually done at the same time.

Other names: bone marrow examination

What are they used for?

Bone marrow tests are used to help find the cause of too many or too few blood cells, or blood cells that don't look normal. The results can help:

• Diagnose blood and bone marrow disorders, such as:
  • Anemia (when the cause is unknown)
  • Hemochromatosis
  • Myelodysplastic syndromes
  • Polycythemia vera
  • Platelet disorders
  • Certain cancers involving blood and bone marrow, including leukemia, multiple myeloma, and lymphoma
• Plan and monitor treatment for conditions that involve your blood or bone marrow
• Find out if certain types of cancer, such as breast, lung, or prostate cancer, have spread to your bone marrow
• Find the cause of an unexplained fever, which could be from a bone marrow infection

Why do I need bone marrow tests?

You may need a bone marrow aspiration and a bone marrow biopsy if you:

• Had abnormal results on other blood tests, such as a complete blood count (CBC) or a blood smear
• Have signs and symptoms, and a medical history that could mean you have a bone marrow disease
• Have certain types of cancers that involve your blood and bone marrow, and your health care provider needs to know how much cancer is in your body (This is called "cancer staging.")
• Have a type of cancer in another part of your body that commonly spreads to bone marrow
• Are being treated for a condition that affects your blood or bone marrow, and your provider needs to find out how well your treatment is working

What happens during a bone marrow test?

Bone marrow aspiration and bone marrow biopsy procedures are usually done at the same time. A provider will collect the marrow samples for testing. Usually, the samples can be collected in about ten minutes. The procedure may be done in a hospital, provider's office, or clinic.

Before the procedure, you may be asked to put on a hospital gown. Your blood pressure, heart rate, and temperature will be checked.

You may choose to have a mild sedative, which is medicine to help you relax. You may also have the choice to use stronger medicine that will make you sleep. Your provider can help you decide which option is best for you.

During the procedure:

• You'll lie down on your side or your stomach, depending on which bone will be used for the samples. Most bone marrow samples are taken from a bone in the back of your hip, called the iliac crest. But other bones may be used.
• The skin over the bone will be cleaned with an antiseptic.
• You will get an injection (shot) of medicine to numb your skin and the bone underneath. It may sting.
• When the area is numb, your provider will make a very small incision (cut) in your skin and insert a hollow needle. You will need to lie very still during the procedure:
  • For the bone marrow aspiration, your provider pushes a thin needle into the bone and removes a sample of bone marrow fluid with a syringe attached to the needle. You may feel a brief some pressure or brief pain. The aspiration takes only a few minutes.
  • For the bone marrow biopsy, your provider inserts a hollow needle into the bone and twists the needle to take out a small piece of bone marrow tissue. You may feel some pressure or brief pain while the sample is being taken.
• After the test, your provider will press on your skin to stop the bleeding and then cover the area with a bandage.
• If you didn't use medicine to relax or sleep, you'll usually need to stay lying down for about 15 minutes to make sure that the bleeding has stopped. If you used medicine to relax or sleep, you'll need to stay longer before you can go home.
• Your provider will tell you how to care for yourself after your test. You may need to avoid hard physical activity and keep the bandage dry for at least a day. You may feel sore for a week or more. Your provider can tell you which pain relievers are safe to use.

Will I need to do anything to prepare for the test?

You'll receive complete instructions for how to prepare.

• You may need to stop taking certain medicines before this test, so tell your provider about everything you take. But don't stop taking any medicines unless your provider tells you to.
• Tell your provider if you have a bleeding disorder.
• Your provider will tell you whether you need to fast (not eat or drink) for a few hours before the procedure.
• Plan to have someone take you home after the test, because you may be drowsy if you are given medicine to help you relax or sleep during the procedure.

Be sure to ask your provider any questions you may have about the procedure.

Are there any risks to the test?

After a bone marrow aspiration and bone marrow biopsy you may feel stiff or sore where the sample was taken. This usually goes away in a few days. Your provider may recommend or prescribe a pain reliever to help.

Don't take any pain medicine your provider hasn't approved. Certain pain relievers, such as aspirin, could increase your risk of bleeding.

Serious symptoms are very rare, but may include:

• Increased pain or discomfort where the sample was taken
• Redness, swelling, bleeding, or other fluids leaking from the area where the needles were inserted
• Fever

If you have any of these symptoms, call your provider.

What do the results mean?

It may take several days or even weeks to get your bone marrow test results. Your provider may have ordered many different types of tests on your sample, so your results often include a lot of complex information. Your provider can explain what your results mean.

In certain cases, if your test results are not normal, you may need to have more tests to confirm a diagnosis or to decide which treatment would be best for you.

If you have already been diagnosed with a disease that involves your bone marrow, your test results may show:

• How well your treatment is working
• Whether your treatment is causing side effects that affect your bone marrow

Learn more about laboratory tests, reference ranges, and understanding results.