Test Overview

Bone marrow aspiration is a procedure that takes out a small amount of bone marrow fluid through a needle. Bone marrow biopsy uses a needle to take out a small amount of bone with the marrow inside it. These samples are then checked under a microscope. The hip bone is the most often used area for these procedures.

Aspiration and biopsy are often done to find a blood problem or an infection. They also may be used to find out if a cancer has spread to the bone marrow. The procedure can also be done to collect bone marrow for medical procedures, such as stem cell transplant or chromosomal analysis.

You may get medicine to help you relax before the procedure. The doctor will inject numbing medicine in the skin over your bone. He or she will put a needle through your skin and into your bone to reach the bone marrow. You may feel pressure or some dull pain during the procedure. After the doctor takes the sample, he or she will remove the needle. The doctor may need to take more than one sample. This can come from the same spot or from a different area on your body. When the procedure is done, the doctor or a nurse will put pressure on the area to stop any bleeding.

Why It Is Done

A bone marrow aspiration, biopsy, or both are done to:

• Look for the cause of problems with red blood cells, white blood cells, or platelets in people who have conditions such as thrombocytopenia, anemia, or an abnormal white blood cell count.
• Find blood disorders, such as leukemia, certain anemias, or problems that affect the bone marrow, such as multiple myeloma or polycythemia vera.
• Check to see if a known cancer, such as Hodgkin lymphoma or non-Hodgkin lymphoma, has spread to the bone marrow. This is part of what is called staging. It is done to find out if the cancer has spread and how much it has spread. This helps plan cancer treatment.
• Find infections or tumours that may start in or spread to the bone marrow. If you have an infection, a culture and sensitivity test of the bone marrow sample may be used to find out which antibiotics will work best to treat the infection.
• Find the best treatment for a bone marrow problem. After treatment has been started, a bone marrow aspiration and biopsy may be done to see if the leukemia cells are gone. This means the treatment is working.
• Collect a sample of bone marrow for medical procedures, such as stem cell transplant or chromosomal analysis.

How To Prepare

• Tell your doctor ALL the medicines and natural health products you take. Some may increase the risk of problems during your procedure. Your doctor will tell you if you should stop taking any of them before the procedure and how soon to do it.
• If you take aspirin or some other blood thinner, ask your doctor if you should stop taking it before your procedure. Make sure that you understand exactly what your doctor wants you to do. These medicines increase the risk of bleeding.
• Be sure you have someone to take you home. Anesthesia and pain medicine will make it unsafe for you to drive or get home on your own.

How It Is Done

This biopsy may be done in your doctor's office or in a hospital.

You may need to take off all or most of your clothes, depending on what part of the body the biopsy or aspiration is taken from. If needed, you will be given a gown to use during the biopsy.

During the test

Blood samples from a vein in your arm may be taken before the bone marrow biopsy. In rare cases, you may be given a blood product (clotting factor or platelets) into a vein (IV) in your arm to prevent bleeding after the biopsy.

Adults usually have a sample of bone marrow fluid taken from the back of the pelvic bone. In rare cases a fluid sample is removed from the breastbone (sternum) or from the front of the pelvic bone. Babies and young children may have the sample taken from the front of the lower leg bone, just below the knee. A bone marrow biopsy is only taken from the pelvic bone.

You may be given a sedative to help you relax. You will lie either on your side or face down on your belly for the biopsy. It is important that you lie still in that position during the biopsy.

The skin over the aspiration site will be cleaned with a special liquid. A medicine (local anesthetic) will be used to numb the area. Then the aspiration needle will be put through your skin and into your bone to reach the bone marrow. You need to lie very still while the sample is taken. The needle is then taken out. More than one sample may be needed. They may be taken from more than one place on your body, such as from both sides of the pelvic bone.

You will lie down for 30 to 60 minutes after the biopsy so the site can be checked for bleeding. A bandage is put on the area.

How It Feels

This procedure may be painful, but only for a few seconds. You may feel a sharp sting and burn when the anesthetic numbs your skin over the aspiration or biopsy site. You may hear a crunching sound and feel pressure and some pain when the needle enters the bone. During an aspiration, you may feel a quick, shooting pain down your leg as the sample is taken.

Risks

Serious problems from a bone marrow aspiration or biopsy aren't common. Problems may include:

• Bleeding from the biopsy site. People with bleeding problems have a higher chance for this. If you have bleeding problems, pressure will be put on the biopsy site for at least 10 minutes after the biopsy. In rare cases, you may be given a blood product (clotting factor or platelets) in a vein in your arm before the biopsy to prevent bleeding after the biopsy.
• Infection of skin or the bone (osteomyelitis) at the biopsy site.
• Injury to your heart, a lung, or a major blood vessel if the sample is taken from the breastbone (sternum). This complication is very rare. Samples are not often taken from the breastbone, so most people don't have to worry about this risk.

Results

Biopsy results are usually ready in 1 to 7 days. But it may take several weeks to get the results if genetic tests are done on the sample. The bone is put into a solution that breaks down its calcium before it is stained. The bone marrow sample is often treated with special dyes (stains) to see any changes in the blood cells more clearly.

Normal bone marrow in one site does not mean that all sites in the body are normal.