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Bone Marrow Aspiration and Biopsy

Bone marrow aspiration (sometimes called bone marrow aspirate) and biopsy are tests performed to examine a patient’s bone marrow.

Graphic showing cross section of a bone with exposed bone marrow (labeled as the soft inner tissue of bones where blood cells are formed). On the right, a graphic of blood stems cells branches into white blood cells, red blood cells, and platelets.

Bone marrow is a soft, spongy material in the center of most of the body’s bones that works like a blood cell factory.

Bone marrow is a soft, spongy material that is in the center of most of the body’s bones. Bone marrow works like a blood cell factory. It makes blood-forming (hematopoietic) cells, the parents of all other blood cells. They mature into cells that eventually become:

  • Red blood cells (which carry oxygen)
  • Platelets (which help the blood clot)
  • White blood cells (which fight infection)

In childhood cancer, bone marrow aspirations and biopsies may be performed to:

  • See if the bone marrow is producing enough of certain blood cells
  • Diagnose blood cancers, such as childhood leukemia and lymphoma
  • Determine if cancers have spread from other parts of the body to the bone marrow
  • See if bone marrow is responding to treatments
  • Diagnose infections of the bone marrow

How Bone Marrow Tests Are Performed

Many patients will have an aspiration and biopsy at the same time. Sometimes patients only have a bone marrow aspiration.

Bone marrow has a liquid portion and a more solid portion. The liquid portion is removed during an aspiration. The solid portion is removed during a biopsy.

Preparing for bone marrow tests

Most children receive sedation medication and sleep during the procedure. When patients receive sedation, they must follow rules for eating and drinking before having the test. If patients do not follow the rules regarding food and drink, the procedure will have to be rescheduled.

If the child does not have a central line or port, he or she will receive sedation medicine through an IV.

Bone marrow aspiration

A doctor, nurse practitioner, or physician assistant typically performs the procedure. A small sample of bone marrow is removed using a thin, hollow needle attached to a syringe.

  • Samples are usually taken from the patient’s hipbone.
  • Numbing medication, either a cream or a liquid that is injected, may be applied at the procedure site.
  • Patients usually lie on their side.
  • The person performing the procedure will feel the patient’s lower back to find the right spot for the test.
  • The area will be cleaned with a germ-killing liquid. The liquid will feel cold. Then, the health care provider might place plastic towels over the back, leaving only a small area of skin showing.
  • The provider will insert the needle, which will be attached at a syringe. The patient will feel some hard pushing if he or she is awake.
  • The provider will pull some liquid marrow (which looks like blood) into a syringe. If awake, the patient may feel some quick, sharp pain for an instant.
  • It is not unusual for the provider to attach more than one syringe if more samples are needed. The patient’s body will quickly replace the small amount of the fluid that has been taken out.
  • The health care provider will take out the needle, clean the spot, and put on a bandage.
Patient laying on side with needle being inserted into hip bone for bone marrow aspiration

Patients usually lie on their side, and the sample is typically taken from the patient's hipbone.

Graphic showing a biopsy needle inserted through the skin and into the bone to receive bone marrow sample

A small sample of bone marrow is removed using a thin, hollow needle attached to a syringe.

Bone marrow biopsy

  • If both an aspiration and biopsy are done, a separate needle will be used for each procedure.
  • For a biopsy, the provider will insert a larger needle into the same area to remove a small piece of bone tissue with enclosed marrow.
  • The biopsy is typically performed right before or after the aspiration.

The total time for both procedures is usually about 30 minutes.


Reviewed: June 2018

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