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Bone marrow aspiration and biopsy


Bone marrow is the soft tissue in the center of many bones of your body. Its function is to make blood cells. Your child may need to have a bone marrow test done for several reasons. Your child’s medical team can test to see if the marrow is making blood cells as it should be, if leukemia or tumor cells are present, or if your child’s treatment is working correctly.

The bone marrow can be tested by aspiration or by biopsy. Aspiration means to take a sample of the liquid marrow through a needle, and biopsy means to take out a small piece of solid marrow through a needle. The hip bone is used most often for these tests.

Getting ready for the test

When your child has a bone marrow test, he will be asked to lie on his side on the bed or sit up with his legs bent and crossed at the ankles. Someone will stand beside your child and hold him tight to help him stay very still. The doctor will feel your child’s lower back to find the right spot for the test.

Next, the doctor will put on gloves and clean your child’s back with a germ-killing soap. This will feel cold. Then, the doctor might place plastic towels over your child’s back, leaving only a small area of skin showing.

Note: Most of the time before a bone marrow aspirate or biopsy, your child will be sedated (given medicine to help him relax or sleep through the procedure).

The test

About one (1) hour before the procedure, numbing cream will be placed on the spot where the bone marrow aspirate or biopsy will be taken. Liquid numbing medicine might be injected at the procedure site if your child is going to be awake during the aspirate or biopsy.

The doctor will push the aspirate needle through the numbed skin into your child’s bone marrow. Your child will feel some hard pushing if he is awake. The doctor will pull some liquid marrow into a syringe. Your child may feel some quick, sharp pain for an instant. This is the end of the bone marrow aspiration.

Sometimes, the doctor will need to do a bone marrow biopsy. If so, this will be done before or after the aspiration depending on your child’s diagnosis. The doctor will put the needle in, and your child will feel hard pushing if he is awake. The doctor will remove a small piece of solid bone marrow through the needle. Now the biopsy is over. The doctor will take the needle out of your child’s back, and the nurse will clean the spot with alcohol and put on a bandage.

After the test

Staff members will study the bone marrow under a microscope. Some studies take only a day, but others may take several days. Your child’s doctor will discuss the results of the bone marrow test with you and your child.

You should remove the bandage within 24 hours to allow air around the sore spot for healing. If your child’s back is sore, he might be given medicine to help relieve the soreness. Your child’s doctor can tell you which medicine your child should take.


If you have any questions about bone marrow aspiration and biopsy, please talk to your child’s doctor or nurse by calling 901-595-3300. If you are inside the hospital, dial 0. If you are outside the Memphis area, dial toll-free 1-866-2STJUDE (1-866-278-5833) and press 0 after you are connected.


This document is not intended to take the place of the care and attention of your personal physician or other professional medical services. Our aim is to promote active participation in your care and treatment by providing information and education. Questions about individual health concerns or specific treatment options should be discussed with your physician.

St. Jude complies with health care-related federal civil rights laws and does not discriminate on the basis of race, color, national origin, age, disability, or sex.

ATTENTION: If you speak another language, assistance services, free of charge, are available to you. Call 1-866-278-5833 (TTY: 1-901-595-1040).

ATENCIÓN: si habla español, tiene a su disposición servicios gratuitos de asistencia lingüística. Llame al 1-866-278-5833 (TTY: 1-901-595-1040).

تنبيه: إذا كنت تتحدث باللغة العربية فيمكنك الاستعانة بخدمات المساعدة اللغوية المتوفرة لك مجانا. .يرجى الاتصال بالرقم. 5833-278-866-1  (الهاتف النصي: 1040-595-901-1).