Bone Marrow Aspiration and Biopsy

Approved by the Cancer.Net Editorial Board, 12/2019

Bone marrow is the spongy, fatty tissue found inside the body's larger bones. It has liquid and solid parts. Bone marrow makes these types of blood cells:

  • Red blood cells carry oxygen to all parts of the body.

  • White blood cells help the body fight infection and disease.

  • Platelets help the blood clot and control bleeding.

Sometimes doctors need to see how well these cells develop and work. To do this, they may recommend a bone marrow aspiration and/or a bone marrow biopsy. These procedures collect a sample of bone marrow.

The results of a bone marrow aspiration and/or biopsy help doctors find out about these conditions:

  • Blood cancers, including leukemia, lymphoma, or multiple myeloma

  • A fever with an unknown cause

  • Stem cell disorders

  • Rare genetic diseases

Doctors can also use the results from these procedures to better understand a blood cancer, including its subtype and stage, determine whether a treatment is working, and monitor any side effects of chemotherapy.

What is a bone marrow aspiration and biopsy?

  • Bone marrow aspiration is a procedure that removes a sample of the liquid portion of bone marrow.

  • A bone marrow biopsy removes a small, solid piece of bone marrow.

In both procedures, the bone marrow sample usually comes from the pelvic bone. This bone is in your lower back by your hip. Doctors often do these 2 procedures at the same time. They refer to them together as a bone marrow examination. Your doctor will decide whether you need 1 or both procedures.

Who does a bone marrow aspiration and biopsy? Who analyzes the sample?

An oncologist, hematologist, another doctor, or a specially trained technologist will perform the bone marrow aspiration and biopsy.

A doctor who specializes in interpreting laboratory tests will look at the collected bone marrow cells under a microscope. This doctor is called a pathologist. The pathologist then gives the results to your doctor in a pathology report.

Getting ready for a bone marrow aspiration and biopsy

When you schedule your procedure, you will get a detailed explanation of how to prepare.

What to eat. You can usually eat or drink normally before the test. Ask your health care team ahead of time to make sure.

Topics to talk about with your health care team. You may not be able to take certain medications, such as blood thinners, before your procedure. Tell your health care team about all medications and supplements you take. Ask whether you should take them on your procedure day. You should also bring up any test concerns you have.

Insurance and cost. Before your appointment, contact your insurance provider. Find out how much of the procedure’s costs it will cover and ask how much you will have to pay.

Consent. The doctor's office or hospital will ask you to sign a consent form when you arrive for the procedure. This form states that you understand the procedure’s benefits and risks. The form also states that you agree to the procedure. If you have concerns about the procedure, talk with your doctor before you sign.

During the procedure

Where will the procedure take place? Medical specialists do bone marrow aspiration and biopsy procedures in a hospital, clinic, or their office.

How long will the procedure take? When done together, the 2 procedures usually take about 30 minutes.

What happens during the procedure?

You will receive a local anesthetic to block pain. You may also have the option to take medicine before the procedure to help you relax. Tell your health care team if you have ever had an allergic reaction to an anesthetic or if you are nervous.

In addition to local anesthetic, your doctor may suggest conscious sedation. This type of anesthesia uses pain relievers and sedatives. Under conscious sedation, you will stay awake but feel no pain. You will also have little to no memory of the procedure. Most people only receive local anesthetic for bone marrow aspirations and biopsies.

If the procedure site is your pelvic bone, you will lie on your stomach or side. You will be on an examination table or hospital bed. The medical specialist will clean the skin around the bone with an antiseptic solution. Then the specialist will inject the local anesthetic through the skin with a small needle. The medicine will go into the tissue next to the bone. You will feel a slight stinging sensation. Then the area will go numb.

If you need both procedures, bone marrow aspiration usually comes first. The doctor inserts a hollow needle into the numbed area and pushes gently into the bone. Then, he or she removes the center portion of the hollow needle and attaches a syringe to the needle. The syringe withdraws the liquid portion of the bone marrow. You may feel a deep, dull, aching pain for a few seconds, similar to a toothache. It may help to squeeze a pillow or someone’s hand. After the needle comes out, the pain goes away.

For the bone marrow biopsy, the medical specialist inserts a larger needle into the same area. They will guide the needle into the bone and rotate it to remove a sample of tissue. You may feel pain and pressure as the needle moves into the bone. The medical specialist will then remove the entire needle. Next, they will place a bandage over the site to prevent bleeding.

After the procedure

If your procedure takes place at a clinic, you can go home shortly after it is over. But if you received sedation, you will first need to lie down for about 20 minutes. That way the medicine’s effects can wear off. You will also need a ride home after sedation. Be sure to make transportation arrangements before the procedure.

What should I expect after returning home? 

Once you are home, keep the area around the bandage clean and dry. Ask your doctor when you can remove it. Do not shower or bathe until then. You will likely see some blood on the dressing. This is normal. You can then cover the wound with a bandage until it fully heals.

You may feel discomfort at the needle insertion site. This can last for several days, especially when bending over. Some people may also feel pain down the back of their leg. Mild bruising is normal. It can show up several days after the procedure.

Tell your doctor if you have any of these problems after the procedure:

  • Fever of 101 degrees Fahrenheit/38.3 degrees Celsius or higher

  • Bleeding that does not stop easily

  • Unusual discharge or severe pain at the needle insertion site

  • Any other signs or symptoms of infection

Questions to ask the health care team

Consider asking these questions before you have a bone marrow aspiration or biopsy:

  • Who will do the procedure?

  • What will happen during the procedure?

  • How long will the procedure take?

  • What are the risks and benefits of having the procedure?

  • Will I be awake or asleep during the procedure?

  • Will I feel any pain during the procedure? If so, for how long? What can reduce the pain?

  • Can I take my usual medications the day of this procedure?

  • Will I need to avoid any activities after the procedure?

  • Can you tell me how to care for the wound?

  • When will I learn the results?

  • Who will explain the results to me? Will I need more tests if the results suggest cancer?

Related Resources


What Is A Bone Marrow Transplant (Stem Cell Transplant)?

Donating Bone Marrow Is Easy and Important: Here’s Why

More Information

MedlinePlus: Bone Marrow Aspiration

MedlinePlus: Bone Marrow Biopsy