Bone marrow aspiration

Bone marrow is the soft tissue inside your bones that makes blood cells. During a bone marrow aspiration, a specialist removes a small amount of this tissue in liquid form to examine it under a microscope. The test can help show whether your marrow is healthy and making the right number of blood cells. It’s a common tool used to check for blood disorders, certain types of infections, or fevers that don’t have a clear cause. Bone marrow aspiration is different from a bone marrow biopsy, which removes a small core of solid tissue instead of liquid. In many cases, both tests are done at the same time.

This procedure is typically performed by a hematologist, a specialist in blood disorders, or an oncologist, who focuses on cancer care. At Penn Medicine, you have access to one of the largest and most comprehensive hematology groups in the region. Our team works closely with other specialists across the health system, including experts in blood cancer care, to provide coordinated support.

You might need a bone marrow aspiration procedure if routine blood work shows abnormal results or if symptoms suggest a problem with your blood cells. Because bone marrow is where these cells are formed, looking at the source can provide answers that a regular blood draw cannot. It may also help show whether a condition has progressed, how well treatment is working, or if iron levels are adequate.

This test may be used to diagnose or monitor conditions like:

• Certain types of anemia
• Infections that affect the blood or bone marrow
• Blood cancers like leukemia, lymphoma, or multiple myeloma
• Other blood disorders
• Conditions where the body makes too many or too few blood cells
• Unexplained fevers

The bone marrow aspiration procedure is usually done as an outpatient visit, meaning you’ll go home the same day. The sample is typically taken from the back of the hip bone. You’ll be asked to lie on your side or stomach. The area is cleaned, and numbing medicine is injected into the skin and the surface of the bone. You may feel a brief sting or burning when the numbing medicine is given. If needed, medicine may also be given through an IV to help you relax.

Once the area is numb, a special hollow needle is inserted into the bone. A syringe attached to the needle gently pulls out a small amount of liquid marrow. You might feel pressure and a short, sharp pulling sensation when the marrow is removed. This feeling lasts only a few seconds. If a bone marrow biopsy is also planned, a small core of tissue is taken at the same visit. After the sample is collected, pressure is applied, and a bandage is placed over the site. The sample is then sent to a lab for review.

You may feel soreness at the site for a few days. Mild bruising is also common. Keep the area clean and dry for at least 24 hours, or follow the instructions provided by your care team.

Results from bone marrow tests are usually available within a few days, although some specialized studies may take longer. Your care team will explain what the test shows, what the results mean for you, and whether any follow-up tests or treatments are needed.

We know waiting for answers can feel stressful. At Penn Medicine, your bone marrow sample is reviewed by specialists within a nationally recognized program for blood disorders. Using advanced lab testing, our team works efficiently and thoughtfully to help you understand your results and what comes next.