Bone marrow is the soft tissue inside bones that helps form blood cells. It is found in the hollow part of most bones. Bone marrow aspiration is the removal of a small amount of this tissue in liquid form for examination.
Bone marrow aspiration is not the same as bone marrow biopsy. A biopsy removes a core of bone tissue for examination.
How the Test is Performed
Bone marrow aspiration may be done in the health care provider's office or in a hospital. The bone marrow is removed from your pelvic or breast bone. Sometimes, another bone is selected.
Marrow is removed in the following steps:
- If needed, you are given medicine to help you relax.
- The provider cleans the skin and injects numbing medicine into the area and surface of the bone.
- A special needle is inserted into the bone. The needle has a tube attached to it, which creates suction. A small sample of bone marrow fluid flows into the tube.
- The needle is removed.
- Pressure and then a bandage are applied to the skin.
The bone marrow fluid is sent to a laboratory and examined under a microscope.
How to Prepare for the Test
Tell the provider:
- If you are allergic to any medicines
- If you are pregnant
- If you have bleeding problems
- What medicines you are taking
How the Test will Feel
You will feel a sting and slight burning sensation when the numbing medicine is applied. You may feel pressure as the needle is inserted into the bone, and a sharp and usually painful sucking sensation as the marrow is removed. This feeling lasts for only a few seconds.
Why the Test is Performed
Your doctor may order this test if you have abnormal types or numbers of red or white blood cells or platelets on a complete blood count.
This test is used to diagnose:
- Anemia (some types)
- Other blood cancers and disorders
It may help determine whether cancers have spread or responded to treatment.
The bone marrow should contain the proper number and types of:
- Blood-forming cells
- Connective tissues
- Fat cells
What Abnormal Results Mean
Abnormal results may be due to cancers of the bone marrow, including:
- Acute lymphocytic leukemia (ALL)
- Acute myelogenous leukemia (AML)
- Chronic lymphocytic leukemia (CLL)
- Chronic myelogenous leukemia (CML)
Abnormal results may also be due to other causes, such as:
- Bone marrow doesn't make enough blood cells (aplastic anemia)
- Bacterial or fungal infections that have spread throughout the body
- Cancer of the lymph tissue (Hodgkin or non-Hodgkin lymphoma)
- A bleeding disorder called idiopathic thrombocytopenic purpura (ITP)
- Blood cancer called (multiple myeloma)
- Disorder in which the bone marrow is replaced by scar tissue (myelofibrosis)
- Disorder in which the bone marrow produces too many red blood cells (polycythemia) or platelets (thrombocytosis)
- Disorder in which not enough healthy blood cells are made (myelodysplastic syndrome; MDS)
There may be some bleeding at the puncture site. More serious risks, such as serious bleeding or infection, are very rare.
Iliac crest tap; Sternal tap; Leukemia - bone marrow aspiration; Aplastic anemia - bone marrow aspiration; Myelodysplastic syndrome - bone marrow aspiration; Thrombocytopenia - bone marrow aspiration; Myelofibrosis - bone marrow aspiration
Bates I, Burthem J. Bone marrow biopsy. In: Bain BJ, Bates I, Laffan MA, eds. Dacie and Lewis Practical Haematology. 12th ed. Philadelphia, PA: Elsevier; 2017:chap 7.
Chernecky CC, Berger BJ. Bone marrow aspiration analysis -- specimen (biopsy, bone marrow iron stain, iron stain, bone marrow). In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:241-244.
Choby BA. Bone marrow aspiration and biopsy. In: Fowler GC, ed. Pfenninger and Fowler's Procedures for Primary Care. 4th ed. Philadelphia, PA: Elsevier; 2020:chap 220.
Vajpayee N, Graham SS, Bem S. Basic examination of blood and bone marrow. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 31.
Review Date 4/29/2022
Updated by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.