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.

See also:

• Bone marrow biopsy
• Bone marrow culture

The bone marrow will be removed from your pelvic or breast bone. Occasionally, another bone is selected.

The health care provider will clean the skin and apply a numbing medicine (local anesthesia) to the area and surface of the bone. Next, 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.

A laboratory specialist looks at the bone marrow fluid under a microscope.

No special preparation is necessary for this test.

You may 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 sucking sensation as the marrow is removed. This feeling lasts for only a few moments.

This test is used to diagnose leukemia, infections, some types of anemia, and other blood disorders. It may help determine if cancers have spread.

The marrow should contain blood-forming (hematopoietic) cells, fat cells, and connective tissues.

Abnormal results may be due to:

• Acute lymphocytic leukemia
• Acute nonlymphocytic leukemia (AML)
• Anemia of B12 deficiency
• Anemia of folate deficiency
• Chronic lymphocytic leukemia (CLL)
• Chronic myelogenous leukemia (CML)
• Idiopathic thrombocytopenic purpura (ITP)
• Lymphoma
• Macroglobulinemia of Waldenstrom
• Megaloblastic anemia
• Multiple myeloma
• Myelofibrosis
• Pernicious anemia
• Primary thrombocytopenia

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