Sternal tap

Alternative names
Iliac crest tap; Bone marrow aspiration

Definition
The bone marrow is the tissue that manufactures the blood cells and is in the hollow part of most bones. This test is done by suctioning some of the bone marrow for examination.

How the test is performed

The site of puncture will be cleansed with an antiseptic solution, and you will be given a local anesthetic at the area. The site may be the pelvic bone or the breastbone.

Occasionally, another bone is selected. Then, a thin aspirating needle (a needle with a syringe attached that will create a suction) is inserted, and a small sample of the bone marrow fluid is withdrawn. The fluid is placed on a slide for microscopic examination.

How to prepare for the test

No special preparation is necessary for this test.

Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child’s age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child’s age:

     
  • Infant test or procedure preparation (birth to 1 year)  
  • Toddler test or procedure preparation (1 to 3 years)  
  • Preschooler test or procedure preparation (3 to 6 years)  
  • Schoolage test or procedure preparation (6 to 12 years)  
  • Adolescent test or procedure preparation (12 to 18 years)

How the test will feel
There will be a prick and a slight burning sensation with the local anesthetic. Pressure may be felt as the needle is inserted into the bone. There is a sharp sucking sensation as the marrow is aspirated, which lasts for only a few moments.

Why the test is performed
This test is used to diagnose leukemia and other disorders that affect the blood. It may help determine if cancers have metastasized (spread). It is also helpful in diagnosing some types of anemia and infections.

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

What abnormal results mean

The examination of the bone marrow can help diagnose myelofibrosis, granulomas, lymphoma, cancer, anemias, causes of thrombocytopenia (low platelets), and thrombocytosis (high platelets). In addition to examination of the marrow smear, genetic studies can be performed. Different stains may help in identifying a type of cancer or anemia.

Additional conditions under which the test may be performed:

     
  • Acute lymphocytic leukemia  
  • Acute nonlymphocytic leukemia (AML)  
  • Anemia of B-12 deficiency  
  • Anemia of folate deficiency  
  • Chronic lymphocytic leukemia (CLL)  
  • Chronic myelogenous leukemia (CML)  
  • Idiopathic thrombocytopenic purpura (ITP)  
  • Macroglobulinemia of Waldenstrom  
  • Megaloblastic anemia  
  • Pernicious anemia  
  • Primary thrombocythemia  
  • Multiple myeloma

What the risks are
There may be some bleeding at the puncture site. More serious risks, such as serious bleeding or infection, are very rare.

Johns Hopkins patient information

Last revised: December 3, 2012
by Gevorg A. Poghosian, Ph.D.

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