Bone Marrow Aspiration and Biopsy

Definition

Bone marrow, the soft tissue contained in the medullary canals of long bone and the interstices of cancellous bone, may be removed by aspiration or needle biopsy under local anesthesia. In aspiration biopsy, a fluid specimen in which pustulae of marrow is suspended is removed. In needle biopsy, a core of marrows – cells, not fluid – its removed. These methods are commonly used concurrently to obtain the best possible marrow specimens. Red marrow, which constitutes about 50% of an adult’s marrow, actively producesstem cells that ultimately evolve into red blood cells, white blood cells and platelets. Yellow marrow contains fat cells andconnective tissue and is inactive, but it can become active in response to the body’s needs.

Bleeding and infection may result from bone marrow biopsy at any site, but the most serious complications occur at the sternum. Such complications are rare but include puncture of the heart and major vessels, causing severe hemorrhage, and puncture of the mediastinum, causing mediastinitis of pneumomediastinum.

Purpose

• To diagnose thrombocytopenia, leukemia, granulomas, anemias, and primary and metastatic tumors.
• To determine the causes of infection.
• To help stage disease such as with Hodgin’s disease.
• To evaluate chemotherapy.
• To monitor myelosuppression.

Procedure

Patient Preparation

1. Explain the procedure to the patient. A mild sedative will be given 1 hour before the test, if ordered.
2. Tell the patient the test usually takes only 5 to 10 minutes and that more than one bone marrow specimen may be required.
3. Let him know a blood sample will be collected before the biopsy for laboratory testing.
4. Make sure the patient has signed a consent form.
5. Check the patient for hypersensitivity to the local anesthetic.
6. After confirming with the doctor, tell the patient which bone- sternum, anterior or posterior iliac crest, vertebral spinous process, ribs, or tibia – will be used as the biopsy site.

Implementation

Aspiration Biopsy

1. The doctor prepares the biopsy site and injects a local anesthetic. He then inserts the needle through the skin, the subcutaneous tissue, and the cortex of the bone.
2. The doctor removes the stylet from the needle and attaches a 10 to 20 ml syringe. He aspirates 0.2 to 0.5 ml of marrow and withdraws the needle.
3. Pressure is applied to the site for 5 minutes while the marrow slides are being prepared. If the patient has thrombocytopenia, pressure is applied for 10 to 15 minutes.
4. The biopsy site is cleaned again, and a sterile adhesive bandage is applied.
5. If the doctor doesn’t obtain an adequate marrow specimen on the first attempt, he may reposition the needle or remove and reinsert it in another site within the anesthetized area. If the second attempt fails, a needle biopsy may be necessary.

Needle Biopsy

1. After preparing the biopsy site and draping the area, the examiner marks the skin at the site with an indelible pencil or marking pen.
2. A local anesthetic is then injected intradermally, subcutaneously, and at the bone’s surface.
3. The biopsy needle is inserted into the periosteum, and the needle guard is set as indicated. The needle is advanced with a steady boring motion until the outer needle passes through the bone’s cortex.
4. The inner needle with trephine tip is inserted into the outer needle. By alternately rotating the inner needle clockwise and counterclockwise, the examiner directs the needle into the marrow cavity and then removes a tissue plug.
5. The needle assembly is withdrawn, and the marrow is expelled into a labeled bottle containing Zenker’s acetic acid solution.
6. After the biopsy site is cleaned, a sterile adhesive bandage or a pressure dressing is applied.

Nursing Interventions

1. While the marrow slides are being prepared, apply pressure to the biopsy site until bleeding stops.
2. Clean the biopsy site and apply a sterile dressing.
3. Monitor the patient’s vital signs and the biopsy site for signs and symptoms of infection.

Interpretation

Normal Results

1. Yellow marrow contains fat cells and connective tissue.
2. Red marrow contains hematopoietic cells, fat cells, and connective tissue.
3. The iron satin, which measures hemosiderin (storage iron), has a +2 level.
4. The sudan black B satin, which shows granulocytes is negative.
5. The periodic acid-Schiff (PAS) stain, which detects glycogen reactions, is negative.

Abnormal Results

1. Decreased hemosiderin levels in an iron stain may indicate a true iron deficiency.
2. Increased hemosiderin levels may suggest other types of anemias or blood disorders.
3. A positive stain can differentiate acute myelogenous leukemia from acute lymphoblastic leukemia (negative stain).
4. A positive stain may also suggest granulation in myeloblasts.
5. A positive PAS stain may suggest acute or chronic lymphocyte leukemia, amyloidosis, thalasemia, lymphoma, infectious mononucleosis, iron-deficiency anemia, or sideroblastic anemia.

Complications

1. Hemorrhage and infection
2. Puncture of the mediastinum (sternum)

Precautions

• Know that bone marrow biopsy is contraindicated in the patient with a severe bleeding disorder.
• Send the tissue specimen or slide to the laboratory immediately.

Interfering Factors

• Failure to obtain a representative specimen.
• Failure to use a fixative for histologic analysis.

image courtesy of: allhealthrefer