Bone Marrow Aspiration and Trephine Biopsy Part 1

Procedure for Bone Marrow

1. This procedure can be done as an outdoor procedure.
   1. Children and patient in tension need mild sedative prior to the procedure.
   2. If there are hairs then shave the area.
   3. Wash with the soap then clean with the antiseptic.
   4. Drap the area with sterile cloth.
2. Bone marrow aspiration is done on the patient under the local analgesia.
   1. 1 to 2% Xylocaine is injected locally.
   2. Go deep to infiltrate the periosteum of the bone.
   3. A small 3 mm incision may be made to pierce the skin and subcutaneous tissue easily.
   4. Adult size Jamshidi needle is needed.
      1. It is the 11-gauge x 4-inch length
   5. Penetrate the bone and when entering the marrow cavity then take out the stylet.
   6. Now attach the syringe (20 to 50 ml size), and suck the marrow, the patient will feel sharp pain which indicates that you are in the marrow cavity.
   7. Get 1 to 1.5 mL of the marrow particles.
      1. The marrow tissue is seen as grey particles floating in the blood and fat droplets.
      2. More sample may be aspirated for the flow cytometry, chromosomes studies, for culture and other tests.
   8. immediately make the smears before the blood clots.
      1. You make slide by putting one drop on one slide and spread it by another slide.

3. The clotted sample is put into fixative (10% buffered formalin) and this used for the sections.

4. The most common site is the Posterior Iliac crest (pelvis).
   • Other sites are sternum and anterior iliac crest.

5. One-half to 2 ml of bone marrow is aspirated.
   1. Bone marrow aspiration is done first.
   2. Bone marrow aspiration is followed by the bone biopsy,
6. During the aspiration of marrow.
   1. liquid bone marrow is aspirated or sucked in the syringe.
   2. Then spread the sample on the slides.
   3. The patient may feel a sharp pain on suction which indicates the marrow aspiration.
7. Before the bone marrow aspiration makes the peripheral blood smear and performs the Differential count.
8. For infants, general anesthesia may be needed.

Complications

1. The needle may break.
2. There may be a hemorrhage.
3. There may be infections.
4. Rarely there may be a chronic pain at the site of bone marrow aspirate or biopsy.

Indications

1. Bone Marrow examination is done to diagnose Leukemia or myeloma.
2. Bone marrow is done to diagnose anemias e.g Megaloblastic anemia, aplastic anemia or sideroblastic anemia.
3. To find a deficient iron store by special stains (Prussian blue).
4. To rule out any infiltration of the tumors.
5. To rule out the presence of fibrosis.
6. Bone marrow did as a staging part of lymphoma.
7. In Fever due to unknown cause (PUO).
8. This can be indicated for infections.
9. In the case of thrombocytopenia.

Contraindications

1. In patients who are not cooperative.
2. The patients with a bleeding tendency or coagulation disorders.

Complications of bone marrow

1. There are chances of bleeding if the patient has an increased tendency for bleeding.
2. There are chances for the infection in the case of leukopenia.
3. The sternum is not the safe site and chances for the complication are increased.
4. There may be a sternal fracture in case of a sternal puncture.
5. Sometimes patient complains pain and tenderness at the site of the puncture.

Pathophysiology

1. Bone marrow is found in the central fatty portion of the ribs, sternum, pelvis, long bones like the femur, tibia, and humerus.
2. Bone marrow consists of differentiated and undifferentiated hematopoietic cells, Reticuloendothelial cells, and fatty tissue.
   1. These are the stem cells which differentiate into the different type of the cells in the blood.
   2. These cells after maturation gain entrance to the peripheral blood.
      

      Bone marrow maturation of the cells

3. Stages of Red cell maturation.
   1. Pronormoblast
      

      Pronormoblast structure

   2. Basophilic normoblast.
   3. Polychromatic normoblast.
      

      Basophilic normoblast

   4. Reticulocytes.
   5. Erythrocytes.
      

      Red blood cell

4. Stages of Neutrophils maturation.   
   1. Myeloblast.
      

      Myeloblast

   2. Promyelocytes.
   3. Myelocytes.
      

      Promyelocyte

   4. Metamyelocytes.
   5. Band neutrophils.

   6. Mature neutrophils or Polys.

      

      Mature neutrophil

Bone marrow evaluation shows:

1. Maturation of red blood series.
2. Maturation of white blood series.
3. Presence of megakaryocytes.
4. Myeloid/erythroid ratio.
5. Iron stores.
6. Presence or absence of granulomas.
7. Any tumor cell infiltrate.
8. Overall bone marrow activity.

B.M examination reveals the following abnormal pattern:

1. Bone marrow examination shows:
   1. RBCs shape, number, and size.
   2. White blood cells shapes, size, and number.
   3. Megakaryocytes and platelets formation.
   4. Evaluate cellularity, fibrosis, and infiltrate.
   5. Estimation of iron contents.
2. The presence or absence and ratio of cells are characteristic of the suspected disease.
3. Multiple myeloma, Plasma cell myeloma, and macroglobulinemia.
4. Chronic or acute leukemia.
5. Anemia,e.g. Megaloblastic, macrocytic and normocytic anemia.
6. Toxic states that produce bone marrow depression or destruction.
7. Neoplastic conditions where the bone marrow is involved with metastatic carcinoma, lymphoproliferative diseases.
8. Platelets dysfunctions.
9. Some types of infections like Tuberculosis and Histoplasmosis.
10. Lipid or glycogen storage disease.
11. Deficiency of Iron stores like microcytic anemia.
    1. Prussian blue stain on bone marrow slides shows iron contents.

Normal Bone Marrow Components

Type of cells	Percentage % of cells in Bone Marrow	Percentage % of cells in peripheral blood
Myeloblast	3 to 5 %	0
Promyelocytes	1 to 8 %	0
Myelocytes neutrophils	5 to 19 %	0
Myelocytes eosinophils	0.5 to 3 %	0
Myelocytes basophils	0 to 0.5 %	0
Metamyelocytes	17 to 33 %	0
Neutrophils	11 to 33 %	40 to 70
Monocytes	0 to 3 %	2 to 10
Lymphocytes	8 to 20 %	20 to 40
Megakaryocytes	0 to 3 %	0
Plasma cells	0 to 2.0 %	0
Myeloid / Erythroid ratio	2: 1  to 4: 1

• M: E ratio in infection may be 6:1 and in leukemia 25:1.
• Hypercellular or hyperplasia of marrow refers to an increase in one or more cell components. This may be due to compensation or leukemic process.
• Hypocellular or hypoplasia of marrow is due to loss of cellularity or incomplete development in one or more lines of the cells.

Abnormal bone marrow findings are seen in:

1. Infections:
   1. Viral.
   2. bacterial.
   3. Fungal.
2. Chronic inflammatory diseases.
3. Myelofibrosis.
4. Agranulocytosis.
5. Malignancy:
   1. Multiple myelomas.
   2. Hodgkin’s lymphoma.
   3. Lymphoma.
   4. Polycythemia vera.
   5. Leukemias.
6. Anemias.
7. AIDS.
8. Rheumatic fever.

Difference between bone marrow aspiration and trephine biopsy:

Feature	Bone marrow aspiration	Bone marrow trephine biopsy
Site	Posterior iliac crest, sternum.	Posterior iliac crest.
Indication	Anemia, pancytopenia, neutropenia, thrombocytopenia, a possible cause of leukemia and myeloma.	Polycythemia vera, myelofibrosis, myeloproliferative disorder, aplastic anemia, lymphomas, metastatic infiltrate, splenomegaly,  PUO, and in case of a dry tap.
Information and purpose	1. Assess cytomorphology. 2. Perform a differential count. 3. Find M: E ratio. 4. It can perform cytochemical stains.	1. To assess cellularity. 2. To appreciate different cellular elements. 3. To assess the fibrosis. 4. To assess the infiltration by the tumors. 5. To evaluate bony trabeculae. 6. If in saline then can do flow cytometry. 7. If in formalin then perform immunohistochemical stains. 8. Can do T – cell and B – cell rearrangements by PCR.
Possible studies	Cytogenetics, culture, biochemical analysis, cytochemical marker, immunological studies, genetic abnormality studies by DNA, and RNA analysis.	Immunological studies and stains
Staining procedure	Romanosky, Giemsa. Prussian blue stain for iron.	Hematoxylin and eosin stain. Reticulin stain.

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