Bone Marrow Aspiration and Biopsy

Site

Posterior superior iliac spine is preferred to sternal aspirate

Needle:

A Jameshedi needle is more useful, as many cases will need a bone marrow biopsy (Trephine) in addition to the aspirate for diagnostic purposes.

Procedure:

The posterior superior iliac spine is easy to palpate in most of the people except in very obese individuals. Sufficient local anaesthesia can be infiltrated in the muscular as well as in the periosteal region. In obese individuals, a lumbar puncture needle can be used to reach the posterior superior iliac spine (as the spine will be deeper and you will need a lengthier needle). After 2 minutes of local infiltration, a small nick is made at the site of skin with 11G needle to pierce the skin and subcutaneous tissue. Then the bone marrow needle is gently introduced. The tip of the needle can be manipulated initially to palpate the maximal prominence of the bone. (This is more important in obese individuals). Then the needle is slowly introduced with a screw type motion. Once the needle is inside the marrow, it will not move even if you flick it with your finger. Now the stillete is removed and immediately marrow is aspirated. Don’t delay even a second, once the stillette is out. For making smears alone, 1 ml is sufficient, as taking more amount may end up in dilute marrow. The initial sample can be used to make smears and further samples may be taken with different syringes for other purposes (cytogentics etc). If you can’t aspirate initially, try aspirating using a 20 ml syringe (which should be kept ready always before any bone marrow procedure) . The aspiration should be swift to draw more particles. Even if you have to draw two to three times to collect samples for cultures, cytogenetics, PCR etc, the entire aspiration should be finished within 3-5 seconds, as marrow can clot rapidly. Once samples are obtained for making smears and for other purposes, the needle is withdrawn.

Then the same jameshedi needle can be used to do the bone biopsy. Make sure that there is no blood or clot inside the needle by inserting the stillette. Now introduce the jamshedi needle without the stillette and make few screw type movements clockwise and anti clockwise. Then remove the needle. You can see the bone piece inside the needle. Use the plunger to remove the trephine biopsy sample from the needle.

Making Smears:

As marrow samples clot immediately within few seconds, the smears should be done immediately. If the clinician is not familiar with doing smears in bone marrows, it is better to collect the initial 1 ml of the marrow in a EDTA tube and sent to the laboratory for making smears later. Otherwise, a technician by the side can be helpful to make the smears immediately. The technician should be able to drain the blood and use as much as particles as possible to make smears. It is also preferable to crush some particles in the centre of the slide and make smears.

In case, no sufficient particles are obtained, it is preferable that the bone marrow biopsy imprints are taken in multiple slides, before transferring the biopsy to the formalin container.

The samples for special tests such as flow cytometry, cytogenetics etc., should be collected in the specific tubes as specified by the concerned laboratories.

Preservation:

The bone marrow trephine sample should be put in a FAA (formalin acetic acid) solution before transferring to the laboratory. In the absence of FAA, simple formalin can be used, but the architectural details may be affected. If you need special immunohistochemistry on the marrow trephine, separate solutions are available. Contat the nearest hematology/pathology lab for details.

All the samples should reach the concerned lab as soon as possible, preferably within 24 hours.

Indications:

The indications for bone marrow aspiration and biopsy are so broad to be listed here. It is mainly a clinical decision depending on what further information, the clinician wants to get from the bone marrow. However it can be said, before proceeding with a bone marrow procedure for the first time in a patient, the peripheral blood smear should be thoroughly reviewed by a hematologist/Pathologist. This will help to elucidate possible differential diagnosis and will guide the clinician in deciding the need to collect further samples for chromosomal analysis (cytogentics) etc and also to decide whether a particular patient will need a bone marrow biopsy or not.

  • In general, if the diagnosis of leukemia is strongly suspected in the peripheral blood, bone marrow examination can be left to the centre treating leukemias. More than 50% of the cases, the diagnosis and the type of leukemia can be made from the peripheral blood itself. In all cases with suspected leukemia and in some lymphomas, the samples are taken for cytogenetics, flowcytometry, PCR and a biopsy specimen to know the type of involvement in cases of lymphoma.
  • In cases of isolated anemia, please rule out the possibility of iron deficiency and megaloblastic anemia as they may not need bone marrow examination. In fact megaloblastic anemia is the only situation where the bone marrow is not indicated even in the presence of severe pancytopenia.
  • Also please rule out the possibility of hemolytic anemias, as most cases of hemolytic anemias may not need bone marrows.
  • Isolated thrombocytopenia, is a perfect indication for proceeding with bone marrow even in peripheral centres. Even though marrow examination is not mandatory in classical ITP, in any suspected case, bone marrow aspirate and biopsy have to be done to rule out other serious disorders, such as leukemia, aplastic anemia, MDS etc. In these cases, it is better to collect further samples to avoid repeat marrows, in case the diagnosis differs. (contact the nearest hematology centre for advise in this regard)/
  • In suspected aplastic anemia, a bone marrow biopsy (trephine) is a must. As some cases may have residual bone marrow activity, which is evident in some particles, a bone marrow aspirate alone can mask a diagnosis of aplastic anemia.
  • In cases of PUO, in addition to sending aspirate samples for cultures, a bone marrow biopsy is essential to rule out granulomas
  • Most of the cases of pancytopenia in older adults may be due to myelodysplasias. Eventhough diagnosis can be made in the properly stained bone marrow aspirates, chromosomal analysis and a biopsy is essential.

As bone marrow is an invasive procedure, a careful thought will avoid multiple bone marrows in a patient just for diagnostic purposes.

 
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