A bone marrow examination, which typically includes both an aspiration and a biopsy, is a highly specialized and informative diagnostic procedure that provides your doctor with a direct sample of your bone marrow. The bone marrow is the soft, spongy tissue found inside your larger bones that functions as the body's primary factory for producing all blood cells. This procedure is essential for diagnosing, staging, and monitoring a wide variety of diseases, including blood cancers like leukemia and lymphoma, as well as conditions involving bone marrow failure, such as aplastic anemia. By obtaining these samples, hematologists and pathologists can meticulously examine the quantity, quality, and maturity of developing blood cells, look for abnormal or cancerous cells, and perform advanced genetic and molecular tests.

While the thought of a bone marrow procedure can cause apprehension, it is a routine and safe test performed by a specialist under local anesthesia to ensure you are as comfortable as possible. The information gained from a bone marrow exam is invaluable and often cannot be obtained through any other test.

It provides a definitive diagnosis that is critical for formulating the correct treatment plan, offering patients the best possible path toward recovery and health. This comprehensive guide will explain the science of your bone marrow, why this test is necessary, what to expect during every step of the procedure, and how the samples are analyzed to provide life-saving answers.

Understanding Bone Marrow: The Body's Blood Factory

To understand why a bone marrow examination is so crucial, it is important to first understand the vital role this tissue plays. Your bone marrow is the manufacturing center for your entire blood and immune system, a process known as hematopoiesis.

What is Bone Marrow?

Located in the center of your larger bones, such as the hip bones, sternum, and vertebrae, bone marrow exists in two forms. Red marrow is the site of active blood cell production, while yellow marrow is primarily composed of fat. A bone marrow procedure samples the active red marrow.

Hematopoiesis: The Creation of Blood

The entire process of blood formation begins with a single, remarkable type of cell: the Hematopoietic Stem Cell (HSC). These are the mother cells of the blood system, capable of both self-renewal and differentiating into all the various types of mature blood cells. The HSC gives rise to two major cell lines:

The Myeloid Cell Line: This line is responsible for producing:

• Red Blood Cells (Erythrocytes): These cells contain hemoglobin and are responsible for carrying oxygen throughout your body.
• Platelets (Thrombocytes): These small cell fragments are essential for blood clotting and preventing bleeding.
• Granulocytes: A type of white blood cell that fights infection, including neutrophils, eosinophils, and basophils.

The Lymphoid Cell Line: This line produces another critical type of white blood cell:

• Lymphocytes: These cells (B-cells and T-cells) are the cornerstones of your adaptive immune system, responsible for producing antibodies and coordinating the immune response.

A bone marrow examination allows your doctor to assess the health of this entire factory. They can see if the factory is working correctly, if it's underproducing, overproducing, or producing defective or cancerous cells.

When is a Bone Marrow Exam Recommended?

Your doctor, usually a hematologist or oncologist, will recommend a bone marrow biopsy and aspiration when a blood test or your clinical symptoms suggest a problem that originates in the bone marrow. It is a definitive step in diagnosing and managing many serious conditions.

Diagnosing Cancers of the Blood and Marrow

• Leukemia: A bone marrow exam is the definitive test to diagnose both acute and chronic leukemias. It identifies the presence and type of cancerous white blood cells and determines how much of the normal marrow has been replaced by cancer.
• Lymphoma: For patients diagnosed with lymphoma (a cancer of the lymphocytes), a bone marrow exam is often used for staging, to determine if the cancer has spread to the bone marrow.
• Multiple Myeloma: This is a cancer of the plasma cells, a type of B-lymphocyte. A bone marrow biopsy is essential to confirm the diagnosis by showing an abnormally high percentage of plasma cells.

Investigating Abnormal Blood Counts

• Anemias and Low Blood Counts: When you have unexplained, severe anemia (low red blood cells), thrombocytopenia (low platelets), or leukopenia (low white blood cells), a bone marrow exam can determine if the problem is due to a failure of production within the marrow.
• Pancytopenia: This is a condition where all three blood cell lines are low. A bone marrow exam is critical to diagnose the cause, such as Aplastic Anemia, a rare but serious condition where the bone marrow fails to produce enough blood cells.

Diagnosing Other Marrow Disorders

• Myelodysplastic Syndromes (MDS): Often called pre-leukemia, these are a group of disorders where the bone marrow produces blood cells that are defective and do not mature properly.
• Myeloproliferative Neoplasms (MPNs): These are conditions where the bone marrow overproduces one or more types of blood cells. Examples include Polycythemia Vera (too many red cells) and Essential Thrombocythemia (too many platelets).

Other Indications

• Staging of Solid Tumors: To check if other cancers, like breast, lung, or prostate cancer, have metastasized (spread) to the bone marrow.
• Investigating a Fever of Unknown Origin (FUO): In some cases, a bone marrow exam can help identify hidden infections or other causes of a persistent fever.

The Procedure: A Detailed, Reassuring Walkthrough

The thought of this procedure can cause anxiety, but understanding each step can help alleviate fear. It is almost always performed as an outpatient procedure. It involves two parts, usually done in quick succession through the same entry point.

The Difference Between Aspiration and Biopsy:

• Aspiration: This part of the procedure collects a sample of the liquid portion of the bone marrow. This is ideal for looking at the individual types and shapes of the cells.
• Biopsy: This part collects a small, solid core sample of the spongy bone marrow tissue. This provides a view of the marrow's overall structure, cellularity (how full or empty the marrow is), and how the cells are arranged.

Preparation for the Procedure

• Consultation: Your doctor will explain why the test is needed, what it involves, and will answer all your questions.
• Blood Tests: You will have routine blood tests done beforehand to check your blood counts and clotting function.
• Medication Review: You must inform your doctor of all medications you are taking, especially blood thinners like aspirin, clopidogrel, or warfarin, as you may need to stop them for a period before the test.
• Sedation: The procedure is typically done under local anesthesia. However, you can discuss the option of conscious sedation (an IV medication that makes you very relaxed and sleepy) with your doctor to minimize anxiety and discomfort. If you opt for sedation, you will need someone to drive you home.

The Step-by-Step Process

The entire procedure usually takes about 30 minutes. The most common site for the procedure is the posterior iliac crest, which is the back of your hip bone. It is not taken from your spine or spinal cord.

• Positioning: You will be asked to lie on your stomach or on your side, with your back curved.
• Numbing the Area: This is the most critical step for your comfort. The doctor will first clean the skin over your hip with an antiseptic solution. They will then inject a local anesthetic into the skin and deeper tissues using a very fine needle. You will feel a brief sting, followed by a burning sensation as the anesthetic works. The doctor will wait a few minutes to ensure the area, including the sensitive surface of the bone (the periosteum), is thoroughly numb.
• The Aspiration: The doctor will make a tiny incision in the numbed skin and insert the bone marrow aspiration needle through the skin and into the bone. You will feel a significant amount of pressure during this step. Once the needle is in the marrow cavity, the doctor will attach a syringe and draw back a small amount of the liquid marrow. At this moment, you will likely feel a brief but sharp, deep, pulling or cramping sensation that lasts for a few seconds. This is the most uncomfortable part of the procedure for most people.
• The Biopsy: The aspiration needle is removed, and a slightly larger biopsy needle is inserted through the same site. The doctor will use a twisting motion to collect a small, solid core of the marrow tissue. You will again feel pressure and a twisting or crunching sensation, but this is not typically painful due to the local anesthetic.
• Completion: The biopsy needle is removed. A sterile dressing is applied, and firm pressure is held on the site for several minutes to prevent bleeding.

After the Procedure

• Recovery: You will be asked to lie on your back for 10-15 minutes to help keep pressure on the site. If you have sedation, you will be monitored until you are fully awake.
• Home Care: You can typically go home shortly after. You will need to keep the dressing clean and dry for 24-48 hours. It is normal to have some soreness and aching at the site for two to three days, which can be managed with over-the-counter pain relievers like paracetamol (avoid aspirin unless cleared by your doctor). Strenuous activity should be avoided for a day or two.

In the Laboratory: What Happens to Your Sample?

The samples you provide are sent to a specialized hematopathology laboratory for detailed analysis.

The Aspirate Smear: The liquid marrow is smeared onto glass slides, stained with special dyes, and examined under a microscope by a pathologist. They will perform a differential count, identifying and counting the different types of maturing and mature blood cells to see if they are present in normal proportions.

The Biopsy Core Section: The solid tissue core is processed, embedded in wax, cut into paper-thin sections, and stained. This allows the pathologist to assess the marrow's overall architecture and cellularity (the ratio of blood-forming cells to fat).

Advanced Tests: The samples are also used for a panel of sophisticated tests:

• Flow Cytometry: A laser-based technology used on the liquid aspirate to rapidly identify and quantify different cell populations, which is essential for diagnosing and classifying leukemias and lymphomas.
• Cytogenetics (Karyotyping): This test analyzes the chromosomes within the marrow cells to look for specific abnormalities that are characteristic of certain cancers.
• Molecular Studies (FISH and PCR): These tests look for specific mutations or rearrangements in the DNA of the marrow cells, which can help in diagnosis, prognosis, and guiding targeted therapy.

Our Specialists

Bone marrow examinations are performed and interpreted by a dedicated team of hematologists and hemato-pathologists, who are experts in the diseases of the blood and bone marrow.

Dr. Niti Raizada

PRINCIPAL DIRECTOR MEDICAL ONCOLOGY | Fortis BG Road

Dr. Rahul Bhargava

PRINCIPAL DIRECTOR HEMATO-ONCOLOGY | FCI Defence Colony

Dr. Vikas Dua

PRINCIPAL DIRECTOR & HEAD - PEDIATRIC HEMATOLOGY, HEMATO ONCOLOGY & BONE MARROW TRANSPLANT | Fortis Gurgaon

Dr. Mitu Shrikhande

DIRECTOR HEMATO-ONCOLOGY & BMT | Fortis Vasant Kunj

Patient Stories

“Hearing that I needed a bone marrow biopsy to find the cause of my severe anemia was terrifying. I had read stories online that made it sound unbearable. My hematologist at Fortis was amazing; he calmly walked me through every single step and explained the option of sedation, which I chose. I barely remember the procedure itself. I had some soreness in my hip for a few days, like a deep bruise, but it was completely manageable with paracetamol. The test gave us a definitive diagnosis of aplastic anemia and allowed us to start the correct treatment immediately. Don't let fear stop you from getting the answers you need”.  — A. Sharma, 28, Delhi

“When my husband was diagnosed with multiple myeloma, the bone marrow biopsy was the test that confirmed it. The information from that one sample was incredible. It didn’t just give us the diagnosis; the advanced genetic tests run on the marrow helped the doctors understand the specific subtype of his cancer and choose a targeted therapy that has been very effective. It’s a tough procedure to think about, but the clarity it provides for a cancer treatment plan is absolutely essentia”l.  — S. Kumar, wife of a patient, Gurugram

Myths vs Facts

Take the Next Step

A bone marrow examination is a powerful diagnostic tool that provides unparalleled insight into your body's blood-forming system. While the prospect of the procedure can be daunting, the information it yields is often the key to unlocking a definitive diagnosis, understanding your prognosis, and creating the most effective and personalized treatment plan.

If your doctor has recommended this test, it is because it is the most direct and comprehensive way to get the answers needed to manage your health. Our team of expert hematologists is here to ensure the procedure is performed with the utmost skill, safety, and focus on your comfort.

CTA: Consult a Haematologist / Get a Second Opinion

Frequently Asked Questions

1. How long does the bone marrow procedure itself take?

Ans. The entire time in the procedure room is usually about 30 minutes. This includes positioning, cleaning, numbing the area, and the aspiration and biopsy themselves, which only take a few minutes each.

2. Can I drive myself home after the procedure?

Ans. If you only have a local anesthetic, you can usually drive yourself home. However, if you opt for any form of IV sedation, you absolutely must have a responsible adult to drive you home and stay with you.

3. When will I get the results?

Ans. A preliminary report based on the initial microscopic examination of the aspirate smear may be available within 24-48 hours. However, the final, complete report, which includes the results from the biopsy core and advanced tests like cytogenetics and molecular studies, can take one to two weeks.

4. What are the risks of a bone marrow exam?

Ans. It is a very safe procedure in experienced hands. The most common risk is bleeding or bruising at the site. The risk of a serious infection is very low. Damage to surrounding structures is extremely rare.

5. Is the procedure safe for children?

Ans. Yes, it is a standard procedure for children who need it. For young children, the procedure is almost always performed under general anesthesia to ensure they remain completely still and experience no discomfort.

6. Do I need to be admitted to the hospital?

Ans. No, a bone marrow biopsy and aspiration is almost always performed as an outpatient or day-care procedure. You will go home the same day.

7. How much marrow is taken out? Will my body miss it?

Ans. The amount of marrow taken is very small. The liquid aspirate is typically only about 1-2 milliliters, and the solid biopsy core is about 1-2 centimeters long and as thin as a matchstick. Your body is constantly making new marrow, and this tiny sample is replaced very quickly without you noticing.

8. Why is both an aspiration and a biopsy needed?

Ans. They provide different but complementary information. The liquid aspirate is best for looking at the detailed appearance and types of individual cells (morphology) and for tests like flow cytometry. The solid biopsy core is best for looking at the overall structure, cellularity, and architecture of the marrow factory itself. Having both gives the pathologist the complete picture.