Definition

A bone marrow test is used to analyze the fluid and tissue within the bone marrow, the spongy material found at the center of bones responsible for producing blood cells.

This test is helpful for diagnosing medical conditions, such as cancer, that affect blood cells or the bone marrow. It can also assess the severity of certain diseases. Bone marrow samples may reveal changes in blood cells before they appear in standard blood tests.

Indications

Doctors may recommend a bone marrow test for patients with abnormal blood test results when the cause remains unclear and a bone marrow disorder or malignancy is suspected.

Key indications for this test include:

• Identifying the cause of unusually high or low levels of red blood cells, white blood cells, or platelets
• Detecting chromosomal abnormalities or rare genetic disorders
• Confirming diagnoses of blood cancers (e.g., leukemia, lymphoma), bone marrow infections, or other marrow disorders
• Determining whether cancer has metastasized to the bone marrow from other organs
• Evaluating the recovery of bone marrow function during or after specific cancer treatments
• Monitoring disease progression to guide treatment decisions

Contraindications

Bone marrow testing is generally safe but is contraindicated in the following medical conditions:

• Severe hemophilia, where blood clotting is significantly impaired
• Severe disseminated intravascular coagulation (DIC), which causes abnormal bleeding throughout the body
• Other severe bleeding disorders

Preparation Prior to Test

Special preparation is usually unnecessary for a bone marrow test. However, inform your doctor about all medications, vitamins, or supplements you are taking. Share details about your medical history, such as allergies, bleeding disorders, or pregnancy, to ensure the procedure is safe for you.

Test Procedure

A bone marrow test typically involves two steps:

1. Bone marrow aspiration, where a sample of bone marrow fluid is extracted.
2. Bone marrow biopsy, where a small piece of bone tissue containing marrow is removed.

Samples are commonly taken from the back of the hip bone but may be taken from the lower leg bones in children under two years old. The area for the sample collection is cleaned with antiseptic, and a local anesthetic is administered to minimize discomfort.

Using a specialized needle, the doctor retrieves the fluid and tissue samples, which can be taken simultaneously. Afterward, any bleeding is controlled, and mild bone pain may occur temporarily. Your doctor may recommend pain relievers if needed.

The collected samples are examined under a microscope in a pathology lab to identify abnormalities. Depending on the complexity of the test, results may take several days or weeks, such as in the case of chromosome analysis.

Normal and Abnormal Values

Bone marrow testing evaluates the types and quantities of blood cells, including:

• The maturity of blood cells
• The presence of abnormal cells, such as cancer cells or infectious microbes
• Structural changes in the bone or bone marrow

Results are assessed against normal ranges, which vary by age and specific health conditions. The doctor will interpret the findings in the context of your current medical condition and other test results.

Results and Recommendations (Follow-up Tests)

The results of a bone marrow test are considered normal if the number and type of blood cells, fat cells, and connective tissues are within the normal range, and no abnormal cells are present. Conversely, the test results are deemed abnormal if cancer cells, signs of infection, or structural abnormalities in the bone marrow are detected.

In addition to standard microscopic examination, specialized tests may be conducted depending on the suspected disease and the patient’s condition. These include:

• Cytochemistry (flow cytometry and immunophenotyping)
• Chromosomal studies
• Molecular tests to help classify cancer subtypes and molecular characteristics, aiding in personalized treatment planning.
• Bacterial culture and staining to identify viruses, bacteria, or fungi causing infections.

Further tests will depend on the diagnosis and treatment plan recommended by your doctor.

Consult the Right Doctor

Bone marrow test results should be reviewed by an internal medicine specialist, particularly a hematologist or oncologist. The doctor will thoroughly assess the results, confirm the diagnosis, and recommend any additional necessary tests.

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