Overview
Bone Marrow Biopsy (BMB) is a crucial diagnostic procedure in hematology that involves obtaining both aspirate and trephine biopsy specimens from the bone marrow. This procedure is essential for diagnosing various hematological disorders including leukemia, lymphoma, myelodysplastic syndromes, aplastic anemia, and metastatic malignancies. The procedure combines bone marrow aspiration (BMA) for cytological examination and trephine biopsy for histological assessment, providing complementary diagnostic information.
Bone marrow examination is the gold standard for evaluating hematopoiesis and diagnosing primary and secondary bone marrow disorders. It provides critical information about cellularity, morphology, immunophenotype, and molecular characteristics of hematopoietic cells. The procedure is particularly valuable in staging lymphomas, monitoring treatment response, and evaluating unexplained cytopenias or leukocytosis. Modern techniques allow for comprehensive evaluation including flow cytometry, cytogenetics, and molecular studies.
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Indications
Evaluation of anemia, thrombocytopenia, or leukopenia of unknown etiology
Diagnosis and staging of leukemia, lymphoma, and multiple myeloma
Assessment of dysplastic changes and cellularity in suspected MDS
Evaluation of bone marrow involvement by solid tumors
Investigation of suspected hematological causes of FUO
Assessment of treatment response in hematological disorders
Contraindications
Absolute Contraindications
Relative Contraindications
📋 Equipment Checklist
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Pre-procedure Preparation
Patient preparation includes obtaining informed consent, reviewing coagulation parameters (platelets >50,000, INR <1.5), and ensuring adequate pain control. The patient should be positioned comfortably, typically in lateral decubitus position for posterior iliac crest biopsy. Local anesthesia with lidocaine is administered, and conscious sedation may be considered for anxious patients. The skin over the posterior iliac crest is cleaned with antiseptic solution and draped sterilely.Step-by-Step Procedure
Step 1: Patient Positioning and Site Preparation
Position the patient in lateral decubitus position with the side to be biopsied uppermost. Flex the knees slightly and place a pillow between the legs for comfort. Identify the posterior iliac crest as the landmark - it is located 2-3 cm lateral to the midline and 2-3 cm below the iliac crest. Clean the skin with antiseptic solution in a circular motion, starting from the center and moving outward. Allow the antiseptic to dry completely.
⚠️ Common Mistakes to Avoid:
- Incorrect positioning leading to difficult access to the iliac crest
- Not allowing antiseptic to dry, which can contaminate the specimen
- Inadequate skin preparation increasing infection risk
💡 Pro Tip:
For obese patients, use the anterior iliac crest as an alternative site. The landmark is 2-3 cm medial to the anterior superior iliac spine.
Step 2: Local Anesthesia Administration
Using a 25-gauge needle, create a skin wheal with 1% lidocaine at the planned entry site. Then, using a 22-gauge needle, infiltrate the subcutaneous tissue and periosteum with 2-3 mL of 1% lidocaine. Wait 2-3 minutes for the anesthetic to take effect. Test the area with a needle prick to ensure adequate anesthesia before proceeding.
⚠️ Common Mistakes to Avoid:
- Inadequate anesthesia causing patient discomfort and movement
- Not waiting for anesthetic to take effect
- Insufficient infiltration of the periosteum
💡 Pro Tip:
For anxious patients, consider adding a small amount of sodium bicarbonate to the lidocaine to reduce the burning sensation.
Step 3: Bone Marrow Aspiration
Make a small skin incision (2-3 mm) with a scalpel blade. Insert the aspiration needle perpendicular to the bone surface with a gentle rotating motion. Once the needle tip contacts the bone, apply firm pressure while rotating clockwise and counterclockwise. You will feel a "give" when the needle enters the marrow cavity. Remove the stylet and attach a 10-20 mL syringe. Apply strong negative pressure and aspirate 0.5-1.0 mL of marrow.
⚠️ Common Mistakes to Avoid:
- Applying too much pressure causing needle bending or breakage
- Aspirating too much blood, diluting the marrow sample
- Not rotating the needle, causing it to get stuck in the cortex
💡 Pro Tip:
The characteristic "give" feeling when entering the marrow cavity is crucial - if you don't feel it, you may not be in the marrow space.
Step 4: Aspirate Processing
Immediately after aspiration, express the marrow onto labeled glass slides. Place a drop near the frosted end of each slide. Quickly prepare smears using the "pull-apart" technique. For flow cytometry, rinse the syringe with EDTA solution and transfer to purple top tubes. For cytogenetics, transfer to sodium heparin tubes. Label all specimens clearly with patient details.
⚠️ Common Mistakes to Avoid:
- Delayed processing causing clotting of the aspirate
- Inadequate labeling leading to specimen mix-ups
- Not preparing enough slides for comprehensive evaluation
💡 Pro Tip:
Prepare at least 8-12 slides to ensure adequate material for morphological examination, special stains, and immunocytochemistry.
Step 5: Trephine Biopsy
Using the same skin incision, insert the trephine needle perpendicular to the bone surface. Apply firm pressure while rotating the needle clockwise and counterclockwise. Once the needle enters the marrow cavity, advance it 1-2 cm. Remove the inner stylet and advance the outer cannula over the inner needle to capture the biopsy. Rotate the needle 360 degrees to separate the biopsy from surrounding bone.
⚠️ Common Mistakes to Avoid:
- Insufficient rotation causing incomplete biopsy separation
- Advancing the needle too far, risking damage to adjacent structures
- Not maintaining perpendicular orientation to the bone surface
💡 Pro Tip:
The biopsy should be 1-2 cm in length and have a characteristic "worm-like" appearance when properly obtained.
Step 6: Biopsy Extraction and Processing
Withdraw the trephine needle with a gentle rotating motion. Use a probe to gently push the biopsy specimen out of the needle. Place the biopsy immediately in 10% neutral buffered formalin. Measure the biopsy length and document it. The specimen should be processed for routine histology with H&E staining and special stains as indicated.
⚠️ Common Mistakes to Avoid:
- Forceful extraction causing biopsy fragmentation
- Delayed fixation causing autolysis
- Inadequate documentation of biopsy length
💡 Pro Tip:
Adequate biopsy length (>1 cm) is crucial for accurate assessment of cellularity and architecture.
Step 7: Hemostasis and Dressing
Apply firm pressure to the biopsy site for 10-15 minutes using sterile gauze. Check for adequate hemostasis before applying a sterile dressing. Document the procedure in the patient's chart including the site, number of aspirations and biopsies obtained, and any complications. Provide post-procedure instructions to the patient.
⚠️ Common Mistakes to Avoid:
- Insufficient pressure application leading to hematoma formation
- Inadequate documentation of the procedure
- Not providing clear post-procedure instructions
💡 Pro Tip:
Patients should be observed for at least 30 minutes post-procedure to monitor for complications.
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Post-procedure Care
Post-procedure care involves applying pressure to the biopsy site for 10-15 minutes to prevent hematoma formation. Patients should be observed for 30-60 minutes for any immediate complications. Instructions include keeping the site clean and dry for 24-48 hours, avoiding strenuous activity for 24-48 hours, and watching for signs of infection or excessive bleeding. Most patients can resume normal activities within 24-48 hours, though some may experience local discomfort for several days.Complications & Management
| Complication | Incidence | Signs | Management | Prevention |
|---|---|---|---|---|
| Hematoma | 2-5% | Swelling, pain, discoloration at biopsy site | Apply ice pack, analgesics, observation for 24-48 hours | Adequate pressure post-procedure, correct coagulation parameters |
| Infection | <1% | Erythema, warmth, purulent discharge after 24-48 hours | Antibiotics based on culture, local wound care | Strict aseptic technique, avoid biopsy through infected skin |
| Pain | 10-20% | Local discomfort lasting 24-72 hours | Analgesics (acetaminophen, NSAIDs), local ice application | Adequate local anesthesia, gentle technique |
| Fracture | <0.1% | Severe pain, deformity, inability to bear weight | Immediate orthopedic consultation, X-ray evaluation | Gentle technique, avoid excessive force, consider osteoporosis |
| Nerve injury | <0.1% | Numbness, tingling, weakness in the lower extremity | Neurological evaluation, MRI if indicated | Correct anatomical landmarks, avoid lateral deviation |
Clinical Pearls
Always perform aspiration before biopsy to avoid contamination of the aspirate with blood from the biopsy site.
The posterior iliac crest is the preferred site because it contains the most active marrow and is easily accessible.
For patients with severe thrombocytopenia, consider platelet transfusion 1-2 hours before the procedure to reduce bleeding risk.
Always document the biopsy length - adequacy criteria require at least 1.5 cm for accurate cellularity assessment.
Prepare both air-dried and alcohol-fixed smears for optimal morphological evaluation and special stains.
For suspected lymphoma, always save material for flow cytometry and molecular studies in addition to routine examination.
In patients with suspected myelofibrosis, the biopsy may be the only diagnostic material as aspiration often yields a "dry tap".