Bone Marrow Biopsy and Aspiration

Pediatric Bone Marrow Biopsy and Aspiration

Key Points

Essential diagnostic procedure in pediatric hematology-oncology
Requires appropriate sedation/anesthesia in children
Different needle sizes based on patient age/size
Multiple specimens often needed for comprehensive evaluation
Proper specimen handling crucial for accurate diagnosis

Definition

Bone marrow examination consists of aspiration of bone marrow fluid and/or core biopsy of bone marrow tissue. This procedure provides essential information about bone marrow cellularity, maturation, and possible infiltration by abnormal cells.

Primary Indications

Diagnosis and Staging:
- Leukemia/lymphoma
- Solid tumor metastases
- Langerhans cell histiocytosis
- Hemophagocytic lymphohistiocytosis
Hematologic Disorders:
- Unexplained cytopenias
- Pancytopenia
- Bone marrow failure syndromes
- Storage disorders
Treatment Monitoring:
- Response assessment
- Minimal residual disease testing
- Post-treatment evaluation
- Pre-transplant assessment

Pre-Procedure Assessment

Laboratory Studies:
- Complete blood count
- Coagulation profile
- Platelet count
Patient Factors:
- Age and size
- Previous procedure experience
- Anatomical considerations
- Anxiety level
Anesthesia/Sedation Planning:
- NPO status verification
- Anesthesia risk assessment
- Selection of appropriate method

Essential Equipment

Sterile Equipment:
- Bone marrow needles (sizes based on age):
  - Infants: 18G
  - Children: 15-16G
  - Adolescents: 11-13G
- Aspiration syringes (10-20mL)
- Biopsy needles
- Sterile drapes and gauze
Collection Materials:
- EDTA tubes
- Specimen containers with fixative
- Slides for smears
- Culture bottles if needed
Additional Items:
- Local anesthetic
- Antiseptic solution
- Dressing materials
- Pain medications

Procedure Steps

Patient Positioning
- Posterior iliac crest approach:
  - Lateral decubitus position
  - Hip flexed, upper knee bent
- Anterior iliac crest approach:
  - Supine position
  - Small roll under hip
Site Preparation
- Identify anatomical landmarks
- Mark site
- Sterile prep and drape
- Local anesthetic infiltration
Aspiration Technique
- Insert needle through periosteum
- Remove stylet
- Attach syringe
- Rapid aspiration (1-2mL)
- Prepare slides immediately
Biopsy Technique
- Insert biopsy needle
- Advance with rotating motion
- Capture core specimen
- Gentle removal
- Place in fixative

Potential Complications

Immediate:
- Excessive bleeding
- Pain
- Vasovagal reactions
- Needle breakage
Delayed:
- Infection
- Persistent pain
- Hematoma formation
- Site numbness

Prevention Strategies

Proper technique
Adequate sedation/anesthesia
Pressure dressing application
Post-procedure monitoring

Specimen Collection

Aspirate Specimens:
- Morphology slides
- Flow cytometry
- Cytogenetics
- Molecular studies
- Culture if indicated
Core Biopsy:
- Fixation options
- Touch preparations
- Special stains
- Immunohistochemistry

Handling Guidelines

Immediate processing of slides
Proper labeling
Transport conditions
Documentation requirements

Normal Findings

Cellularity:
- Age-appropriate ranges
- Cell line distribution
- Maturation patterns
Morphology:
- Erythroid series
- Myeloid series
- Megakaryocytes
- Stromal elements

Pathological Findings

Malignant Conditions:
- Leukemia blast percentage
- Lymphoma involvement
- Metastatic disease
Non-Malignant Conditions:
- Aplasia
- Dysplasia
- Storage diseases
- Fibrosis