Definition
Bone Marrow Aspiration (BMA) is a diagnostic procedure where a small amount of liquid bone marrow is withdrawn, usually from the posterior iliac crest, for examination under a microscope and other laboratory studies.
Purpose in Oncology
BMA is used to evaluate the cellular components of the marrow, which is the site of blood cell production. It is critical for:
- Diagnosis of hematologic malignancies:
- Acute leukemias (ALL, AML)
- Chronic leukemias (CML, CLL)
- Myelodysplastic syndromes (MDS)
- Multiple myeloma
- Lymphomas with marrow involvement
- Staging of cancers (e.g., lymphoma staging to assess marrow infiltration)
- Monitoring treatment response or disease relapse
- Assessing marrow function after chemotherapy or stem cell transplant
Procedure Overview
- Site: Most commonly posterior superior iliac spine; sternum sometimes for aspiration only (no biopsy).
- Anesthesia: Local anesthetic ± conscious sedation.
- Aspiration: A special needle withdraws marrow fluid; sometimes followed by a core biopsy for architecture evaluation.
- Processing: Smears, flow cytometry, cytogenetics, molecular testing.
Advantages
- Relatively quick (15–30 minutes)
- Can provide detailed cytology and molecular data
- Minimally invasive compared to surgical biopsies
Limitations & Risks
- Does not assess marrow architecture (requires biopsy for that)
- Possible discomfort or pain during aspiration
- Small risk of bleeding, infection
Oncology Pharmacist Perspective
- Why relevant: BMA results guide chemotherapy selection, dosing intensity, and prognosis.
- Example: Detecting persistent blasts after induction chemotherapy in AML may prompt a change in regimen.
- Monitoring toxicity: In patients with prolonged cytopenias, BMA can differentiate chemotherapy-induced aplasia from disease relapse.