Bone Marrow Biopsy

Function

A Bone Marrow Biopsy involves the removal of a small solid core of bone marrow tissue (usually from the pelvic bone) to examine the architecture, cellularity, and presence of abnormal cells. Unlike an aspiration (which looks at liquid cells), the biopsy provides a 'snapshot' of the bone marrow's physical structure, showing how cells are arranged and the state of the supporting stroma.

Why it is Ordered

This procedure is the gold standard for diagnosing and staging various blood-related disorders. It is ordered when blood tests (CBC) show unexplained high or low counts, or when abnormal cells are found in the peripheral blood. Key reasons include:

• Diagnosing Leukemias and Lymphomas: Determining the type and extent of cancer.
• Unexplained Anemia or Thrombocytopenia: Finding out why the body isn't producing enough blood cells.
• Fever of Unknown Origin: Checking for infections like tuberculosis or fungal diseases in the marrow.
• Staging: Seeing if a cancer from elsewhere has spread to the bone marrow.

Associated Conditions

• Myelofibrosis: Scarring of the bone marrow.
• Aplastic Anemia: A condition where the marrow stops producing new cells.
• Myelodysplastic Syndromes (MDS): Poorly formed or dysfunctional blood cells.
• Multiple Myeloma: Cancer of the plasma cells.

Interpretation

Pathologists look for 'Cellularity' (the ratio of blood-producing cells to fat), which naturally decreases with age. They also look for 'Fibrosis' (scarring), 'Granulomas' (signs of infection), and 'Infiltration' (presence of metastatic cancer cells). The absence of blasts (immature cancer cells) and the presence of maturing erythroid, myeloid, and megakaryocytic lines indicate health.