What is the role of bone marrow biopsy in the workup of macrocytosis?

Updated: Dec 16, 2020
  • Author: Vincent E Herrin, MD, FACP; Chief Editor: Emmanuel C Besa, MD  more...
  • Print

Bone marrow biopsy and aspiration are performed to determine whether the marrow is functioning adequately and also may reveal replacement of marrow with tumor, granuloma, or fibrosis. The bone marrow should be obtained before any vitamin B12 or folate therapy or blood transfusion because megaloblastic changes may reverse rapidly.

The bone marrow in megaloblastic anemias is usually hypercellular, with all cell lines proliferating. Marked erythroid hyperplasia may occur to the point at which the myeloid-erythroid ratio is reversed. Nuclear-chromatin dissociation with a young-appearing nucleus and abundant mature-appearing cytoplasm may occur. Granulocytic hyperplasia with giant metamyelocytes and bands is often noted.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!