What peripheral blood smear finding is characteristic of megaloblastic anemia?

The characteristic finding in a peripheral blood smear of megaloblastic anemia is the presence of hypersegmented neutrophils. This condition arises primarily due to deficiencies in vitamin B12 or folate, which are critical for DNA synthesis. As a result, there is impaired nuclear maturation in the myeloid cells that leads to the observable phenomenon of neutrophils exhibiting more than the typical three to five nuclear lobes.

The hypersegmentation is indicative of disturbed myeloid cell maturation and is often seen alongside other characteristic findings in megaloblastic anemia, such as large red blood cells (macrocytes) and possibly oval macrocytes. This unique morphology aids in differentiating megaloblastic anemia from other types of anemia that may present with different blood smear findings.

In contrast, hypochromic microcytes would suggest iron deficiency anemia rather than megaloblastic anemia. Normal red cell morphology implies a well-functioning hematopoietic process, which is inconsistent with the dysplastic features seen in megaloblastic anemias. Increased eosinophils would typically be observed in conditions such as allergic reactions or parasitic infections but not in megaloblastic anemia. Therefore, hypersegmented neutrophils serve as