Hypersegmented neutrophils are most characteristic of which type of anemia?

• A. Aplastic anemia
• B. Iron deficiency anemia
• C. Megaloblastic anemia
• D. Sickle cell anemia

Answer: (C)

Hypersegmented neutrophils point to disrupted DNA synthesis in developing blood cells. In megaloblastic anemia, usually from folate or vitamin B12 deficiency, DNA replication is impaired while cytoplasmic growth continues, so the nucleus maturates slowly and ends up with many lobes—neutrophils with more than the normal five lobes. This peripheral smear finding is a hallmark clue that the anemia is megaloblastic, often accompanied by macrocytosis and sometimes glossitis.

Other common anemias don’t show this pattern: aplastic anemia involves overall bone marrow failure with low cell counts but not characteristic hypersegmentation; iron deficiency anemia features microcytosis and hypochromia rather than hypersegmented neutrophils; and sickle cell anemia is defined by abnormal hemoglobin leading to sickled red cells, not hypersegmented neutrophils.