Megaloblastic Anemia

Megaloblastic Anemia are a heterogeneous group of disorders that share common morphologic characteristics.

  • Erythrocytes are larger & have higher nuclear-to-cytoplasmic ratios compared to normal cells
  • Neutrophils can be hypersegmented
  • Megakaryocytes are abnormal

On the cellular level in megaloblastic cells, the maturation of nucleus is delayed, while cytoplasmic development is normal & is characterized by sizable red blood cells. This malformation causes the bone marrow to produce fewer cells, & sometimes the cells die earlier than the normal 120-day life expectancy. In lieu of being round or disc-shaped, the red blood cells can be oval.

Megaloblastic anemia is an anemia that results from inhibition of DNA synthesis in red blood cell production. When DNA synthesis is impaired, the cell cycle cannot progress from the G2 growth stage to the mitosis (M) stage. This leads to continuing cell growth without division, which presents as macrocytosis.