Which term describes variability in red blood cell size?

Which term describes variability in red blood cell size?

• A. Poikilocytosis
• B. Rouleaux
• C. Polychromasia
• D. Anisocytosis

Answer: (D)

Variability in red blood cell size is described by anisocytosis. Anisocytosis means the RBCs vary in size, including the presence of smaller cells (microcytes) and larger cells (macrocytes). Clinically this variation is often quantified by the red cell distribution width (RDW) on a complete blood count. The other terms describe different features. Poikilocytosis refers to variation in shape, not size, such as elongated or irregularly shaped cells. Rouleaux describes RBCs stacking like coins due to plasma protein effects, not their size. Polychromasia indicates color variation from immature, reticulated red cells, reflecting increased production rather than size differences. So the correct term for variance in RBC size is anisocytosis.

Variability in red blood cell size is described by anisocytosis. Anisocytosis means the RBCs vary in size, including the presence of smaller cells (microcytes) and larger cells (macrocytes). Clinically this variation is often quantified by the red cell distribution width (RDW) on a complete blood count.

The other terms describe different features. Poikilocytosis refers to variation in shape, not size, such as elongated or irregularly shaped cells. Rouleaux describes RBCs stacking like coins due to plasma protein effects, not their size. Polychromasia indicates color variation from immature, reticulated red cells, reflecting increased production rather than size differences.

So the correct term for variance in RBC size is anisocytosis.