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Size of normal red cells
7.5 micrometers(mm)in diameter
Characteristics of normal RBC
Central concavity and pallor
Variation in size of RBC's is called Anisocytosis.
Anisocytosis is encountered in
- Megaloblastic anemia
- Iron deficiency anemia
Variation in shape. Abnormal shapes of red blood cells
Poikilocytosis
- Megaloblastic anemia
- Iron deficiency anemia
Microcytic and Hypochromic : Smaller than normal with prominent central pallor
- Iron deficiency anemia Causes include: Blood loss Pregnancy Impaired GI absorption
- Beta Thalessemia
- Sideroblastic anemia
Macrocytic : Larger than normal
- Chronic hepatic disorders, i.e. cirrhosis, chronic hepatitis
- Alcoholism
- Hypothyroidism
- Megaloblastic anemia (Vitamin B12 or folate deficiencies)
- Myelodysplasia
Sickle Cells: Elongated crescentic red blood cells
- Sickle cell hemoglobinopathies (e.g.SS,SC, S-thalassemia)
- Rarely seen in sickle trait(AS)smear.
Elliptocytes: Cells are elliptical in shape.
- Hereditary elliptocytosis
- Thalassemia
- Iron Deficiency
Target Cells: Central and outer rim staining with intervening ring of pallor
- Liver disease
- Thalessemia
- Hemoglobin C disease
- Sickle cell disease
Acanthocytes: Also called Spur cells Irregularly spiculated . Dense center.
Due to altered cell membrane lipids
- Severe liver disease
- Abetalipoproteinemia
- Rarely seen in anorexia nervosa
- Malabsorption
- Post Splenectomy
Polychromatophilia: Reticulocytes: Blue hue in macrocytes
- Hemolytic anemia
- Thalassemia Major
- Autoimmune Hemolysis
- Hemorrhage
- After replacement of Iron, B12, Folate
Rouleaux Formation: Alignment of red blood cells in stacks (more than 4-5 per stack)
- Paraproteinemia as in multiple myeloma or macroglobulinemia
- High fibrinogen (inflammatory states; high ESR)
- Artifactual
Howell jolly bodies : small basophilic dense inclusion
- Post Splenectomy
- Hemolytic anemia
Spherocytes : Small hyperchromic cells lacking normal central pallor.