Michelle To and Valentin Villatoro
Images show peripheral blood smears with numerous spherocytes present (examples are indicated by arrows). From MLS Collection, University of Alberta.
Image 1: 100x oil immersion. https://doi.org/10.7939/R39883320
Image 2: 50x oil immersion. https://doi.org/10.7939/R3XG9FS24
Round red blood cells that lack an area of central pallor. Cells often appear darker and smaller than a normocytic red blood cell.1
Formation of spherocytes in circulation occurs due to a partial loss of the red blood cell membrane. This can occur when RBCs are not fully phagocytosed by macrophages during extravascular hemolysis.2 Cellular content remains the same and this leads to a decrease in the surface to volume ratio and spherocyte formation.3
Hereditary Spherocytosis: the formation of spherocytes occurs due to the defects in the vertical protein linkages between the membrane and cytoskeleton, resulting in a loss of unsupported RBC membrane and spherocyte formation.4
Associated Disease/Clinical States:1,5-7
Warm Auto-Immune Hemolytic Anemia (WAIHA)
Drug-Induced Immune Hemolytic Anemia
Allo-Immune-mediated hemolysis (delayed hemolytic transfusion reactions, Hemolytic Disease of the Fetus and Newborn)
Glucose-6-Phosphate (G6PD) Deficiency
Transfused cells (storage lesion)
Note: Spherocytes have an increased MCHC (>360 g/L).5
1. Rodak BF, Carr JH. Variations in shape and distribution of erythrocytes. In: Clinical hematology atlas. 5th ed. St. Louis, Missouri: Elsevier Inc.; 2017. p. 93-106.
2. Doig K. Introduction to increased destruction of erythrocytes. In: Rodak’s hematology clinical applications and principles. 5th ed. St. Louis, Missouri: Saunders; 2015. p. 348-66.
3. Bain BJ. Morphology of blood cells. In: Blood cells: a practical guide [Internet]. 5th ed. Chichester, UK: John Wiley & Sons, Ltd; 2015 [cited 2018 Jul 10]: 67-185. Available from: http://doi.wiley.com/10.1002/9781118817322
4. Da Costa L, Galimand J, Fenneteau O, Mohandas N. Hereditary spherocytosis, elliptocytosis, and other red cell membrane disorders. Blood Rev [Internet]. 2013[cited 2018 Jul 24];27(4):167–78. Available from: http://www.sciencedirect.com/science/article/pii/S0268960X13000192
5. Landis-Piwowar K, Landis J, Keila P. The complete blood count and peripheral blood smear evaluation. In: Clinical laboratory hematology. 3rd ed. New Jersey: Pearson; 2015. p. 154-77.
6. Ford J. Red blood cell morphology. Int J Lab Hematol [Internet]. 2013 Mar 9 [cited 2018 Jul 12];35(3):351–7. Available from: https://doi.org/10.1111/ijlh.12082
7. Turgeon ML. Erythrocyte morphology and inclusions. In: Clinical hematology: theory and procedures. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1999. p. 99-111.