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BLOOD SMEARS is a topic covered in the Harrison's Manual of Medicine.

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  • Normal: 7.5 μm diameter. Roughly the size of the nucleus of a small lymphocyte.
  • Reticulocytes (Wright’s stain): large, grayish-blue, admixed with pink (polychromasia).
  • Anisocytosis: variation in RBC size; large cells imply delay in erythroid precursor DNA synthesis caused by folate or B12 deficiency or drug effect; small cells imply a defect in hemoglobin synthesis caused by iron deficiency or abnormal hemoglobin genes. The automated red cell distribution width (RDW) is a measure of anisocytosis.
  • Poikilocytosis: abnormal RBC shapes; the following are examples:
    1. Acanthocytes (spur cells): irregularly spiculated; abetalipoproteinemia, severe liver disease, rarely anorexia nervosa.
    2. Echinocytes (burr cells): regularly shaped, uniformly distributed spiny projections; uremia, RBC volume loss.
    3. Elliptocytes: elliptical; hereditary elliptocytosis.
    4. Schistocytes (schizocytes): fragmented cells of varying sizes and shapes; microangiopathic or macroangiopathic hemolytic anemia.
    5. Sickled cells: elongated, crescentic; sickle cell anemias.
    6. Spherocytes: small hyperchromic cells lacking normal central pallor; hereditary spherocytosis, extravascular hemolysis as in autoimmune hemolytic anemia, G6PD deficiency.
    7. Target cells: central and outer rim staining with intervening ring of pallor; liver disease, thalassemia, hemoglobin C, and sickle C diseases.
    8. Teardrop cells: myelofibrosis, other infiltrative processes of marrow (e.g., carcinoma).
    9. Rouleaux formation: alignment of RBCs in stacks; may be artifactual or due to paraproteinemia (e.g., multiple myeloma, macroglobulinemia).

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Loscalzo, Joseph, et al., editors. "BLOOD SMEARS." Harrison's Manual of Medicine, 19th ed., McGraw Hill Inc., 2017. harrisons.unboundmedicine.com/harrisons/view/Harrisons-Manual-of-Medicine/623583/all/BLOOD_SMEARS.
BLOOD SMEARS. In: Loscalzo J, Jameson JL, Longo DL, et al, eds. Harrison's Manual of Medicine. 19th ed. McGraw Hill Inc.; 2017. https://harrisons.unboundmedicine.com/harrisons/view/Harrisons-Manual-of-Medicine/623583/all/BLOOD_SMEARS. Accessed April 18, 2019.
BLOOD SMEARS. (2017). In Loscalzo, J., Jameson, J. L., Longo, D. L., Hauser, S. L., Fauci, A. S., & Kasper, D. L. (Eds.), Harrison's Manual of Medicine. Available from https://harrisons.unboundmedicine.com/harrisons/view/Harrisons-Manual-of-Medicine/623583/all/BLOOD_SMEARS
BLOOD SMEARS [Internet]. In: Loscalzo J, Jameson JL, Longo DL, Hauser SL, Fauci AS, Kasper DL, editors. Harrison's Manual of Medicine. McGraw Hill Inc.; 2017. [cited 2019 April 18]. Available from: https://harrisons.unboundmedicine.com/harrisons/view/Harrisons-Manual-of-Medicine/623583/all/BLOOD_SMEARS.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - BLOOD SMEARS ID - 623583 ED - Loscalzo,Joseph, ED - Jameson,J Larry, ED - Longo,Dan L, ED - Hauser,Stephen L, ED - Fauci,Anthony S, ED - Kasper,Dennis L, BT - Harrison's Manual of Medicine UR - https://harrisons.unboundmedicine.com/harrisons/view/Harrisons-Manual-of-Medicine/623583/all/BLOOD_SMEARS PB - McGraw Hill Inc. ET - 19 DB - Harrison's Manual of Medicine DP - Unbound Medicine ER -