Summary of Abnormal Red Blood Cell Morphologies and Disease States

• Before we start with the abnormal morphologies, let’s talk about normal morphology of Red Blood Cells.
• Normal mature RBC are biconcave, round discs that are about 6 – 8 in diameter, which is only slightly smaller than the normal small mature lymphocytes ( about 6 – 10 in diameter).
• The term used to indicate red blood cells of normal size and shape is normocytic. The term used to indicate a normal color or central pallor (i.e., normal hemoglobin content) is normochromic

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Hypochromic: Erythrocytes that demonstrate a central pale area that becomes larger and paler as the hemoglobin content diminishes.

• Iron Deficiency
• Sideroblastic Anaemia
• Thalassaemia

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Anisochromic: indicates the presence of both normochromic and Hypochromic

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Polychromasia: Changeable terms used to indicate the increased presence of non-nucleated immature erythrocytes (Polychromatophilic erythrocytes) that contain residual RNA which gives a blue-gray tint to the red cells. These cells, which remain after ejection of the nucleus from the orthochromatic erythroblast are slightly larger than mature erythrocytes. After exposure to a supravital stain, the cytoplasm organelles of these cells clump into an easily recognized blue-staining reticulum and the cells is called a reticulocytes.

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Anisocytosis:  is a “generic” term used to indicate variation in shape of erythrocytes (e.g. oval, pear-shaped, teardrop-shaped, saddle-shaped, helmet-shaped, sickle-shaped, and irregularly shaped).

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Microcytosis: abnormally small erythrocytes (i.e., less than 6 in diameter). compare with the size for small lymphocyte.

• Found with Hypochromic

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Macrocytosis: abnormally large erythrocytes (i.e., less than 8 in diameter).

• Megaloblastic Anaemia
• High reticulocytes count
• Liver disease
• Myelodysplastic syndrome

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Target Cells (Codocytes): erythrocytes that are thinner than normal which show a peripheral rim of hemoglobin with a dark central hemoglobin-containing area. A pale unstained ring containing less hemoglobin separates the central and peripheral zones and gives the cell a target appearance.

• Liver Disease
• Hemoglobinopathies
• Thalassaemia
• Sideroblastic anemia

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Spherocytes: are nearly spherical erythrocytes which are nearly spherical erythrocytes which usually have a diameter smaller than normal. They lack the central pale area due to their spherical shape.

• Hemolytic anemia
• Post transfusion
• Hereditary sphercocytosis

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Tear-Drop Cells:

• Severe Anaemia
• Myloproliferative disorders

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Elliptocytes and Ovalocytes: are interchangeable terms used to indicate ovalshaped erythrocytes.

• Hereditary elliptocytosis
• Iron-deficiency anaemia
• Thalassaemia

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Stomatocytes:

• Acute alcoholism
• Malignancies

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Helmet Cells:

• G6PD deficiency
• Pulmonary emboli

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Schistocytes: are fragmented red cell segments that are the result of some hemolytic process. These segments can be a variety of shapes but helmet cells and triangularly-shaped cells are particularly characteristic.

• Disseminated intra-vascular coagulopathy (DIC)
• Thrombotic Thrombocytopenia purpura (TTP)
• Hemolytic uremic syndrome (HUS)

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Sickle cells (drepanocyes): are interchangeable terms used to indicate sickle-like forms of erythrocytes (crescent-shaped, irregular spines, filaments, holly-leaf appearance) noted when RBC containing HbS are subjected to reduction in oxygen tension or pH.

• Sickle cell anaemia
• Sickle thalassaemia

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Acanthocytes (Spur Cell):

• Congenital abetalipoproteinemia
• Vitamin E deficiency
• Alcohol intoxication
• Post-splenectomy

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Burr Cells:

• Liver disease
• Renal disease
• Severe burns
• Bleeding gastric ulcers
• Maybe artifact

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Howell-Jelly: are intracellular particles which are smooth, round remnants of nuclear chromatin (DNA. Usually, only one per cell is seen but, occasionally, there may be more than one

• Megaloblastic anaemia
• Mylodysplastic

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Heinz Bodies

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Cabot Rings

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Basophilic Stippling: is the term used to indicate the presence of irregular basophilic granules in the cytoplasm of erythrocytes. The granules are composed of unstable RNA and may be fine of coarse.

• Lead Poisoning
• Thalassaemia
• Significant anaemia
• Dyserythropoiesis

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Hemoglobin C crystals:  are hexagonal crystals that may be found in individuals with HbC syndromes. The crystals may intracellular or extra-cellular.

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Pappenheimer Bodies:  are intracellular inorganic iron-containing granules that may be ob-served on Wright’s stained peripheral blood smears.

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Rouleaux formation: describes an aggregation of erythrocytes that are aligned one upon the other, resembling stacks of coins

• High level of circulating acute-phase proteins.
• with High ESR rate.
• autoimmune conditions
• myeloma

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Agglutination of red cells:  is caused by agglutinins and resembles Rouleaux but is more irregular with round clumps rather than linear Rouleaux

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