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

Normocytic and Normochromic RBC

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

Iron Deficiency

Sideroblastic Anaemia

Thalassaemia

Hypochromic RBC

Anisochromic: indicates the presence of both normochromic and Hypochromic
Anisochromic (Normochromic plus Hypochromic)

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.

Polychromasia

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).

Anisocytosis

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

Found with Hypochromic

Microcytosis

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

Megaloblastic Anaemia
High reticulocytes count
Liver disease
Myelodysplastic syndrome

Macrocytosis

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

Target Cells

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
Spherocytes

Tear-Drop Cells:

Severe Anaemia
Myloproliferative disorders

Teardrop cells (dacrocytes)

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

Hereditary elliptocytosis
Iron-deficiency anaemia
Thalassaemia

Elliptocytes

Stomatocytes:

Acute alcoholism
Malignancies
Stomatocytes

Helmet Cells:

G6PD deficiency
Pulmonary emboli

Helmet Cells (Keratocytes)

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)

Schistocytes

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

Sickle Cells

Acanthocytes (Spur Cell):

Congenital abetalipoproteinemia
Vitamin E deficiency
Alcohol intoxication
Post-splenectomy

Acanthocytes

Burr Cells:

Liver disease
Renal disease
Severe burns
Bleeding gastric ulcers
Maybe artifact
Acanthocyte vs Echinocyte

Echinocyte (Burr Cell)

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

Howell-Jolly Bodies

Heinz Bodies

Heinz Bodies

Cabot Rings

Cabot Rings

A – Cabot ring
B – Howell-Jolly body

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

Basophilic Stippling

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