Anisopoikilocytosis Defination, Types, Morphology, Causes and more
Anisopoikilocytosis is a medical condition characterized by a variation in the size and shape of red blood cells. The underlying cause can be attributed to various anemias, most commonly beta thalassemia major, a form of microcytic anemia.
Anisopoikilocytosis occurs when red blood cells have different sizes and shapes.
Anisopoikilocytosis: A combination of two terms indicating abnormalities in both the size and shape of red blood cells
- Anisocytosis: Red blood cells of varying sizes on a blood smear.
- Poikilocytosis: Red blood cells of varying shapes on a blood smear
Blood smear results may also reveal mild anisopoikilocytosis. This means that the number of red blood cells with different sizes and shapes is more moderate.
Cells By Size:
Anisocytosis: Red blood cells of varying sizes on a blood smear.
| Cell Type and Approx size | Description |
|---|---|
| Microcytic (<6µm) | Red blood cells are smaller than a small lymphocyte. |
| Normocytic (6-8 µm) | Red blood cells are similar in size to a small lymphocyte. |
| Macrocytic (>8 µm) | Red blood cells are larger than a small lymphocyte. |
| Anisocytosis (variations) | Significant variation in the size of red blood cells. |
Cells By Sapte:
Poikilocytosis: Red blood cells of varying shapes on a blood smear
| Shape (Poikilocytosis) | Description |
|---|---|
| Normal | Typical biconcave disc-shaped red blood cells (discocytes). |
| Spiculated Cells | RBCs with spiky or irregular projections. |
| Acanthocyte (Spur Cell) | RBCs with irregular, thorny projections. Often associated with liver disease. |
| Echinocyte (Burr Cell) | RBCs with short, evenly spaced projections. Seen in uremia or dehydration. |
| Teardrop Cell (Dacrocyte) | RBCs shaped like a teardrop. Indicative of myelofibrosis or severe anemia. |
| Sickle Cell (Drepanocyte) | Crescent or sickle-shaped RBCs. Characteristic of sickle cell anemia. |
| Schistocyte | Fragmented RBCs resulting from mechanical damage. |
| Helmet Cell | A type of schistocyte resembling a helmet. Seen in hemolytic anemias. |
| Horn Cell (Keratocyte) | RBCs with horn-like projections. Found in microangiopathic hemolytic anemia. |
| Bite Cell | RBCs with a “bitten” appearance, due to removal of hemoglobin by macrophages. |
| Blister Cell | RBCs with a vacuole, appearing like a blister. |
| Ovalocyte | Oval or elongated RBCs. Seen in hereditary elliptocytosis or iron deficiency. |
| Spherocyte | Spherical RBCs without central pallor. Seen in hereditary spherocytosis. |
What are the causes Anisopoikilocytosis ?
Anisopoikilocytosis means both anisocytosis and poikilocytosis. Therefore, it is useful to start by looking at the causes of these two conditions individually.
Causes of Anisocytosis
The abnormal size of red blood cells seen in anisocytosis can be due to several different conditions:
- Anemias. These include iron deficiency anemia, hemolytic anemia, sickle cell anemia, and megaloblastic anemia.
- Hereditary spherocytosis. This is an inherited disease characterized by the presence of hemolytic anemia.
- Thalassemia. This is an inherited blood disorder characterized by decreased levels of hemoglobin and a decreased number of red blood cells in the body.
- Vitamin deficiency. Specifically, folate or vitamin B-12 deficiency.
- Cardiovascular disease. This can be acute or chronic.
Causes of Poikilocytosis
The causes of the abnormal red blood cell shape seen in poikilocytosis can also be due to a variety of conditions. Many of these conditions are the same as those that can cause anisocytosis:
- Anemias
- Hereditary Spherocytosis
- Hereditary Elliptocytosis, an Inherited Condition in Which Red Blood Cells Are Oval or Egg-shaped
- Thalassemia
- Folate and Vitamin B-12 Deficiency
- Liver Disease or Cirrhosis
- Kidney Disease
Causes of Anisopoikilocytosis:
There is some overlap between the conditions that cause anisocytosis and poikilocytosis. This means that anisopoikilocytosis can occur under the following conditions:
- Anemias
- Hereditary Spherocytosis
- Thalassemia
- Folate and Vitamin B-12 Deficiency
Read about RBC Morphology >>
