Anisocytosis Defination, Types, Causes, Symptoms and more
Anisocytosis is characterized by the presence of red blood cells of different sizes. Normal red blood cells are usually the same size. Red blood cells of different sizes can be a sign of anemia, a condition that can cause symptoms such as fatigue and shortness of breath. Treatment depends on the cause of anisocytosis.
Anisocytosis describes red blood cells that vary in size. Sometimes, a change in red blood cell size can indicate an underlying medical problem. You may learn that your red blood cells are different sizes when you receive the results of a blood test.
- Aniso: unequal or uneven.
- Cytosis: relating to cells (in this case, red blood cells in particular).
Anisocytosis is a medical condition in which the sizes of different red blood cells/erythrocytes are unequal.
- Anisocytosis refers to excessive variation in red blood cell size which can be quantitatively determined by interpreting peripheral blood smears and automatically assessing red blood cell size distribution.
- Red blood cell distribution width (RDW) represents a quantitative measure of anisocytosis.
- RDW is a measure of red blood cell volume variability and is routinely performed by automated cell counters as part of red blood cell counting.
- It is calculated as a coefficient of variation of red blood cell volume distribution divided by mean corpuscular volume (MCV).
- Anisocytosis is not a condition in itself, but is associated with another condition, such as iron deficiency anemia and/or other blood disorders.
Types of Anisocytosis:
If anisocytosis occurs, your red blood cells may be smaller or larger than normal red blood cells.
- Microcytosis (>6μm) means you have smaller red blood cells than normal.
- Normocytosis (6-8μm) means your Red blood cells are similar in size to a small lymphocyte.
- Macrocytosis (>8μm) means your red blood cells are larger than normal.
You may also have a mixture of larger and smaller red blood cells.
| Cell Type and Size | Description |
|---|---|
| Microcytic (>6μm) | Red blood cells are smaller than a small lymphocyte. |
| Normocytic (6-8μm) | Red blood cells are similar in size to a small lymphocyte. |
| Macrocytic (>8μm) | Red blood cells are larger than a small lymphocyte. |
| Anisocytosis (Name of Size Variations) | Significant variation in the size of red blood cells. |
Symptoms of Anisocytosis:
The most common symptoms are the same as those of anemia. You may feel:
- Weakness or fatigue.
- Shortness of breath (dyspnea).
- Fast or irregular heartbeat (arrhythmia).
- Occasional ringing in the ear (pulsatile tinnitus).
- Headaches.
- Dizziness.
- Pale skin.
- Chest pain.
Cuses of Anisocytosis :
- Iron Deficiency Anaemia, Especially if Mixed With Folate Deficiency
- Thalassaemia
- Megaloblastic Anaemia
- Sideroblastic Anaemia
- Blood Transfusion – the Host and Infused Blood Cells Having Different Sizes
Diagnosis of Anisocytosis:
The diagnosis of anisocytosis can be made in several ways, of which the blood smear is the most common procedure.
- Blood Smear:
- A blood sample is taken and a thin layer of blood is spread on a sterile glass slide.
- The slide is then stained, dried, and viewed under a microscope at appropriate magnification.
- The staining allows the different types as well as the size of the cells to be differentiated.
- The smear is used to observe and record the size and shape, as well as the number of red blood cells, the amount of hemoglobin in each red blood cell, the cell volume, and the concentration of hemoglobin in each red blood cell.
Other procedures that may be used in the diagnosis of anisocytosis include:
Mangement and Treatment:
How is Anisocytosis treated?
Treatment depends on the cause of the change in red blood cell size. Treatments may include:
- Treatment for anisocytosis depends on its cause.
- Vitamin B12 and Folate Supplements, if the cause is a nutritional deficiency.
- A Blood Transfusion, for certain inherited diseases, such as sickle cell anemia.
- A Bone Marrow Transplant, if you have trouble making red blood cells. Your body’s red blood cells are made in the bone marrow. You may need this treatment if myelodysplastic syndromes or certain forms of cancer are causing the anisocytosis.
Read about RBC Morphology >>
