Macrocytosis (ICD-10-GM D75.8: Other specified diseases of the blood and blood-forming organs, ICD-10-GM R 71: Alteration of erythrocytes) refers to the occurrence of abnormally large erythrocytes (red blood cells), so-called macrocytes, whose mean corpuscular volume (MCV) is increased to more than 98 (100) femtoliters (fl) compared with normal.
MCV can be calculated from the hematocrit (volume fraction of cellular elements in the blood) and the number of erythrocytes in the blood using the following formula: MCV = hematocrit / erythrocyte countComputationally, MCV is related to two other parameters: MCV = MCH* / MCHC* * .* MCH (mean corpuscular hemoglobin)* * MCHC (mean corpuscular hemoglobin concentration).
If anemia (anemia), i.e. a reduced hemoglobin concentration (concentration of the blood pigment), is present at the same time, it is referred to as macrocytic anemia.
Anemias are differentiated by red cell volume (MCV) as follows:
- <80: microcytic anemia.
- 80-100: normocytic anemia
- > 100: macrocytic anemia
Macrocytosis without pathological significance is found in neonates and infants and occasionally in pregnant women, among others.
Macrocytosis can be a symptom of many diseases (see under “Differential diagnoses”).
The prevalence (disease incidence) for macrocytosis is approximately 3% in the general population.
Course and prognosis: Course and prognosis depend on the cause of the disease.