- The term macrocytosis describes the presence of macrocytes on a blood film, together with a raised mean corpuscular volume (MCV). It is a common finding in the results of an FBC and may or may not be associated with an anaemia.
- Macrocytosis may occur as a laboratory artefact, perhaps following incorrect storage of the sample. A spuriously raised MCV may also occur due to cold agglutinins, paraproteins as in myeloma, hyperglycaemia or marked leukocytosis. Macrocytic anaemia describes a macrocytosis associated with a reduced haemoglobin and most commonly occurs as a result of a megaloblastic anaemia.
- Macrocytic anaemia can be classified as megaloblastic and non-megaloblastic. Megaloblastic refers to a characteristic abnormality of the erythroblasts in the bone marrow in which the maturation of the nucleus is delayed relative to the cytoplasm. It results from defective DNA synthesis. It affects the 3 components of the marrow which result in hypersegmented wbcs , macrocytes and large plts.
Macrocytic Anemia Interpretation Diagram
Megaloblastic and non-megaloblastic Anemia Interpretation Diagram
