MedSchool: Ace Your OSCEsThe Medical Company
GET - On the App Store
Test Findings




  • Anisocytosis refers to increased variability of red blood cell size. Red cells are normally of uniform size, and significant variation
    • Look For

    • Elevated Red cell distribution width (RDW) on full blood count
    • Variability in red blood cell size on blood film
  • Anisocytosis may be caused by any condition that results in microcytosis or macrocytosis.
  • For example, a patient with early megaloblastic anaemia may have a mix of macrocytes and normally sized cells, resulting in an overall normal mean red cell volume (MCV) with anisocytosis.
    • Interpretation

    • More microcytic - suggests iron deficiency or sideroblastic anaemia
    • More normocytic - suggests early iron deficiency or megaloblastic anaemia, reticulocytosis (haemolysis, recovery following haemorrhage or bone suppression) or sickle cell anaemia
    • More macrocytic - suggests megaloblastic anaemia, myelodysplastic syndrome or chronic liver disease
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now