FRCPath Haematology Part 2: Morphology RBC Morphology Overview Microcytosis

Microcytosis – cells smaller than 7-7.2µm

Causes:

  • Thalassaemia
  • HbE/HbC
  • Congenital sideroblastic anaemia
  • Iron deficiency
  • MDS, particularly if associated with acquired HbH disease
  • Hyperthyroidism
  • Acquired sideroblastic anaemia
  • Heavy metal poisoning
Microcytosis. Peripheral blood film showing microcytosis
Peripheral blood film from a patient with iron deficiency anaemia showing microcytic, hypochromic RBCs. Note the normal lymphocyte nucleus size is larger than the surrounding RBCs.
Microcytosis. Peripheral blood film showing microcytosis
Peripheral blood film from a patient with ß thalassaemia trait showing microcytic, hypochromic RBCs. Note the normal lymphocyte nucleus size is larger than the surrounding RBCs.
Previous Topic
Back to Section
Next Topic