Iron Deficiency

Blood film features:

• Anisopoikilocytosis
• Microcytic, hypochromic
• Elliptocytes, particularly very narrow elliptocytes – “pencil cells”
• Pre-keratocytes and keratocytes
• Some target cells (less than beta thal trait)
• Occasional teardrops
• May have reactive thrombocytosis

This blood film is from a patient with polycythaemia vera. The patient also has a concomitant iron deficiency, as evidenced by the microcytosis, numerous elliptocytes and occasional keratocytes.

Differential diagnosis:

• Thalassaemia trait (prominent target cells and basophilic stippling, high RBC count with hypochromic RBCs)
• Anaemia of chronic disease (rouleux, reactive leukocytosis)
• Polycythaemia with iron deficiency (high RBC count with hypochromic RBCs, may have leukocytosis or thrombocytosis with platelet anisocytosis)

Other resources:

• ASH image bank: iron deficiency