Acanthocytes are red blood cells with irregular, spiky protrusions (spicules) on their surface. They can be differentiated from echinocytes as the protrusions on an echinocyte surface are regularly distributed and the usually the same size whereas this is not the case for acanthocytes. Some spicules in acanthocytes may be blunt rather than all being sharp or pointed. Acanthocytes cannot form rouleaux and are a non-reversible morphology of red cells.

There are many causes of acanthocytosis:

• Splenectomy
• Pyruvate kinase deficiency
• Degenerative neurological disease (neuroacanthocytosis)
• Liver disease (abetalipoprteinaemia)

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Image from personal photography.