Acanthocytes are red blood cells that show many spicules when viewed on a wet film.

• acanthocytosis refers to the transformation of the normal biconcave disc erythrocyte into one with a few irregularly shaped external projections distributed unevenly at its membrane surface
• associated with a variety of inherited and acquired disorders
  • acanthocytes were first observed in abetalipoproteinemia more than 50 years ago
  • since the first association the occurrence of acanthocytes has been reported in several other hereditary and acquired disorders including
    • chorea-acanthocytosis
    • McLeod phenotype
    • hereditary spherocytosis with a beta-spectrin deficiency
    • alcoholic cirrhosis
    • uraemia
    • vitamin E deficiency
    • anorexia nervosa
    • hypothyroidism
  • an acanthocyte differs morphologically from the echinocyte, readily induced by contact with glass, which has 10-40 regularly shaped external projections distributed evenly at the membrane surface
    • the acanthocyte is characterized by the presence of a few irregularly shaped external projections distributed unevenly at the membrane surface

Reference:

• (1) L.D. Walensky, N. Mohandas and I.V. Lux SE, Disorders of the red cell membrane. In: R.H. Handin, I.V. Lux SE and T.P. Stossel, Editors, Blood: principles and practice in hematology (2nd Edition ed.), Lippincott Williams & Wilkins, Philadelphia (2003):1709-1858.