Anisocytosis:
Chapter: 20a
Variation in red cell size. Normal red blood cells are 7 to 8 micrometers, and have an average volume of 90 fl, with a normal range of 80-100 fl. RBCs which are smaller than normal are termed microcytic (MCV 100). Macrocytic anemia has many causes, including folate/vitamin B12 deficiency and some drugs (e.g., methotrexate, Zidovudine (AZT), and hydroxyurea).