- The occurrence of unusually large numbers of macrocytes in the circulating blood. SYN: macrocytosis, megalocythemia, megalocytosis. [macrocyte + G. haima, blood]- hyperchromatic m. an inexact term frequently used for macrocytes that contain an unusually large amount of hemoglobin, but are actually normochromic; although the total mass of hemoglobin is greater than normal (owing to the large cells), the percentage of hemoglobin in the cells is not greater than normal.
* * *mac·ro·cy·the·mia (mak″ro-si-theґme-ə) [macrocyte + hem- + -ia] a condition in which the erythrocytes are larger than normal, such as in macrocytic anemia and some types of liver disease. Called also macrocytosis and megalocytosis.
Medical dictionary. 2011.