Skip to Content


Pronunciation: e-rith'ro-blast

Definition: Originally, a term denoting all forms of human red blood cells containing a nucleus, both pathologic (megaloblastic) and normal (normoblastic). The pathologic or megaloblastic series is observed in pernicious anemia in relapse. The term megaloblast is also used to indicate the first generation of cells in the red blood cell series that can be distinguished morphologically; hence, with this usage, megaloblast denotes both a normal and an abnormal cell. In the erythroblastic series of maturation four stages of development can be recognized: 1) proerythroblast, 2) basophilic erythroblast, 3) polychromatic erythroblast, and 4) orthochromatic erythroblast. In the megaloblastic series of maturation, stages similar to those found in the normoblastic series are seen: 1) promegaloblast, 2) basophilic megaloblast, 3) polychromatic megaloblast, and 4) orthochromatic megaloblast. In the normal series of maturation, after loss of the nucleus, young erythrocytes are called reticulocytes; these cells may be recognized with supravital stains such as brilliant cresyl blue; ultimately the reticulocytes become erythrocytes, or mature red blood cells.

Synonym(s): erythrocytoblast

[erythro- + G. blastos, germ]

Disclaimer: This site is designed to offer information for general educational purposes only. The health information furnished on this site and the interactive responses are not intended to be professional advice and are not intended to replace personal consultation with a qualified physician, pharmacist, or other healthcare professional. You must always seek the advice of a professional for questions related to a disease, disease symptoms, and appropriate therapeutic treatments.
© Copyright 2017 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.