An anomaly of erythroid lineage cells, that is, of the erythropoietic cells in the lineage leading to and including erythrocytes.
Comment:
Proerythroblasts are the earliest recognizable erythroid precursors. They are followined during the process of hematopoiesis by basophilic erythroblasts, polychromatic (polychromatophilic) erythroblasts, orthochromatic erythroblasts (normoblasts), reticulocytes, and finally mature erythrocytes (red blood cells). This term encompasses structural anomalies of erythroblast precursors in the bone marrow.