The significance of erythroblastemia must be considered in the context of the clinical setting in which it is found. Interpretation should take into account the number and spectrum of maturity of the nucleated red cells; the presence or absence of reticulocytosis and other red cell abnormalities (for example, poikilocytosis); the presence or absence of anemia; the presence or absence of circulating immature granulocytes or bizarre platelets and the presence or absence of the spleen. Circulating nucleated red cells indicate intravascular hemopoiesis or disruption of marrow structure or the inability of the bone marrow's screen mechanism to prevent their passage into circulation. In the latter situations, it usually indicates an unfavorable prognosis.