In the case to be described, enormous numbers of nucleated erythrocytes were present in the circulating blood and bone marrow initially and not only persisted unaffected by treatment but progressively increased in numbers. An associated proliferation of the immature cells characteristic of leukemia was absent. So far as could be ascertained, this blood dyscrasia was not initiated by or associated with hemolysis and was not related to erythroblastosis fetalis, Mediterranean anemia (hereditary leptocytosis) or sickle cell anemia. Such a condition may be designated as an erythremia or, possibly, more aptly as an erythroblastemia.
The continued presence of nucleated erythrocytes in large numbers in the circulating blood has not been reported frequently. In infants and children nucleated red blood cells sometimes have been observed in hemolytic anemias, hemophilia, hemorrhagic disease of the newborn, hereditary leptocytosis and leukemia. Children are occasionally seen in whom erythroblasts transiently form the majority of nucleated cells