DiGuglielmo1 recognized that erythroid cell maturation was distinctly abnormal in certain neoplastic conditions of the bone marrow. In the most usual variety, referred to as erythroleukemia, an abnormal myeloblastic proliferation is combined with disordered megaloblastic erythroid maturation often leading terminally to typical acute myeloblastic leukemia. In other forms, the disorder may assume either a more chronic and nonprogressive course or a more rapid and fulminant course involving chiefly the red blood cell precursors.
Normal erythroid tissue is regulated by the hormone erythropoietin, which is produced in response to the need for an increased number of circulating red cells. The report to follow describes a patient with erythroleukemia who was investigated with the objective of determining whether "neoplastic" erythroid tissue behaves in an autonomous and unregulated fashion. By several parameters of measurement, erythropoiesis in this patient was found to respond to alterations in concentration of plasma erythropoietin.