A Case of juvenile chronic myelocytic leukemia who developed an erythroblastic phase is presented. The erythroblastic phase was characterized by anemia, bone marrow erythroid hyperplasia and the appearance of nucleated red blood cells in the peripheral blood. At the erythroblastic phase transfusion resulted in a suppression of erythropoiesis in the peripheral blood and bone marrow. The in vitro methylcellulose culture studies indicated that the CFU-E in the bone marrow of this patient was dependent upon erythropoietin for the differentiation and proliferation. The erythroid progenitor was not cloned in the absence of erythropotin.
These findings suggested that the proliferation and differentiation of erythroid stem cells remain dependent upon phisiologic regulation during erythroblastic phase of juvenile chronic myelocytic leukemia.