Dyserythropoiesis in iron-deficiency anemia: ultrastructural reassessment.

Iron deficiency is usually included among the causes of acquired dyserythropoiesis. This concept was derived mainly from light microscopic studies. To reassess such a notion at ultrastructural level, a transmission electron microscopic evaluation of bone marrow was performed in seven patients with iron-deficiency anemia. In contrast to the widely accepted concept, derived from light microscopic studies, only a small proportion (2-4%, not different from controls) of erythroblasts displayed some of the features of nuclear dyserythropoiesis. On the contrary, when examining the cytoplasm, we found a significantly increased number of void ropheocytotic vesicles in the majority of late erythroblasts as compared to controls (P less than 0.001). This feature may be considered as an ultrastructural marker of iron deficiency and is consistent with the present knowledge on transferrin-mediated delivery of iron to the cell.