Desacetyl vinblastine amide sulfate induced ineffective erythropoiesis.

Ineffective erythropoiesis occurred during desacetyl vinblastine amide sulfate (VDS) therapy of a patient with metastatic Ewing's sarcoma. The peripheral blood was characterized by anisocytosis, poikilocytosis and reticulocytopenia. Bone marrow showed megaloblastic red cell hyperplasia with nuclear fragmentation, binuclearity and abnormal metaphases. Radioiron incorporation into red cells was markedly decreased. Electron microscopy showed red cell surface changes previously called ropalocytosis. Normal erythropoiesis promptly resumed when VDS treatment was withheld. Although less common than leukopenia, red cell abnormalities are part of the spectrum of vinca alkaloid toxicity.