RT Book, Section A1 Lichtman, Marshall A. A1 Kaushansky, Kenneth A1 Kipps, Thomas J. A1 Prchal, Josef T. A1 Levi, Marcel M. SR Print(0) ID 1126651116 T1 The Megaloblastic Anemias T2 Williams Manual of Hematology, 8e YR 2011 FD 2011 PB McGraw-Hill Education PP New York, NY SN 9780071622424 LK hemonc.mhmedical.com/content.aspx?aid=1126651116 RD 2024/03/28 AB Disorders caused by impaired synthesis of DNA.Prototype is pernicious anemia, a deficiency of vitamin B12 (cobalamin) caused by lack of intrinsic factor, required for its absorption.Characteristics are megaloblastic cells, typically present in the erythroid series as large cells with immature-appearing nuclei but with increasing hemoglobinization of the cytoplasm—often referred to as nuclear-cytoplasmic asynchrony.Megaloblastic granulocytic cells have large size, giant band neutrophils are a feature in the marrow and hypersegmented neutrophils in the marrow and blood. Megakaryocytes may be abnormally large with nuclear abnormalities.Other rapidly dividing tissue cells, such as intestinal epithelium and uterine cervical epithelium may also show cytologic abnormalities. A uterine cervical smear when megaloblastic cytopoiesis is present may be strikingly dysplastic.