Macrocytic anemia is seen in all EXCEPT
High-Yield Explanation
Anemia of chronic disease REF: Wintrobe's hematology 11th ed p. 77 Morphologic and biochemical criteria allow macrocytic anemias to be divided into two groups: the megaloblastic anemias and the nonmegaloblastic macrocytic anemias. Pathogenetic Classification of Megaloblastic Anemia Nonmegaloblastic Macrocytic Anemias Vitamin B 12 deficiency Dietary deficiency (rare) Lack of intrinsic factor Pernicious anemia Gastric surgery Ingestion of caustic materials Functionally abnormal intrinsic factor Biologic competition for vitamin B 12 Small-bowel bacterial overgrowth Fish tapeworm disease Familial selective vitamin B 12 malabsorption (Imerslund-Grasbeck syndrome) Drug-induced vitamin B 12 malabsorption Chronic pancreatic disease Zollinger-Ellison syndrome Diseases of the ileum Previous ileum resection Regional enteritis Folate deficiency Dietary deficiency Increased requirements Pregnancy Infancy Chronic hemolytic anemia Alcoholism Congenital folate malabsorption Drug-induced folate deficiency Extensive intestinal resection, jejunal resection Combined folate and vitamin B 12 deficiency Tropical sprue Gluten-sensitive enteropathy Inherited disorders of DNA synthesis Orotic aciduria Lesch-Nyhan syndrome Thiamine responsive megaloblastic anemia Methyl-tetrahydrofolate reductase Formiminotransferase Dihydrofolate reductase Transcobalamin II deficiency Homocystinuria and methylmalonic aciduria Drug- and toxin-induced disorders of DNA synthesis Folate antagonists (e.g., methotrexate) Purine antagonists (e.g., 6-rnercaptopurine) Pyrimidine antagonists (e.g., cytosine arabinoside) Alkylating agents (e.g., cyclophosphamide) Zidovudine (AZT, Retrovir) Trimethoprim Oral contraceptives Nitrous oxide Arsenic Chlordane Erythroleukemia Associated with accelerated erythropoiesis Hemolytic anemia Post hemorrhagic anemia Alcoholism Liver disease Myelodysplastic syndrome Myelophthisic anemias Aplastic anemia Acquired sideroblastic anemia Hereditary dyserythropoietic anemia (congenital dyserythropoietic anemia types I and III) Diamond-Blackfan anemia Hypothyroidism