Macrocytic anemia UMLS:C0002886 Macrocytic anaemia The causes of macrocytosis can be broadly classified as megaloblastic and nonmegaloblastic. Megaloblastic processes are characterized on the peripheral smear by macroovalocytes and hypersegmented neutrophils, which are absent in nonmegaloblastic macrocytic processes. Nonmegaloblastic processes have round macrocytes or macroreticulocytes. SNOMEDCT_US:83414005 HP:0001972 A type of anemia characterized by increased size of erythrocytes with increased mean corpuscular volume (MCV) and increased mean corpuscular hemoglobin (MCH). Anemia of inadequate production