Megaloblastic

This term indicates that bone marrow erythropoiesis has a specific morphological abnormality called megaloblastosis. For patients who are not on cytotoxic drugs, its presence usually indicates a deficiency of either vitamin B12 or folic acid. A bone marrow aspirate is not always necessary, as the presence of oval macrocytes and hypersegmented neutrophils on the blood film is strongly suggestive of its presence. A serum vitamin B12 and red cell folate estimation can then often make the diagnosis.