Kaferle Joyce, Strzoda Cheryl E
Department of Family Medicine, University of Michigan, Ann Arbor, Michigan, USA.
Am Fam Physician. 2009 Feb 1;79(3):203-8.
Macrocytosis, generally defined as a mean corpuscular volume greater than 100 fL, is frequently encountered when a complete blood count is performed. The most common etiologies are alcoholism, vitamin B12 and folate deficiencies, and medications. History and physical examination, vitamin B12 level, reticulocyte count, and a peripheral smear are helpful in delineating the underlying cause of macrocytosis. When the peripheral smear indicates megaloblastic anemia (demonstrated by macro-ovalocytes and hyper-segmented neutrophils), vitamin B12 or folate deficiency is the most likely cause. When the peripheral smear is non-megaloblastic, the reticulocyte count helps differentiate between drug or alcohol toxicity and hemolysis or hemorrhage. Of other possible etiologies, hypothyroidism, liver disease, and primary bone marrow dysplasias (including myelodysplasia and myeloproliferative disorders) are some of the more common causes.
大细胞性贫血通常定义为平均红细胞体积大于100飞升，在进行全血细胞计数时经常会遇到。最常见的病因是酗酒、维生素B12和叶酸缺乏以及药物。病史和体格检查、维生素B12水平、网织红细胞计数以及外周血涂片有助于明确大细胞性贫血的潜在病因。当外周血涂片显示巨幼细胞贫血（由大卵圆形红细胞和多分叶中性粒细胞证实）时，维生素B12或叶酸缺乏是最可能的原因。当外周血涂片不是巨幼细胞性的时，网织红细胞计数有助于区分药物或酒精毒性与溶血或出血。在其他可能的病因中，甲状腺功能减退、肝脏疾病和原发性骨髓发育异常（包括骨髓增生异常和骨髓增殖性疾病）是一些较常见的原因。
