From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Other namesMacrocytes, megalocytes

Macrocytosis is the enlargement of red blood cells with near-constant hemoglobin concentration, and is defined by a mean corpuscular volume (MCV) of greater than 100 femtolitres (the precise criterion varies between laboratories). The enlarged erythrocytes are called macrocytes or megalocytes (both words have roots meaning "big cell"). As a symptom its cause may be relatively benign and need no treatment or it may indicate a serious underlying illness.


In humans, most commonly (especially when the increase in size is mild, and just above normal range) the cause is bone marrow dysplasia secondary to alcohol use disorder.

Poor absorption of vitamin B12 in the digestive tract can also cause macrocytosis.

Gastrointestinal diseases that may cause macrocytosis include celiac disease (severe sensitivity to gluten from wheat and other grains that causes intestinal damage) and Crohn's disease (inflammatory bowel disease that can affect any part of the gastrointestinal tract).

Other causes may include:


No complications arise from macrocytosis itself and a prognosis will be determined from its cause.

See also[edit]


  1. ^ Yadav, Manish K.; Manoli, Nandini M.; Madhunapantula, SubbaRao V. (25 October 2016). "Comparative Assessment of Vitamin-B12, Folic Acid and Homocysteine Levels in Relation to p53 Expression in Megaloblastic Anemia". PLOS ONE. 11 (10): e0164559. Bibcode:2016PLoSO..1164559Y. doi:10.1371/journal.pone.0164559. PMC 5079580. PMID 27780269.
  2. ^ Fessler, Michael B.; Rose, Kathryn; Zhang, Yanmei; Jaramillo, Renee; Zeldin, Darryl C. (November 2013). "Relationship between serum cholesterol and indices of erythrocytes and platelets in the US population". Journal of Lipid Research. 54 (11): 3177–3188. doi:10.1194/jlr.P037614. PMC 3793622. PMID 23999863.
  3. ^ Greenberg, Peter L.; Attar, Eyal; Bennett, John M.; Bloomfield, Clara D.; Borate, Uma; De Castro, Carlos M.; Deeg, H. Joachim; Frankfurt, Olga; Gaensler, Karin; Garcia-Manero, Guillermo; Gore, Steven D.; Head, David; Komrokji, Rami; Maness, Lori J.; Millenson, Michael; O’Donnell, Margaret R.; Shami, Paul J.; Stein, Brady L.; Stone, Richard M.; Thompson, James E.; Westervelt, Peter; Wheeler, Benton; Shead, Dorothy A.; Naganuma, Maoko (July 2013). "Myelodysplastic Syndromes". Journal of the National Comprehensive Cancer Network. 11 (7): 838–874. doi:10.6004/jnccn.2013.0104. PMC 4000017. PMID 23847220.

External links[edit]