Stomatocytes (RBCs with slit-like central pallor)

Stomatocytosis is a rare condition of RBCs in which a mouthlike or slitlike pattern replaces the normal central zone of pallor. These cells are associated with congenital and acquired hemolytic anemia. The symptoms result from the anemia.

Stomatocytes are erythrocytes with a central slit or stoma instead of a circular area of pallor when examined on dried smears; they are uniconcave rather than biconcave, giving them a bowl-like appearance. A few stomatocytes may be observed in blood smears prepared from normal individuals, as well as from patients with acute alcoholism and hepatobiliary disease. Large numbers of stomatocytes are associated with very rare hereditary disorders of red cell cation permeability leading to increased or decreased red cell water content.

Hereditary Stomatocytosis comprises two different diseases: the xerocytosis or dehydrated hereditary stomatocytosis and the overhydrated hereditary stomatocytosis. Both are genetic disorders mainly due to an abnormality of red cell membrane permeability to monovalent cations (Na+ and K+) resulting in an alteration in the red blood cell water content. The movement of divalent cations and anions is normal. Typical red blood cells are known as stomatocytes (mouth featured cells) appear in blood smear examination. The clinical manifestation can vary from asymptomatic to severe hemolytic anemia. Hereditary Stomatocytosis shows autosomal dominant inheritance and may cause severe hemolytic anemia presenting very early in life.

Hemolytic anemia with stomatocytosis (up to 40–60%), elevated reticulocyte count, elevated serum bilirubin levels, and reduced serum haptoglobin concentration in children or adolescents are characteristic features of hereditary stomatocytosis.



Stomatocytes have been noted in diverse acquired conditions, including neoplasms, cardiovascular and chronic liver disease, alcoholism, and therapy with drugs, some of which are known to be stomatocytogenic in vitro. In some of these conditions, the percentage of stomatocytes on the peripheral blood smear can approach 100%. However, the clinical significance of this observation is unclear because stomatocytes are absent in most patients with the conditions listed. Furthermore, some stomatocytes can be found in normal individuals (3–5%). The most consistent association is that of stomatocytosis and heavy alcohol consumption.

Splenectomy ameliorates anemia in some cases.

Acquired stomatocytosis with hemolytic anemia occurs primarily with recent excessive alcohol ingestion. Stomatocytes in the peripheral blood and hemolysis disappear within 2 weeks of alcohol withdrawal. Stomatocytosis could also be seen in thalassemia, neoplastic, cardiovascular or hepatobiliary disease including acute alcoholism and during therapy with certain drugs some of which are known to be stomatocytogenic in vitro.


Patrick G. Gallagher; Faramarz Naeim; and Bertil Glader. Red Blood Cell Membrane Disorders.

Article Name
Stomatocytosis is a rare condition of RBCs in which a mouthlike or slitlike pattern replaces the normal central zone of pallor.
Publisher Name
Publisher Logo


  • Patricia Hanley

    How do they test for for Stomatocytosis? My 25 year old daughter has a chronic illness Endometriosis stage 4( which has not got the amount of research it should) and she has symptoms of Anemia.. Her hematocrit is 32.5 and hemoglobin is 10.5 and her latest blood test says Stomatocytes are present but no percentage. Most doctors want to blame everything on her Endometriosis but anemia is not a symptom. So we just want to make sure we arent missing anything. Thank you for any information or advice.

    • Hi Patricia,
      Stomatocytes are identified on the blood smear and can be seen in a variety of medical conditions especially liver disease and excess alcohol consumption. I don’t think there is a direct link between endometriosis and stomatocytosis. Anemia associated with endometriosis could be secondary to iron deficiency caused by heavy periods.

  • Michele Carter

    I have had various blood tests and a blood smear test said occasional target cells. Image result for Stomatocytes
    Stomatocytes and elliptocytes present. Can you cause this to happen if you work too much, dont sleep enough, or are stressed or dont eat properly, why is my blood test showing this please and what does it mean for me? can it go and turn to a normal blood test again. I dont drink or smoke. Thank you. Michele

    • Hi Michele,
      Thank you for your comment.
      Some stomatocytes and elliptocytes can be seen in normal individuals and they don’t have any clinical significance as long as you are not anemic or having chronic liver disease. You can simply ignore them.

  • soft dev

    Can i ask what is the possible treatment for the acquired stomatocytes.

    • Hi,
      Thanks for your comment.
      The treatment of the acquired stomatocytosis is the treatment of the underlying cause, e.g. liver disease, excessive alcohol ingestion, etc.

  • Louie Reyes

    I have had various blood test, and it said i have Silent congenital ovalocytosis and stomatocytosis and reactive leucocytosis.
    What is the possible treatment and can it go and turn to a normal blood test again.

    • Hi Louie,
      Thanks for your comment.
      At present, there is no specific treatment for Hereditary Stomatocytosis. Many patients with hemolytic anemia take folic acid (vitamin B9) since the greater turnover of cells consumes this vitamin. During crises, transfusion may be required. Unlike hereditary spherocytosis, splenectomy is not indicated.

  • MW

    I know very little about a childhood blood disorder that may be hereditary stomatocytosis. I recall being told that I could be found eating dirt as a toddler and that I was transfused in the early 1970s. Throughout life (now 53, male), I have either been anemic or on the low end of the normal range and had low iron level readings in blood tests. A year ago, I had iron infusions and took an iron supplement. Energy level and blood test greatly improved. I discontinued the supplement when my iron level was in the upper end of the range (about 9 months ago). Endoscopy was unremarkable. One benign polyp on colonoscopy. No alcohol for three years. Had been a drinker (at times heavy) for 30 years. Stomatocytosis observed by hematologist over last several years. Iron levels falling since discontinuation of supplements. Feeling fatigue and chest tightness that improves with exercise. I have asthma, but I actually breath better the more I exercise. Sleep apnea well controlled with biPAP. I walk 20+ miles a week. Also have Selective IgM deficiency, which makes me very prone to respiratory infections. I live in a humid environment, and lately feel like I just can’t breath. Makes me anxious. Seeing the hematologist for tests again soon. Suspect I have anemia and low iron. No obvious bleeding. Slightly fatty liver, but not awful. Enzymes in normal range. A1C slightly elevated but not diabetic. I do take omeprazole and atorvastatin. Also Symbicort and albuterol. What else should I be asking my doctors? My blood pressure is slightly high, GP wants me to consider medication for that. I want to stay active. Doctors seem puzzled when I say the chest tightness goes away when I’m walking hard. I don’t think it’s asthma, and I did feel really good when I know my iron and hemoglobin were higher.

    • Hi MW,
      Thanks for your comment.
      If you have excluded blood loss as a possible cause of your iron deficiency anaemia, I would suggest to also exclude malabsorption of iron from the bowel by checking Anti-endomysial antibody (EMA) and tissue transglutaminase antibody (tTG) levels.

  • Rose

    I had a CBC and it showed slight stomatocytes, however, I had a repeat test done three weeks later, but I do not see anything that suggests stomatocytes are still present. What could that mean?

    Thank you!

    • Hi Rose,
      Thanks for your comment.
      Acquired Stomatocytosis can be found in normal individuals (3–5%).
      The most consistent association is between stomatocytosis and chronic liver disease and/or heavy alcohol consumption.
      They shouldn’t cause concern if the blood indices are normal and you are not anemic.

  • Rose

    Thank you very much for your response.

  • Lesley Heywood

    I have been told that I have MDS following blood tests done after a GI bleed. The blood test results showed: RBC 3.81 – MCV 103.6 – MCH 35.2 – PLATELETS 91.
    Blood tests showed macrocytosis with stomatocytes present.
    Doctor says that I have MDS.
    Bone marrow biopsy results showed ? fingerprinting film in both liquid and ‘hard’ marrow test of lymphocytes being present?
    Alcohol intake really quite low.
    Non smoker for 25 years.
    Low platelet count has been present for 30 years following a massive viral infection acquired whilst on holiday in the Gambia resulting in 6 months of work. (unheard of to take time off work for me)
    Was contacted by the NHS following a visit to the hotel in London at the same time that the Russian ‘spy’ was in contact with polonium poisoning????
    Any comments would be gratefully accepted please.

    • Hi Lesley,
      Thank you for reaching out. I understand your concern about the MDS diagnosis.
      To provide a more accurate assessment, I would need to review the complete bone marrow biopsy report.
      Additionally, it’s important to rule out other potential causes of macrocytosis such as B12/Folate deficiency, liver disease, and underactive thyroid.
      Please send me the complete report so that I can assist you further.
      Your long-standing low platelets could be immune-mediated or drug-related.

Leave a Reply

Your email address will not be published. Required fields are marked *