Non-hemolytic normocytic anemia: Pathology review

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Non-hemolytic normocytic anemia: Pathology review



Non-hemolytic normocytic anemia: Pathology review

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A 3-month-old infant is brought to the clinic by her concerned parents. She was born at 39-weeks gestational age via a spontaneous vaginal delivery, and past medical history is non-contributory. The patient is at the 30th percentile for length and below the 10th percentile for weight. Temperature is 36.6°C (97.9°F), pulse is 130/min, respirations are 42/min, and blood pressure is 90/63 mmHg. Physical exam reveals increased distance between the eyes, a flat nasal bridge, and triphalangeal thumbs. Laboratory testing is obtained, and the results are shown below:

Which of the following is most likely to be seen on histological analysis of this patient’s bone marrow aspiration?

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At the family medicine center, Sofia, a 32-year-old black person of African descent, came to visit the doctor because she has been feeling fatigue as well as exertional dyspnea.

Her medical history includes systemic lupus erythematosus.

Next to Sofia, a father from Ireland brings his 14-year-old son, John, who’s been less active and has bruised easily for the past month.

John’s medical history includes recurrent upper respiratory tract infections before the onset of the current symptoms.

During the clinical examination, his spleen cannot be palpated.

CBC is ordered for both people and they show low hemoglobin with normal MCV and reticulocyte count index lower than 2%.

John also has leukopenia and thrombocytopenia.

Both John and Sofia are suffering from anemia, which is defined as lower than average levels of hemoglobin, typically below 13.5 grams per deciliterg/dL in adult men and below 12.0 g/dL in adult women.

For children, this level varies based on the age.

Now, anemias can be broadly grouped into 3 categories based on mean corpuscular volume, or MCV, which reflects the volume of an RBC.

So, microcytic anemia is where the MCV is lower than 80 femtolitersfL, normocytic is when, with an the MCV is between 80 and 100 femtolitersfL, and macrocytic is when the, with an MCV is larger than 100 femtolitersfL.

Alright, the normocytic anemias can be further classified as hemolytic where there’s increased destruction of red blood cells and non-hemolytic where there’s decreased production of red blood cells in the bone marrow.

When there’s hemolysis, the bone marrow revs up and starts pumping out reticulocytes which are immature red blood cells, but when there’s a bone marrow problem the reticulocyte count is low.

So for your exams, if you run into a normocytic anemia and the reticulocyte production index, or RPI, is higher than 2%, think hemolytic anemia, since the red blood cells are being destroyed and the body compensates by producing more.

If it’s a non-hemolytic anemia, the reticulocyte production index is lower than 2% since the anemia is caused by a decrease in red blood cell production.

Now, in this video, let’s focus on the nonhemolytic normocytic anemias, which are basically anemia of chronic disease and aplastic anemia.


  1. "Kaplan USMLE Step 2 CK Lecture Notes Internal Medicine" Kaplan Medical (2017)
  2. "Robbins Basic Pathology" Elsevier (2017)
  3. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  4. "Treatment of Anemia in Patients With Heart Disease: A Clinical Practice Guideline From the American College of Physicians" Annals of Internal Medicine (2013)
  5. "Aplastic Anemia" New England Journal of Medicine (2018)
  6. "Anemia of Chronic Disease" New England Journal of Medicine (2005)
  7. "Regulation of erythropoietin production" The Journal of Physiology (2011)
  8. "Guidelines for the diagnosis and management of adult aplastic anaemia" British Journal of Haematology (2015)
  9. "Pure red cell aplasia" Blood (2016)

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