Question 12.1

A 21-year-old African American female has been admitted with mild dyspnoea and severe back and abdominal pain. Pulse oximetry on room air is 94%.

Full Blood Count report is as follows:



Normal Adult Range

White Cell Count*

16.52 x 109/L

4.0 – 11.0


82 g/L

115 – 155


529 x 109/L

150 – 400



0.40 – 0.54

Mean Corpuscular Volume

93.5 fL

79 – 99

Red Cell Count*

2.47 x 1012/L

4.5 – 6.5

Mean Corpuscular


33.2 pg

27 – 34

Mean Corpuscular

Haemoglobin Concetration

355 g/L

320 – 360

Neutrophils %


40 – 80

Blood film comment:

Target cells – occasional 
Spherocytes – occasional 
Sickle cells – occasional 
Neutrophilia with toxic granulation

  • Give the most likely explanation of her signs and symptoms.
  • Briefly describe your management of this problem.
  • List three other conditions associated with the presence of target cells on the blood film.

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College Answer


Sickle cell crisis


Ensure adequate ABC – in particular supplemental oxygenation to keep saturations above 96% 
IV fluids 
Adequate analgesia

Investigate possible precipitants.



Iron deficiency

Spleen removal

Liver disease


Deficiency of enzyme lecithin cholesterol acyl transferase


This is a sickle cell crisis.

What makes it so? well, the sickle cells are a dead giveaway.

The precipitants?

  • Infection
  • Hypoxia,
  • Exposure to cold
  • Dehydration
  • Physical exertion,
  • Acidosis
  • Extensive trauma or injury
  • Psychological stress

Management of a sickle cell crisis depends somewhat on what sort of crisis it is. They come in vasoocclusive, aplastic and sequestration flavours.

All will require oxygen, analgesia and rehydration.

Most will require blood transfusion.

As for target cells:

You will see lots of target cells in

  • Thalassemia
  • Hepatic disease with jaundice
  • Hemoglobin C disorders
  • Postsplenectomy

Fewer target cells are seen in

  • sickle cell anemia
  • iron deficiency
  • lead intoxication
  • Deficiency of enzyme lecithin cholesterol acyl transferase


Okpala, Iheanyi E. "Sickle cell crisis." Practical Management of Haemoglobinopathies (2004): 63-71.

Walker, H. Kenneth, et al. "Peripheral blood smear." (1990). in Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition.

Bessis, Marcel. "Codocytes and Target Cells." Corpuscles. Springer Berlin Heidelberg, 1974. 59-64.

Jones, Kathy W. "Evaluation of Cell Morphology and Introduction to Platelet and White Blood Cell Morphology." I do not know which textbook this is form, but it is a chapter which is available for free online ... for now.

Bull, BRIAN S., J. Breton-Gorius, and E. Beutler. "Morphology of the erythron."New York, McGraw Hill (2001): 271-288. - this is an online re-posting of a chapter of Williams' Haematology, but without the figures.