Malabsorption syndromes: Pathology review

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Malabsorption syndromes: Pathology review

Gastrointestinal system

Gastrointestinal system


Malabsorption syndromes: Pathology review

USMLE® Step 1 questions

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USMLE® Step 1 style questions USMLE

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A 52-year-old man comes to the physician for evaluation of severe pain affecting several joints. The symptoms began 3 months ago. He has also had loose, greasy stools several times daily as well as a 12-lb weight loss. Past medical history is noncontributory. He is not sexually active and does not consume alcohol or illicit substances. Temperature is 37.0°C (98.6°F), pulse is 82/min, respirations are 14/min, and blood pressure is 130/62 mmHg. Cardiac auscultation reveals a soft, high-pitched, early diastolic decrescendo murmur heard best at the left 3rd intercostal space. The left and right knee are warm and tender to palpation, and passive range of motion is limited bilaterally. Abdominal examination reveals intense epigastric pain on palpation. Generalized lymphadenopathy is present. Biopsy of the small intestine reveals periodic acid-Schiff-positive (PAS)-positive macrophages within the lamina propria. Which of the following is the most likely cause of this patient’s underlying condition?  


At the gastroenterology clinic, there is a 53 year- old man from the United Kingdom, named George, who came in complaining of periodic foul-smelling, bulky and frothy stools, as well as recurrent abdominal pain after meals and weight loss, despite not dieting.

On further history, he admits that he has been consuming alcohol with almost every meal for the last 10 years.

An upright abdominal x-ray shows calcifications in the epigastric area.

Next to him is a 9 year- old girl from Iran, named Yasmin, whose parents are concerned about her short stature and inadequate weight gain despite following a balanced diet.

On examination, her height and weight are below the 3rd percentile for her age and sex.

She also has an itchy rash consisting of small vesicles on both of her knees.

At first glance, you’d think George’s and Yasmin symptoms have nothing in common.

But the fact is, they both have different forms of malabsorption syndromes.

With malabsorption, nutrients are no longer effectively absorbed in the small intestine.

Nutrients can either be macronutrients, such as fats, proteins and carbs or micronutrients like vitamins and minerals.

Malabsorption can either be global, meaning that the absorption of all nutrients is affected, or it can be partial, meaning that only specific nutrients cannot be absorbed.

In general, unabsorbed nutrients are allowed to linger in the gastrointestinal lumen for longer than usual, disrupting the proper formation of stool, which results in diarrhea, bloating and flatulence.

And since these nutrients are lost in the stool, malabsorption will also lead to unintentional weight loss and various nutritional deficiencies.

For macronutrients, let’s start big, with fat malabsorption which causes steatorrhea, meaning fatty, greasy, floating, voluminous and terribly smelling stools.

And it’s important to know that screening for fat malabsorption is done with a fecal fat test, known as Sudan III stain.

A high yield fact to remember is that there will also be a decrease in the absorption of the fat-soluble vitamins; A, D, E, and K, and that might be the only clue you get for fat malabsorption!

So, in a question stem with symptoms like night blindness, eye dryness, corneal ulcerations or thickened skin, think of vitamin A deficiency.


  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Malabsorption Syndromes" Digestion (1998)
  4. "Chronic Diarrhea with Normal Stool and Colonic Examinations" Journal of Clinical Gastroenterology (1991)
  5. "Pancreatic exocrine insufficiency: Diagnosis and treatment" Journal of Gastroenterology and Hepatology (2011)
  6. "Serum lipase activities and pancreatic lipase immunoreactivity concentrations in dogs with exocrine pancreatic insufficiency" American Journal of Veterinary Research (2006)
  7. "Effects of diet on clinical signs of exocrine pancreatic insufficiency in dogs" Journal of the American Veterinary Medical Association (2006)
  8. "Primary Sclerosing Cholangitis" New England Journal of Medicine (2016)
  9. "Primary sclerosing cholangitis: Diagnosis and management" Current Gastroenterology Reports (2006)
  10. "Liver abnormalities in bowel diseases" Best Practice & Research Clinical Gastroenterology (2013)
  11. "Lactose Intolerance in Infants, Children, and Adolescents" PEDIATRICS (2006)
  12. "Milk Intolerance and Microbe-Containing Dairy Foods" Journal of Dairy Science (1987)
  13. "Tropical Sprue in 2014: the New Face of an Old Disease" Current Gastroenterology Reports (2014)
  14. "Environmental enteropathy: critical implications of a poorly understood condition" Trends in Molecular Medicine (2012)

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