00:00 / 00:00




Respiratory system

Apnea and hypoventilation

Apnea of prematurity

Sleep apnea

Pleura and pleural space disorders


Pleural effusion





0 / 8 complete

USMLE® Step 1 questions

0 / 1 complete

High Yield Notes

12 pages



of complete


USMLE® Step 1 style questions USMLE

of complete

A 65-years-old man comes to the clinic due to the gradual onset of chest pain, dyspnea, and night sweats for the past 2 months. He also reports a nagging non-productive cough for which he tried over the counter cough syrup with no relief. He does not drink alcohol but has smoked a pack of cigarettes daily for the past 40 years. Temperature is 37.0 °C (98.6 °F), pulse is 80/min, respirations are 20/min, and blood pressure is 135/85 mmHg. On physical examination, decreased air movement and unilateral dullness to percussion at the lung base are noted on the left side. Computed tomography is obtained and shown below:

Retrieved from: Wikimedia Commons

This patient’s condition is most likely associated with which of the following occupational exposures?  

External References

First Aid








Mesothelioma p. NaN

Pleural effusion p. 302

mesothelioma p. NaN


Mesothelioma is an aggressive cancer that attacks the mesothelium, which is a thin membrane made of epithelial cells that lines all of the body’s organs as well as body spaces like the thoracic cavity and abdominal cavity.

Mesothelioma most often develops in the lining of the lungs and pleural cavity, and is well known for its association with the carcinogen asbestos.

In fact, the late Hollywood actor Steve McQueen is well-known for having developed mesothelioma after years of asbestos exposure while in the military.

The vast majority of mesothelioma cases stem from asbestos exposure.

Asbestos is a mineral that was widely used as construction material in everything from paint to insulation to roofing tiles because it has strong fibers that were resistant to fire and served as good insulation.

Asbestos fibers are jagged in shape, and extremely tiny - about 500 times finer than a human hair.

If those tiny asbestos fibers get inhaled over time, they make their way into the interstitial space of the lungs and then slowly make their way over to the epithelial cells of the visceral or parietal pleura - both of which are layers of mesothelium.

The microscopic, jagged asbestos fibers are so small that they can get tangled up with the cell’s chromosomes.

At that point, they can damage the DNA causing a variety of mutations, which ultimately allow those epithelial cells to divide uncontrollably, turning into a tumor.

Over time, small cancerous growths called mesothelial plaques start to cover the visceral pleura over the lungs and the parietal pleural under the chest wall.

Interestingly, these growths start to express a lot of calretinin, a calcium-binding protein, involved in regulating calcium levels within the cell - this is something that helps to distinguish mesotheliomas from other types of tumors.

In addition to affecting the lungs and pleural lining, asbestos fibers can also end up in the stomach if saliva containing the material or mucus from the airways is swallowed.


  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine" McGraw Hill Education/ Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
  5. "Malignant pleural mesothelioma: an update on diagnosis and treatment options" Therapeutic Advances in Respiratory Disease (2016)
  6. "Lung Parenchymal Mechanics" Comprehensive Physiology (2011)
  7. "Calretinin is essential for mesothelioma cell growth/survival in vitro: A potential new target for malignant mesothelioma therapy?" International Journal of Cancer (2013)

Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Cookies are used by this site.

USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.