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Pleural Thickening and Asbestos

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Pleural thickening occurs when the lining of the lungs thickens with scar tissue. The presence of pleural thickening is a sign of serious and significant asbestos exposure and is associated with mesothelioma cancer and pleural effusions. Pleural thickening is usually first spotted through a chest X-ray, but a CT scan can detect the condition earlier.

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What Is Pleural Thickening?

Pleural thickening is an asbestos-related disease that, as the name implies, thickens the pleura with scar tissue.

Early pleural thickening has no symptoms, however, as more and more rigid pleural scarring forms around the lungs, it becomes harder for them to fully expand when breathing.

As the disease progresses, patients commonly experience chest pain and breathlessness, which is also known as dyspnea.

Pleural Thickening Facts

  • Symptoms may include chest pain and breathing difficulty.
  • Caused by asbestos exposure and associated with pleural effusions.
  • Also caused by conditions that inflame the pleural lung lining.
  • Treated with medication and pulmonary rehabilitation.

Is Pleural Thickening Serious?

Pleural thickening can be serious, especially when it reaches more advanced stages.

The presence of pleural thickening is not enough to confirm a pleural mesothelioma diagnosis, but it can be a sign of serious and significant asbestos exposure.

Because catching mesothelioma in an early stage can lead to a wider range of treatment options, patients with asbestos-related pleural thickening should seek regular cancer screening.

Advanced pleural thickening may close off the space between the two layers of the pleura and encase the lung completely, causing restrictive lung disease. As a result, patients experience decreased lung volume and have to work harder to breathe.

Pleural thickening should not be confused with pleural plaques, another condition caused by asbestos exposure.

What Causes Pleural Thickening?

The cause of pleural thickening is often prolonged exposure to asbestos. When a person inhales asbestos dust, the microscopic mineral fibers can become embedded in the pleura.

This triggers an inflammatory response that causes a chronic accumulation of fluid in the pleural space. This buildup is called a pleural effusion. The progressive collection of fibrous scar tissue is known as pleural thickening.

A review of studies on the topic found pleural thickening occurs in 5% to 13.5% of asbestos-exposed workers. The condition may arise within a year of exposure, or it may not arise until decades later.

In most cases, there is a latency period of 15 to 20 years between the initial asbestos exposure and a doctor’s diagnosis of pleural thickening.

Any disease that causes acute inflammation of the pleura can lead to pleural thickening, so it is vital to share your history of possible asbestos exposure with your doctor in order to ensure an accurate and timely diagnosis.

The causes of pleural thickening include:

  • Chronic pneumonia
  • Tuberculosis
  • Empyema, which is an accumulation of pus in the pleura due to infection
  • Hemothorax, which is an accumulation of blood in the pleura due to chest injury
  • Coronary artery bypass grafting surgery
  • Radiation exposure

These other conditions are more likely to be diagnosed as apical pleural thickening, which means they affect only one side of the chest or one lung. Asbestos-related pleural thickening is more commonly diagnosed as biapical pleural thickening, which means it usually affects both lungs.

What Are Common Pleural Thickening Symptoms?

The most common pleural thickening symptom is breathlessness.

In an early study involving patients with moderate to severe pleural thickening, 95.5% complained of breathlessness, 65% described moderate breathlessness, and 11% described severe breathlessness.

A 2017 study identified diminished lung capacity and reduced breathing function among 37 patients with diffuse pleural thickening compared with 21 control patients without the condition.

Pleural Thickening Symptoms

  • Breathlessness
  • Difficulty drawing a deep breath
  • Shortness of breath, even with mild exertion
  • Chest pain when drawing a deep breath
  • Pain with coughing
  • Dull, chronic chest pain
  • Reduced pulmonary function
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How Is Pleural Thickening Diagnosed?

The most common way to diagnose pleural thickening is with imaging studies such as X-rays MRIs or CT scans.

Doctors can use a few different imaging scans to diagnose pleural thickening:

X-ray Imaging Scans

The condition is usually first spotted through a chest X-ray, in which pleural thickening appears as an irregular shadow on the pleura and extends over at least 25% of the chest wall.

CT Scans

Pleural thickening can be seen on computed tomography scans. CT scans can be used to diagnose pleural plaques and asbestosis, too. CT scans can detect early signs of pleural thickening when scar tissue is 1-2 mm in thickness.

PET and MRI Scans

Doctors can use positron emission tomography scans and magnetic resonance imaging scans to distinguish between pleural thickening and pleural mesothelioma cancer, which can affect patients at the same time.

How Is Pleural Thickening Treated?

Although pleural thickening treatment is typically limited to supportive and symptomatic care, some case reports have shown pleurectomy surgery to be effective in progressive cases.

This aggressive treatment, usually reserved for patients with pleural mesothelioma, involves removing parts of the pleura and surrounding the lungs.

In most cases, doctors provide treatments that address each person’s particular symptoms.

For example, prescription medications such as bronchodilators and steroids can make breathing easier for patients.

The best treatments ease the symptoms of pleural thickening and improve quality of life.

Pulmonary Rehabilitation

According to a 2015 Australian study, pulmonary rehabilitation can significantly improve quality of life for patients with dust-related respiratory diseases, including pleural thickening.

This type of rehabilitation involves moderate-intensity exercise training to help patients overcome their breathing difficulty and stay physically active.

Smoking Cessation

For patients who smoke, quitting is essential after a diagnosis of pleural thickening. Smoking reduces lung function and increases the risk of developing other respiratory diseases.

Talk to your doctor about quitting smoking. They can offer supportive care and additional options, such as nicotine replacement and medications, to curb nicotine urges. Following these steps can improve your odds of successfully quitting for good.

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Registered Nurse and Patient Advocate

Karen Selby joined in 2009. She is a registered nurse with a background in oncology and thoracic surgery and was the regional director of a tissue bank before becoming a Patient Advocate at The Mesothelioma Center. Karen has assisted surgeons with thoracic surgeries such as lung resections, lung transplants, pneumonectomies, pleurectomies and wedge resections. She is also a member of the Academy of Oncology Nurse & Patient Navigators.

Walter Pacheco, Managing Editor at
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8 Cited Article Sources

The sources on all content featured in The Mesothelioma Center at include medical and scientific studies, peer-reviewed studies and other research documents from reputable organizations.

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Last Modified April 23, 2020

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