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Pleural plaques are areas of thickened tissue in the pleura around the lungs. They are the most common sign of asbestos damage to the chest cavity but may not develop for decades after the exposure. Plaques do not typically cause symptoms and don’t necessarily cause malignant pleural mesothelioma.
About Pleural Plaques
One of the potential consequences of ongoing asbestos exposure is the formation of pleural plaques. Pleural plaques are areas of thickened, fibrous tissue in the pleura that surrounds the lungs and chest cavity. Other facts about pleural plaques include:
- The formation of pleural plaques is the most common asbestos pleural disease.
- They occur in about 50% of people with heavy and prolonged past exposure.
- The latency period for pleural plaque development after asbestos exposure can be as short as ten years but is often 20 years or longer.
- Although plaques don’t develop into mesothelioma, they are an indicator of risk.
- Plaques typically form in the parietal layer of the pleura, sometimes along the diaphragm, and rarely in the visceral pleura or between the ribs.
- Calcified pleural plaques often occur over time, with calcium salts accumulating in and hardening the plaques.
- While pleural plaques often cause no symptoms, pleural calcification can create a grating sensation.
Pleural Plaques Are Caused by Asbestos Exposure
Asbestos, the natural material once used extensively in construction, shipbuilding, and other industries, has caused untold damage for those exposed to it.
If you worked around asbestos during your career, you might have inhaled loose fibers of this material. Once inhaled, these tiny microscopic fibers quickly become lodged in the body’s tissues. Most often, they lodge in the pleura of the chest cavity.
Asbestos fibers in the body may cause damage over time. Not everyone exposed to asbestos will experience tissue damage; however, pleural plaques are quite common among those who do.
A plaque occurs when asbestos fibers cause tissue to become fibrous and stiff. Exactly why this happens is not fully understood but is likely related to inflammation and scar tissue caused by asbestos fibers.
Pleural plaques are the most common complications of asbestos exposure. Low levels of exposure can trigger their formation as compared to conditions like asbestosis and mesothelioma. Research also suggests that plaque development is slow and may not be visible on imaging scans until many years after initial asbestos exposure.
How Pleural Plaques Form
Researchers do not understand exactly how these plaques form. They may be caused by inflammation and scar tissue, but there may be other pathways to their development.
For example, some experts hypothesize that asbestos fibers trigger an immune system response. This may cause a type of immune cell called a macrophage to visit the site of damage, causing a reaction that leads to fibrosis and hardening of the tissue.
Pleural Plaques versus Pleural Thickening
Pleural thickening is another common result of asbestos damage to the pleura. This condition is easily confused with pleural plaques:
- Plaques are small, spaced apart, asymptomatic, and typically benign.
- Thickening tends to be more widespread. It likely affects the entire pleural surface and worsens over time.
Symptoms also typically accompany pleural thickening and get worse as the condition progresses.
Symptoms of Pleural Plaques
Most people with pleural plaques only experience mild symptoms if they have symptoms at all. Some research has found that people with plaques have slightly diminished lung capacity and function. Rarely a person with pleural plaques experiences chest pain and difficulty breathing.
Diagnosing Pleural Plaques and Mesothelioma
Most people diagnosed with pleural plaques had no symptoms leading up to diagnosis. Often, diagnosis is made after a patient has a chest X-ray done for other reasons. X-rays and CT scans are most commonly used to image and diagnose pleural plaques:
- Plaques may appear on the X-ray image even though they are not causing symptoms. Calcified plaques are easier to see and present as whitish deposits. If plaques are discovered on your X-ray, talk to your doctor about your risk for mesothelioma. Further tests can see if you have early signs of cancer.
- A better way to get a look at abnormal tissue and identify it as a plaque is a CT scan. CT scans provide a clearer picture of thickened tissue, even non-calcified plaques.
A biopsy is necessary when it is unclear if it is an abnormality, plaque, or cancerous growth. A small sample of the abnormal tissue is taken, usually through the insertion of a long needle, then examined under a microscope. A pathologist will look at the cells in the sample to determine if they are malignant or benign.
How Are Pleural Plaques Treated?
For most people diagnosed with pleural plaques, no treatment is necessary. The plaques are unlikely to cause symptoms or progress. However, if doctors discover you have plaques, it is important to reduce risk factors for related diseases like mesothelioma.
If you still work with asbestos, take steps to eliminate that exposure. If you are a smoker, it is time to quit. Ask your doctor for advice on other measures you can take to minimize your risks. If you have symptoms, your doctor can prescribe medications or therapies that may help.
Can Pleural Plaques Become Malignant?
The prognosis for pleural plaques is generally positive. There is no evidence that plaques will develop into mesothelioma or lung cancer. Still, plaques are a risk factor for these types of cancer because they indicate you were likely exposed to asbestos.
Any exposure to asbestos puts you at risk for later developing mesothelioma. Monitor your symptoms, reduce risk factors, and see your doctor for regular screenings.
Can I Get Compensation for Pleural Plaques?
Mesothelioma is not the only asbestos disease that qualifies for compensation. Pleural plaques strongly indicate past asbestos exposure, so they count toward benefits in most situations.
If you served in the military and developed plaques after active duty asbestos exposure, you can file a VA claim for benefits. The rating and benefits will not be as high as for more debilitating illnesses.
If you worked for a company that exposed you to asbestos, you can sue for compensation. If the company formed a trust, you can file for benefits. Asbestos trusts recognize pleural plaques as a level I asbestos disease.
Pleural plaques are not usually serious health problems and are unlikely to cause debilitating symptoms; however, plaques should be considered a wake-up call. They could be a sign that asbestos may have been in your workplace, causing exposure and increasing your risk of mesothelioma. If you get sick with other related conditions, find out how a mesothelioma lawyer or asbestos trust fund could help you get compensation.Get Your FREE Mesothelioma Packet
Page Medically Reviewed and Edited by Anne Courtney, AOCNP, DNP
Anne Courtney has a Doctor of Nursing Practice degree and is an Advanced Oncology Certified Nurse Practitioner. She has years of oncology experience working with patients with malignant mesothelioma, as well as other types of cancer. Dr. Courtney currently works at University of Texas LIVESTRONG Cancer Institutes.