Pleural plaques are discrete, localized areas of thickened, often calcified tissue on the pleura — the lining of the lungs and chest wall. They are the most common sign of past asbestos exposure and serve as a reliable marker that a person inhaled asbestos fibers, usually decades earlier.

What Pleural Plaques Are

Plaques are patches of fibrous, sometimes calcified tissue that form on the parietal pleura (the layer lining the chest wall) and on the diaphragm. They typically appear 20 to 40 years after asbestos exposure. Unlike diffuse pleural thickening, plaques are localized and usually do not significantly affect lung function.

Symptoms

Pleural plaques usually cause no symptoms at all. Most are discovered incidentally on a chest X-ray or CT scan performed for an unrelated reason. When calcified, they are readily visible on imaging.

Are Pleural Plaques Dangerous? Do They Cause Cancer?

Pleural plaques themselves are benign — they are not cancer and do not turn into cancer or mesothelioma. However, they are an unmistakable indicator of asbestos exposure, and people with plaques have had the kind of exposure associated with an elevated risk of mesothelioma, asbestos-related lung cancer, and asbestosis. For that reason, a diagnosis of pleural plaques is a reason for ongoing medical monitoring, not alarm about the plaques themselves.

Why They Matter

Because pleural plaques confirm asbestos exposure, they are medically and legally significant even without symptoms. If you are told you have pleural plaques, make sure your physician documents your asbestos-exposure history and establishes a monitoring plan, since your exposure carries longer-term risks that warrant watching.


If you were diagnosed with pleural plaques, mesothelioma, or another asbestos-related condition and were exposed to asbestos at work, in the military, or in a building, you may be entitled to compensation through asbestos trust funds and civil litigation.

This information is educational, drawn from sources such as the American Cancer Society and National Cancer Institute, and is not medical advice. Consult your own physician about diagnosis and monitoring.