Pleural Plaques and Pleural Thickening

Pleural plaques and pleural thickening are common signs that someone has breathed asbestos. Both are scarring of the pleura, the thin lining around the lungs, caused by asbestos fibers that reached the surface of the lung decades earlier. But the two are not the same, and the difference matters. Pleural plaques are usually harmless on their own and rarely cause symptoms, though they're reliable evidence that you were exposed to asbestos. Diffuse pleural thickening is more extensive and can stiffen the lung enough to make breathing difficult. Either finding is worth understanding, for your health and for your legal rights, and we'll review your situation at no cost. Call 833-4-ASBESTOS.

What the pleura is, and what asbestos does to it

The pleura is a two-layered membrane that wraps each lung and lines the inside of the chest wall, with a thin film of fluid between the layers that lets the lung glide as you breathe. When asbestos fibers are inhaled, some work their way to the edge of the lung and into this lining, where the body can't clear them. Over decades, the irritation drives the slow buildup of scar tissue. Depending on how that scarring forms, it shows up as plaques or as thickening.

Pleural plaques

Pleural plaques are areas of thickened, often hardened tissue on the pleura, and they're the single most common consequence of asbestos exposure. They tend to be small, discrete, and scattered, and they're frequently found by accident, on a chest X-ray or CT scan ordered for something else entirely. Most people who have them never know until a scan turns them up.

The defining thing about plaques is that they usually cause no symptoms, and for most people they don't noticeably affect breathing. Studies of large groups have measured a small average reduction in lung volume in people with plaques, but most people with plaques alone have normal breathing tests. They are not cancer, they do not become cancer, and on their own they rarely affect how a person feels or breathes. What they do tell you is important, though: plaques on both sides of the chest are a reliable fingerprint of past asbestos exposure, often the first hard evidence a person has that they were exposed at all.

Do pleural plaques raise your cancer risk?

A lot of what's written about pleural plaques overstates the danger with respect to lung cancer. Plaques are not cancer and do not turn into it. Whether having them adds to your lung cancer risk, beyond what the asbestos exposure itself does, has been genuinely debated. In a large 2020 study of heavily exposed people, once researchers accounted for how much asbestos each person had actually breathed, having plaques added no measurable lung cancer risk on its own.² A large French study came out the other way: people with plaques still had a higher risk of dying of lung cancer after adjusting for smoking and their estimated exposure, a difference that may come down to how precisely each study measured exposure.⁴ Mesothelioma is a separate question. In that French group, plaques were also linked to a higher mesothelioma risk after adjusting for exposure, but that finding rested on a small number of cases, and whether plaques add risk beyond the exposure itself is still debated.⁵ None of this means plaques turn into cancer. The practical message is steady: plaques are a sign of the asbestos exposure that carries the risk. That's exactly why finding them should prompt two things, a careful reconstruction of your exposure history and regular medical follow-up: periodic chest imaging and breathing tests, and low-dose CT lung cancer screening if you meet the screening criteria. We can help with the first. Our free health test, a chest X-ray read by a certified B-reader, documents changes in the lung lining and gives your own doctor a starting point for follow-up, but it isn't lung cancer screening and doesn't replace low-dose CT for those who qualify.

Pleural thickening

Diffuse pleural thickening is the more serious of the two conditions. Instead of discrete patches, the scarring spreads across the pleura, and because it tends to involve the layer that hugs the lung itself, it can act like a tightening shell, limiting how fully the lung can expand. Sometimes it follows an earlier asbestos-related fluid buildup around the lung (a benign asbestos pleural effusion); sometimes it appears on its own.

Unlike plaques, diffuse pleural thickening can cause readily apparent symptoms. People with significant thickening often notice breathlessness on exertion and a reduced exercise tolerance, and lung-function testing may show a restrictive pattern, especially when the thickening is extensive, meaning the lungs hold and move less air than they should. It's this potential to impair breathing that makes pleural thickening medically and legally weightier than plaques. Pleural thickening can also occur alongside asbestosis, the scarring of the lung tissue itself, though the two are separate conditions.

(Two asbestos-related conditions of the pleura, the lining around the lungs, shown side by side. Pleural plaques (left) are discrete, often calcified patches on the chest-wall lining and diaphragm; they mark past asbestos exposure but usually leave the lung free to expand. Pleural thickening (right) is a diffuse, continuous layer of scarring that wraps the lung, restricts its movement, and often blunts the sharp angle where the lung meets the diaphragm. That difference is why thickening is the more likely of the two to affect breathing, and to matter in a claim.)

How they're diagnosed

Both conditions are usually found through imaging. A chest X-ray can reveal plaques and thickening, especially once plaques calcify, and a CT scan shows them in far more detail and is better at telling the two apart and at distinguishing real disease from harmless anatomy. Because plaques are so often symptomless, they're frequently discovered incidentally. For pleural thickening, doctors add pulmonary function testing to measure whether and how much breathing has been affected, which matters both for treatment and, as discussed below, for any claim.

A credible history of asbestos exposure is part of the picture too. Plaques and diffuse thickening are strongly associated with asbestos, and classic plaques on both sides of the chest, in someone with a history of exposure, are confidently attributed to it.^1,3 Changes on only one side, or a single isolated patch, can also follow an old infection such as tuberculosis, a chest injury, bleeding into the chest, or surgery, and doctors rule those out before attributing the finding to asbestos. Diffuse thickening in particular has more possible causes than plaques do. This is one reason a thorough exposure history is worth doing carefully rather than quickly.

Treatment

No medicine can reverse plaques or pleural thickening, because the scarring is permanent; only in rare, severe cases of thickening can surgery remove a constricting layer, as described below. For pleural plaques, that's rarely a problem, since they usually don't affect breathing; the standard approach is periodic monitoring rather than active treatment, to keep an eye out for other asbestos-related changes over time.

Diffuse pleural thickening is managed according to how much it limits a person. When breathing is significantly affected, the same supportive measures used for other fibrotic lung conditions apply, including pulmonary rehabilitation and, in more advanced cases, supplemental oxygen. In rare, severe cases where a thick layer of scar traps the lung, surgeons may consider removing it (decortication), a decision made case by case. As with asbestosis, quitting smoking and staying current on flu and pneumonia vaccines protect the lung function that remains.

Compensation for pleural disease

Here the difference between the two conditions matters most, and we'll be straight with you about it.

Pleural plaques on their own usually pay little. Many trusts recognize plaques on both sides of the chest at their lowest disease levels, without any breathing impairment, but the scheduled values there are small, and after the trust's payment percentage the check is often smaller still. Higher trust levels, and many states' laws for filing a lawsuit, require measured impairment on breathing tests, which plaque-only cases usually can't show. We'd rather tell you that now than raise false hopes.

But plaques still matter legally, for two reasons. They are hard evidence that you were exposed to asbestos, which is the foundation of any asbestos claim. That matters most if cancer ever follows: at most trusts, a lung cancer or other asbestos-related cancer claim (colon, stomach, throat, or esophagus) pays full value only with documented asbestosis or bilateral pleural disease, so plaques on your chart can be what qualifies the claim. They don't show whose products you worked around, which a claim also has to prove, but if you later develop an impairing condition or an asbestos cancer, the medical record of your exposure is already there. How you handle an early claim matters, though: signing a general release, or the date a condition was diagnosed, can affect a later claim and its deadlines, so talk to us before filing anything.

Diffuse pleural thickening is a different story. When it impairs your breathing, measured objectively on lung-function testing, it can support meaningful compensation through asbestos trust claims and lawsuits, much as asbestosis does, and the more it limits you, the stronger the claim. If it keeps you from working, it may also qualify you for Social Security Disability, a separate federal program with its own lung-function thresholds and work-history requirements. And because pleural disease so often travels with other asbestos conditions, it's worth having someone look at the whole picture, your plaques or thickening, your exposure history, and any sign of asbestosis, lung cancer, or mesothelioma.

If you've been told you have either condition, a free review will tell you where you actually stand, today and down the road.

Talk to us

You focus on your health. We'll take care of the rest.

A note on your chart that says "pleural plaques" or "pleural thickening" is easy to set aside, but it's worth a closer look. It usually means asbestos reached your lungs, and that's worth understanding, both for keeping an eye on your health and for protecting your rights if anything develops later. Call 833-4-ASBESTOS or contact us here for a free, no-obligation review. There's no fee unless we win.

When my family was exposed to asbestos, no one was looking for the early signs, and by the time anyone understood what had happened, it was too late to act. A pleural plaque or a note about thickening on your chart is one of those early signs: proof that asbestos reached you, and a chance to watch your health and protect your rights before anything worse develops. We built this site so that families get that chance early, instead of learning the truth the way mine did, too late to do anything about it.

— Justinian C. Lane, Founding Partner

References

1. American Thoracic Society. Diagnosis and initial management of nonmalignant diseases related to asbestos. Am J Respir Crit Care Med. 2004;170(6):691-715.
2. Brims FJH, Kong K, Harris EJA, et al. Pleural plaques and the risk of lung cancer in asbestos-exposed subjects. Am J Respir Crit Care Med. 2020;201(1):57-62. doi:10.1164/rccm.201901-0096OC
3. Wolff H, Vehmas T, Oksa P, Rantanen J, Vainio H. Asbestos, asbestosis, and cancer, the Helsinki criteria for diagnosis and attribution 2014: recommendations. Scand J Work Environ Health. 2015;41(1):5-15. doi:10.5271/sjweh.3462
4. Pairon JC, Andujar P, Rinaldo M, et al. Asbestos exposure, pleural plaques, and the risk of death from lung cancer. Am J Respir Crit Care Med. 2014;190(12):1413-1420. doi:10.1164/rccm.201406-1074OC
5. Pairon JC, Laurent F, Rinaldo M, et al. Pleural plaques and the risk of pleural mesothelioma. J Natl Cancer Inst. 2013;105(4):293-301. doi:10.1093/jnci/djs513