Pleural disease and asbestos

What is pleural disease?

The pleura is a thin double-layered membrane that lines the outside of each lung and the inside of the chest wall. Asbestos fibres inhaled decades earlier can lodge in and near the pleura, causing chronic inflammation that leads to a range of non-malignant conditions collectively called benign asbestos-related pleural disease.

The main forms

• Pleural plaques. Localised areas of fibrous thickening on the parietal pleura, usually asymptomatic and often the earliest visible sign of asbestos exposure on imaging.
• Diffuse pleural thickening. A more extensive fibrosis of the pleura that can restrict lung expansion and reduce lung function.
• Benign asbestos pleural effusion. Accumulation of fluid between the pleural layers, often the first pleural manifestation to appear after exposure (typically within 10-20 years).
• Rounded atelectasis. A benign lung collapse associated with pleural fibrosis, often picked up incidentally on imaging.

Latency and symptoms

Pleural changes typically appear 20-40 years after first exposure. Plaques are usually asymptomatic. Diffuse pleural thickening can cause shortness of breath and chest discomfort. A pleural effusion may present with breathlessness on exertion or a dull chest ache.

Diagnosis

Chest X-ray and CT imaging are the primary diagnostic tools. Pleural plaques often show characteristic calcification patterns. Diagnosis usually involves your family physician, a respirologist, and imaging review by a radiologist experienced in occupational disease.

Is it cancer?

Non-malignant pleural disease is not mesothelioma or cancer, and it does not always progress to cancer. However, the presence of pleural plaques or thickening indicates significant past asbestos exposure and warrants ongoing medical follow-up because that same exposure raises the risk of asbestos-related cancers.