Medicine:Pleural plaque

thumb|Macroscopic appearance of a pleural plaque. Pleural plaques are indicators of asbestos exposure, and the most common asbestos-induced lesion. They usually appear after 20 years or more of exposure and never degenerate into mesothelioma. They appear as fibrous plaques on the parietal pleura, usually on both sides, and at the posterior and inferior part of the chest wall as well as the diaphragm.