This medical illustration provides a detailed cross-sectional view of the thoracic cavity, emphasizing the thickening and irregularity of the pleural lining characteristic of pleural mesothelioma. The image is intended for educational purposes to support understanding of how malignant cells invade the pleural space, affecting lung function. Pleural mesothelioma most often results from prolonged exposure to asbestos fibers and is a particularly aggressive form of cancer affecting the lining of the lungs.