Introduction to Pleural Disease

The chapter titled introduction to pleural disease discusses the imaging and clinical features of diseases of the pleura. The pleural space is a potential space located between the visceral and parietal pleural surfaces. Pleural effusion and pneumothorax are the most common manifestations of pleural disease and are caused by a wide variety of disease processes. Pleural thickening may be related to benign or malignant processes. Bilateral discontinuous nodular pleural thickening is characteristic of pleural plaques. Pleural thickening with calcification may also be seen in fibrothorax. Malignant pleural disease may manifest with pleural effusion, pleural nodules or masses, or a combination of the two. There are several CT features suggestive of malignant pleural thickening including circumferential pleural thickening, pleural nodules or masses, involvement of the mediastinal pleural surface, and pleural thickening measuring greater than 1 cm in thickness. Metastatic disease is the most common pleural neoplasm. Mesothelioma is uncommon but remains the most common primary pleural malignancy and is almost always seen in patients with previous asbestos exposure. Pleural abnormalities must be differentiated from pulmonary processes. Pleural masses may exhibit obtuse angles with the adjacent pleural surfaces, displace rather than engulf adjacent pulmonary vasculature, and may exhibit the incomplete border sign.