What are pleural plaques?
Pleural plaques are collections of hyalinized collagen in the parietal pleura, and are a common benign finding of prior asbestos exposure. These are virtually pathognomonic for confirming prior asbestos exposure, and typically appear more than 20 years after such exposure. When noncalcified, they appear as small plateau-shaped areas of pleural thickening when seen in profile and may mimic pulmonary nodules when seen en face. They often calcify, however. When visualized tangentially on a chest radiograph, a linear or curvilinear calcification along the pleural surface is seen, whereas when seen en face, irregular linear, stippled, or geographic calcification overlying the hemithorax is seen
