Posterior Parietal Pleural Plaques: A Case Report

Background: Pleural plaques are accumulations of hyalinized collagen fibers in the parietal pleura. These deposits are considered pathognomonic for asbestos exposure. Macrophage phagocytosis of short asbestos fibers promotes increased collagen production by fibroblasts. The exact pathogenesis of pleural plaques is unknown, but it is presumed that they form secondary to the lungs attempt to remove asbestos fibers from the pleural spaces through lymphatic channels located exclusively in the parietal pleura. Pleural plaques are most often identified via radiographic imaging and physical images of these structures are rare. Case information: During routine dissection of a 76-year-old male cadaver, multiple pleural plaques were discovered on the posterior parietal pleura of the chest cavity bilaterally. Of note, the pleural plaques discovered were found more medially than usually reported in the literature and the pleural plaques seen in the right posterior chest cavity extended much higher, to the 3rd rib, than is usually reported in the literature. Conclusions: Pleural plaques act as markers of asbestos exposure and can, in rare instances, cause chest pain, coughing, and dyspnea. Patients who have been exposed to asbestos are at increased risk for malignant mesothelioma, lung cancer, and asbestosis. Identification and confirmation of pleural plaque presence may aid patients in seeking compensation for asbestos exposure. Clinical findings of pleural plaques may indicate need for further testing and patient monitoring. This report aims to broaden awareness of a sign of asbestos exposure and inform clinicians about patient populations in which further health surveillance is warranted.