Extensive Bilateral Pleural Plaques: A Cadaveric Case Study

Pleural plaques are the most common manifestation of asbestos-related pleural disease and function primarily as markers of prior exposure rather than as direct causes of clinically significant symptoms, often appearing several decades after initial contact. They are typically asymptomatic and discovered incidentally on imaging studies or at autopsy, and they initially present as small, well-circumscribed lesions along the parietal pleura, most commonly over the rib surfaces while sparing the intercostal spaces. They may progressively enlarge, coalesce, and undergo calcification over time. Although asbestos exposure is the primary etiology, pleural plaques and pleural calcifications may also arise from prior infections such as tuberculosis or empyema, trauma, hemothorax, end-stage renal disease, or chronic inflammatory and autoimmune conditions such as systemic lupus erythematosus and rheumatoid arthritis, and in some instances they may be idiopathic. Additionally, pleural plaques can be associated with mesothelioma. When extensive, pleural plaques may restrict lung expansion, leading to exertional dyspnea that can progress to dyspnea at rest and, in advanced cases, respiratory insufficiency. During routine cadaveric dissections conducted as part of the preclinical medical curriculum at the Geisinger Commonwealth School of Medicine (GCSOM), Scranton, Pennsylvania, extensive bilateral pleural thickening, predominantly involving the diaphragmatic pleura, was observed in an 89-year-old male cadaver. After the opening of the thoracic cage and removal of the lungs and heart, pleural plaques were identified, examined, and measured. The pleural cavities were relatively free, with minimal adhesions involving the bases of both lungs in the diaphragmatic regions, and any evidence of pleural effusion was likely lost during the dissection process. Small, isolated pleural plaques were also noted along the anterior aspect of the right parietal costal pleura. A small, firm mass was palpated within the anterior border of the right upper lobe. Tissue specimens were obtained from the pleural plaques of the anterior chest wall and diaphragmatic pleura, as well as from the pulmonary mass, for histopathological evaluation. Microscopic examination demonstrated abundant fibrocollagenous thickening of the parietal pleura with adjacent fibro-adipose connective tissue and associated inflammation, without evidence of asbestos fibers. Histological analysis of the pulmonary mass was consistent with acute pneumonia. Pleural plaques are frequently encountered as incidental findings on chest radiographs and computed tomography scans in elderly individuals, particularly those with prior asbestos exposure, yet many such findings remain clinically uninvestigated during life. Establishing an etiology in cadaveric cases poses a significant challenge due to the absence of reliable occupational, environmental, and medical histories. While the histopathologic features observed in this case are consistent with previously published descriptions, the gross anatomical documentation of extensive pleural plaques predominantly confined to the diaphragmatic pleura, including detailed measurements, texture, and imaging, has not been previously reported. Dissemination of these findings aims to enrich anatomical and pathological educational resources, support future research, and deepen the understanding of pleural pathology encountered during cadaveric dissection and medical education.