Which radiographic finding is most characteristic of asbestos exposure?

• A. Left calcified pleural plaques
• B. Left calcified hilar lymph nodes
• C. Diffuse interstitial fibrosis
• D. Pleural effusion

Answer: (A)

Calcified plaques along the parietal pleura are the radiographic finding most characteristic of asbestos exposure. These plaques form from fibrous collagen deposition on the pleural surfaces, particularly the diaphragmatic and lateral chest walls, and they become calcified over time. Their presence on chest radiographs is a strong historical clue to prior asbestos exposure, even if lung function is normal or symptoms are absent.

Other findings can occur with asbestos exposure but are less specific. Diffuse interstitial fibrosis, or asbestosis, shows a basilar, reticular interstitial pattern indicating parenchymal fibrosis rather than pleural involvement. Pleural effusions can accompany asbestos exposure but are not as distinctive. Calcified hilar lymph nodes can occur but do not represent the hallmark feature of asbestos exposure.