A 56-year-old construction worker presents with dry cough.
Ill-defined curvilinear opacities are seen projecting over both lung fields predominantly in the mid and lower zone with sparing of the apices.
Answer: 2. Asbestos-related pleural plaques.
- Chronic exposure to asbestos (in the form of inhalation of fibers) can cause a number of neoplastic and non-neoplastic manifestations in the chest and pleural cavity [1,2]. The constellation of these manifestations is termed as asbestos-related diseases.
- Occupational exposure to asbestosis is seen in[1,2]:
- Mining and processing
- Insulation manufacturing
- Textile manufacturing
- Manufacture and repair of gaskets and brake linings.
- Manifestations of long-term asbestos exposure include:
- Pleural effusions: Earliest pleural-based phenomenon [1, 2]. These can be hemorrhagic and tend to recur .
- Pleural plaques: Areas of pleural fibrosis commonly involving the parietal pleura, especially the posterolateral and lateral chest wall with sparing of the costophrenic angles [1,2]. Calcification is seen only 10-15% percent of the cases but bilateral calcified pleural plaques are very specific for asbestos exposure .
- Diffuse pleural thickening: This is a non-specific finding and is a result of fusion of the visceral and parietal pleura following multiple benign pleural effusions . Unlike plaques, thickening involves both parietal and visceral pleura [1,2].
- Round Atelectasis:
- Secondary to inflammatory, fibrosis and subsequent in folding of the pleural fold into the lung as it matures and contracts [1,2].
- It is seen as a rounded pleural based peripheral opacity with a typical comet tail/crow feet appearance of the adjacent Broncho vascular structures going into the mass [1,2].
- Pulmonary fibrosis secondary to long-term asbestos exposure (usually more than 20 years).
- Imaging features are non-specific and include areas of ground-glass opacification with small nodular opacities and ill-defined diaphragmatic contours. HRCT shows subpleural fibrotic strands in early phase along with the above features [1, 2].
- Malignant mesothelioma
- Commonly affects the pleura, however can also affect the peritoneum and pericardium.
- This has a long latency period of more than 30 years and a poor prognosis [1,2].
- Imaging features include generalized lobulated thickening of the pleura with decreased volume of the hemithorax. It often extends along the fissures and invades into adjacent mediastinal structures [1, 2].
- Bronchogenic carcinoma
- Norbet C, Joseph A, Rossi SS, Bhalla S, Gutierrez FR. Asbestos-Related Lung Disease: A Pictorial Review. Curr Probl Diagn Radiol. 2015;44:371–82. [PubMed]
- Roach HD, Davies GJ, Attanoos R, Crane M, Adams H, Phillips S. Asbestos: when the dust settles—an imaging review of asbestos‐related disease. Radiographics 2002; 22: S167–84.