- Clinical science
Asbestosis is a type of pneumoconiosis caused by the inhalation of asbestos fibers that occurs primarily as a result of occupational exposure. This condition exhibits nonspecific symptoms after a long latency period, e.g. coughing and dyspnea, which are caused by fibrotic changes in the lungs. Diagnosis is established based on history of occupational exposure (such as working with textiles, cement, ship-building, insulation) and characteristic changes noted on chest x-ray (reticular opacities and pleural plaques). Long-term exposure to asbestos can lead to complications like fibrosis, respiratory failure, and malignancy (especially bronchogenic carcinoma, and mesothelioma). Pleural effusion may be the first sign of a malignant mesothelioma. Currently, there exists no curative treatment for asbestosis. Supplementary measures like oxygen therapy, prompt antimicrobial treatment of respiratory infections, cessation of exposure, and immunization against influenza and pneumococcal pneumonia make up the management of these cases. A combination of chemotherapy, surgery, and/or radiation therapy is used to manage malignant mesothelioma. However, prognosis is poor with the mean survival time being ∼ 1 year.
- Type of caused by inhalation of asbestos fibers
- Occupations involving the manufacture or demolition of ships, plumbing, roofing, insulators, heat-resistant clothing, and brake-lining
- Inhalation of airborne asbestos fibers into alveoli
- → inflammation and fibrosis of pleural parenchyma
- → risk of carcinogenic effects
A high cumulative dose of asbestos is associated with a higher incidence of asbestosis, while those who smoke have an increased progression of disease (impaired mucociliary clearance)!
Chest x-ray (classification according to the International Labor Office): diffuse bilateral infiltrates predominantly in the lower lobes
- Interstitial fibrosis
- Supradiaphragmatic and pleural reticulonodular opacities/plaques
- In some cases,
- Parenchymal fibrosis (especially basilar, peribronchiolar, and septal)
- Pleural plaques and subpleural linear opacities
- Chest x-ray (classification according to the International Labor Office): diffuse bilateral infiltrates predominantly in the lower lobes
- Pulmonary function test:
- Bronchoalveolar lavage
- Biopsy: : microscopic asbestos (ferruginous) bodies and evidence of fibrosis
- Definition: primarily malignant tumor that develops from mesothelial cells
- Sex: ♂ > ♀ (3:1)
- Age range: ∼ 40–70 years
- Etiology: : secondary to asbestos exposure
- Histological classification: epithelial mesothelioma, sarcomatoid mesothelioma, biphasic mesothelioma (a mix of epithelial and sarcomatoid mesothelioma)
- Localization: Most commonly manifests as pleural mesothelioma; rarely the peritoneal mesothelioma; very rarely the pericardial mesothelioma
- Clinical findings
- Pleurocentesis : bloody (exudative) pleural effusion
- Imaging (Chest x-ray and CT) ;:
Laparoscopy, thoracoscopy, and pleuroscopy with stained biopsy ;: mesothelioma cells and psammoma bodies
- Risk of implantation metastasis is ∼20% .
- It is important to differentiate mesothelioma from adenocarcinoma.
- Treatment: Radiation, with or without chemotherapy (cisplatin and pemetrexed). Surgery (pleurectomy or pneumonectomy) could be indicated in cases with severely impaired pulmonary function
- Prognosis: Poor, with a mean survival time of ∼ 1 year.
- Progressive respiratory failure
We list the most important complications. The selection is not exhaustive.
- The use of asbestos in the US is restricted
- The following products are banned: any new uses of asbestos, corrugated paper, rollboard, commercial or specialty paper, and felt flooring