16th January 2024

Asbestos-related lung disease

Background

Asbestos describes a group of naturally occurring carcinogenic fibres that consist of magnesium silicates found in a variety of construction materials. Blue (crocidolite) asbestos is recognised as the most carcinogenic form of asbestos. Asbestos exposure can precipitate many pulmonary complications, including asbestosis, benign pleural disease, and malignant disease (Mesothelioma and lung cancer).

Pleural disease

Sequelae of asbestos exposure include pleural effusions, pleural plaques, and pleural thickening. These may occur independently or concomitantly. 

Pleural effusions features:

• Duration of time between exposure to onset of effusion is reported as 15 to 46 years
• Usually small and unilateral 
• Pleural fluid is exudative and can be blood-stained
• Other sinister causes such as Mesothelioma and lung malignancy, are to be investigated first; therefore, may require thoracoscopy +/- pleural biopsy
• Prognosis– normally self-resolving, and approximately one-third recur

Pleural plaques (PP) features:

• Benign finding on the parietal pleura 
• Most common manifestation of asbestos exposure
• They appear approximately twenty years after asbestos exposure
• Usually, asymptomatic and incidental findings

Pleural thickening features:

• Visceral pleural thickening secondary to asbestos exposure
• Adhesion of visceral and parietal pleura leading to diffuse pleural thickening (DPT)
• Extensive DPT can lead to restrictive lung disease and symptoms of dyspnoea and chest pain

Mesothelioma:

• Malignant disease of the pleura
• Asbestos exposure accounts for 85% of cases of Mesothelioma in the UK
• Latency period of over 30 years from exposure to presentation
• Chest pain and dyspnoea are the most common presenting symptoms as a result of pleural effusion
• Most common x-ray findings include pleural effusion and pleural thickening
• Prognosis is poor, with an average life expectancy between one to two years from diagnosis

References

• Murphy, D. C. et al. (2020) “A review of malignant pleural mesothelioma in a large North East UK pleural centre,” Pleura and peritoneum, 6(1), p. 20200144. doi: 10.1515/pp-2020-0144.
• Hajj, G. N. M. et al. (2021) “Malignant pleural mesothelioma: an update,” Jornal brasileiro de pneumologia: publicacao oficial da Sociedade Brasileira de Pneumologia e Tisilogia, 47(6), p. e20210129. doi: 10.36416/1806-3756/e20210129.