Table 2 Clinical characteristics of asbestos-related diffuse pleural thickening
From: Clinical consequences of asbestos-related diffuse pleural thickening: A review
Prevalence | 5–13.5% of asbestos exposed people 3–34 years following first asbestos contact |
|---|---|
Latency | Variable but can occur within 1 year of a benign asbestos associated pleural effusion. Usually 15–20 years |
Frequency | Increases from the time of first exposure |
Pathogenesis | Uncertain. Possible sequela of benign asbestos associated pleural effusion, recurrent bouts of asbestos related pleuritis or extension of parenchymal fibrosis into the pleura |
Location | Usually bilateral, 1/3rd are unilateral Can extend to encase the lung, obliterating the pleural spaces, the fissures and the costophrenic recesses |
Macroscopic appearance | Arises from the visceral pleura. Pale grey diffuse thickening of visceral pleura that may become adherent to the parietal pleura. Not sharply demarcated from the pleura, unlike pleural plaques. |
Microscopic appearance | Collagenous fibrous tissue |
Symptomatology | Chest pain, dyspnea. Hypercapnic respiratory failure and death in severe cases |
Pulmonary function | Restrictive defect. Reduction in static lung volumes and compliance. Reduced transfer coefficient (TLCO) but a raised or maintained TLCO when corrected for alveolar volume (KCO) |
Chest x-ray appearance | Smooth non interrupted pleural density extending over at least 1/4th of the chest wall Obliterates the costophrenic angles |
HRCT appearance | A continuous sheet of pleural thickening more than 5 cm wide, more than 8 cm in craniocaudal extent and more than 3 mm thick |
Associated features | Rounded atelectasis, parenchymal bands |
Treatment | Supportive, symptomatic, non invasive ventilation for respiratory failure |
Differential diagnosis | Any cause of acute pleuritis can cause diffuse pleural thickening (see table 1). Chest trauma and surgery, Mesothelioma, other pleural based tumours, pleural plaques. |