Table 2

Clinical characteristics of asbestos-related diffuse pleural thickening

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, 1/3^rd 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 1/4^th 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.

Miles et al. Journal of Occupational Medicine and Toxicology 2008 3:20   doi:10.1186/1745-6673-3-20