Asbestos

Etiology

  • Asbestos exposure

Clinical Presentations

Pulmonary Manifestations

  • Asbestosis (ILD)

Tobacco: 13x increased risk of asbestosis in smokers (compared to non-smoking asbestos-exposed cohort)
– Household exposure to clothes of spouse or parent: increases risk of asbestosis
– Latency:
– Benign Asbestos Pleural Effusion: may occur within 10 years of exposure (this is the shortest latency period for any of the asbestos-related lung manifestations)
– Asbestosis, pleural plaques, and asbestos-related lung cancer: typically occur 20 years or more after exposure
– Malignant mesothelioma: usually occurs 30 years of more after exposure

Diagnosis
– Pleural fluid: exudate
– Appearance:
– pH:
– Cell count/diff: PMN or mononuclear-predominant/eosinophilia seen in 52% of cases
– Culture:
– FOB: >1 asbestos bodies/hpf suggests asbestos exposure (but does not confirm asbestosis)
– Should do BAL in basilar segments to obtain asbestos bodies (due to gravity effect of deposition)
– CXR/Chest CT patterns:
– Interstital infiltrates: lower-lobe predominance
– Honeycombing: small cystic changes (seen best in lower fields) seen late in course
– Radiographic honeycombing correlates well with pathologic honeycombing
– Diaphragmatic pleural calcifications/ asbestos plaques: indicate history of asbestos exposure only and have no significance (they may become more numerous or grow over time)
– Asbestos pleural effusion: usually small-moderate and unilateral (bilateral in only 10% of cases)
– Rounded atelectasis:
– HRCT: picture mimics that of IPF
– More sensitive than CXR, especially in patients with subtle ILD and non-calcified pleural plaques
– Serum autoantibodies: may be seen
– Hypergammaglobulinemia: may be seen

Pathologic Patterns
– Desquamative Interstitial Pneumonia (DIP):
– Usual Interstitial Pneumonitis (UIP):

  • Asbestos Pleural Effusion: associated with asbestos exposure (may be brief, intermittent, or in distant past: incidence increases with increasing exposure load)

    • Incidence: 3% of exposed cases
    • Latency: mean of 30 years (few cases reported to occur within 5 years)
    • Usually asymptomatic (66%) but may present with
    • Diagnosis: requires F/U for >2 years to be certain effusion is benign
    • Natural history: usually resolves without consequence but may be recurrent (may develop fibrothorax)
  • Pleural Plaques

  • Mesothelioma

  • Lung Cancer

Other Manifestations

  • xxx

Treatment

  • xxx

References

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