The presentation and natural history of asbestos-induced diffuse pleural thickening

Our plain-English summary of The presentation and natural history of asbestos-induced diffuse pleural thickening, by V. Jeebun, S.C. Stenton (Occupational Medicine, 2012).

The study

• Authors: V. Jeebun, S.C. Stenton
• Journal: Occupational Medicine
• Published: 2012;62(4):266-8
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Three forms of asbestos-related benign pleural disease are recognized: discrete pleural plaques, pleural effusions and diffuse pleural fibrosis. Of these, diffuse pleural fibrosis is the most significant on account of its chronicity and associated morbidity.

Aims: The objectives of this study were to determine the latency of asbestos-induced diffuse pleural fibrosis, its presenting features and its clinical course once established.

Methods: We conducted a retrospective review of 75 patients with asbestos-induced diffuse pleural fibrosis referred for assessment at our institution from 1992 to 2007. Diffuse pleural fibrosis was considered to be present if there was obliteration of the costophrenic angle in continuity with at least 3-mm pleural thickening, in accordance with the International Labour Organization 2000 Classification.

Results: The median latency for development of diffuse pleural fibrosis from first asbestos exposure was 34 years. Seventy-three per cent of patients had unilateral disease at presentation and 24% of these were observed to develop contralateral disease after a median of 2 years. Unilateral pleural disease was commonest on the right. Forty per cent of patients presented with pleural effusions preceding the development of diffuse pleural thickening. The median latency for development of pleural effusions from onset of exposures was 38 years. Eighty per cent of the pleural effusions were unilateral. Once established, pleural thickening was reported to have remained stable in 91% on the ipsilateral side.

Conclusions: The findings of this study may help in providing further insight into the natural history of diffuse pleural fibrosis to guide the clinician in the management of this condition.

In plain English

This retrospective review studied 75 men with occupational asbestos exposure and diffuse pleural thickening, referred for assessment during litigation to the authors' UK institution from 1992 to 2007. The article does not say which asbestos fiber types these 75 men were exposed to. For the 44 men with good evidence of when the disease began, the median time from first asbestos exposure to diffuse pleural thickening was 34 years. At presentation, 73% had thickening on one side only. Of these, 24% later developed it on the other side, after a median of 2 years. One-sided disease was most often on the right (32 of 42 cases). In 40%, the thickening was preceded by pleural effusions (fluid around the lung). The effusions appeared a median of 38 years after exposure began and resolved after a median of 7 months. Once established, the thickening stayed stable on the same side in 68 cases (91%). The authors noted limitations: referral depended on litigation and an established diagnosis, and only a quarter had CT scans. The authors concluded the findings may give further insight into the condition's natural history.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective review of patient records (case series)
• Who was studied: 75 men engaged in asbestos litigation who were referred for assessment of asbestos-related diffuse pleural thickening at the authors' institution in the UK, 1992 to 2007. Mean age 65 years. All were retired. Cases with tuberculosis, trauma or suspected malignant mesothelioma as a likely alternative explanation were excluded.
• Exposure: Occupational asbestos exposure. The fiber types these men were exposed to are not stated. Table 1 gives a mean of 13 years of exposure (range 0.25 to 39). Exposure sites were shipyards 46%, construction 26%, industrial 18% and mixed 5%.
• Main results:
  • Among the 44 subjects with good evidence of disease onset, the median latency from first asbestos exposure to diffuse pleural thickening was 34 years (range 11 to 67).
  • The authors reported that the disease developed more than 40 years after exposure began in about 40% of cases.
  • 72% reported exertional breathlessness at diagnosis. In about half of them, the breathlessness could also be attributed to other heart or lung illnesses.
  • 27% presented with non-anginal chest pain and 11% with flu-like symptoms.
  • 73% of patients had one-sided disease at presentation. Of these, 24% developed disease on the other side after a median of 2 years (range 1 month to 13 years).
  • One-sided pleural disease was most common on the right (32 of 42 cases).
  • In 40% of patients, diffuse pleural thickening was preceded by pleural effusions.
  • The median latency for pleural effusions was 38 years (range 11 to 55).
  • 80% of the effusions were one-sided (20 right-sided).
  • The effusions resolved after a median of 7 months (range 1 to 24), leaving diffuse pleural fibrosis.
  • Once established, diffuse pleural thickening remained stable on the same side in 68 of 75 cases (91%).
  • In 3 cases, the depth of thickening increased by up to 3 mm over 4 years. No information was available for the remaining 4 cases.
• The authors' conclusion: The authors concluded that the findings may provide further insight into the natural history of diffuse pleural fibrosis to guide clinicians in managing the condition.
• Limitations the authors state:
  • Referral depended on an already established diagnosis of asbestos-induced diffuse pleural thickening.
  • Not everyone with the disease would have engaged in litigation or been referred, so the group may not include all cases.
  • Diagnosis relied mainly on chest radiographs. Only a quarter had a CT scan, which the authors say is more accurate.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis, Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Diffuse Pleural Thickening, Pleural Plaques, Pleural Effusion, Fibrosis, Latency, Costophrenic angle, Pleural Thickening, Asbestos Exposure.

Related studies

• Natural history of pleural thickening after exposure to crocidolite — N.H. de Klerk, W.O. Cookson, et al. (1989)
• Asbestos-related diffuse pleural thickening — N. Fujimoto, K. Kato, et al. (2014)
• Development, radiological zone patterns, and importance of diffuse pleural thickening in relation to occupational exposure to asbestos — H. Bohlig, A. Calavrezos (1987)
• Diffuse pleural thickening in asbestos workers: disability and lung function abnormalities — C.R. McGavin, G. Sheers (1984)
• Asbestos-related pleural diseases: dimensional criteria are not appropriate to differentiate diffuse pleural thickening from pleural plaques — J. Ameille, M. Matrat, et al. (2004)
• A retrospective study on radiological findings of diffuse pleural thickening with benign asbestos pleural effusion in Japanese cases — T. Kishimoto, K. Kato, et al. (2022)

Browse more research in Occupational Medicine, or return to medical research.