Mysterious pleural effusions

Our plain-English summary of Mysterious pleural effusions (Lancet, 1982).

The study

• Journal: Lancet
• Published: 1982;1(8283):1226
• Type of article: Editorial
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001782).

In plain English

This was an unsigned editorial in The Lancet, not a new study. It reviewed published reports on pleural effusions (fluid around the lung) with no obvious cause. It first discussed tuberculosis, viral infections and connective-tissue diseases, then asbestos as a more recently recognised cause of benign effusion. It described a study by Epler and co-workers of 1135 asbestos-exposed workers and 717 non-exposed university employees. That study found 34 benign pleural effusions in the exposed group and none in the controls, and incidence rose from 0.7 to 9.2 per 1000 person-years with increasing asbestos exposure. The editorial stated that the time from first exposure to effusion was usually under 20 years. It said many effusions caused no symptoms and passed, and that diagnosis rested on exposure history and ruling out other causes. In follow-up reports it cited, 4 of 13 Australian men later had mesothelioma, and in a group of 34, 1 had mesothelioma after 6 years. The editorial concluded that the numbers were too small and follow-up too short to assess the risk of lung cancer or mesothelioma after a benign effusion.

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: Unsigned editorial (narrative review of published reports); no original data
• Who was studied: No study population of its own. The main study discussed (Epler and co-workers) covered 1135 asbestos-exposed workers and 717 non-exposed university employees.
• Exposure: Asbestos exposure in general; the editorial does not name fiber types, products or jobs
• Main results:
  • In the Epler study cited, 34 benign pleural effusions were found in the asbestos-exposed population and none in the control population
  • In that study, effusions were called benign if no malignant tumour developed within 3 years
  • In that study, incidence of pleural effusion rose from 0.7 to 9.2 per 1000 person-years with increasing degrees of asbestos exposure
  • The editorial stated that the time from first asbestos exposure to pleural effusion was usually less than 20 years and sometimes less than 10 years
  • The editorial stated that many effusions were symptomless and transient, so true incidence was likely higher than prevalence surveys showed
  • The editorial stated that diagnosis was based on exposure history and exclusion of other causes
  • In a cited comparison of 31 benign effusions and 24 due to mesothelioma, pain or blood in the fluid was not more common with mesothelioma, but large or recurrent effusions were more likely to be due to mesothelioma
  • In a cited follow-up of 13 Australians with benign asbestos effusions, 4 went on to mesothelioma and 2 to lung cancer, and asbestosis was present or developed in 6
  • In a cited Australian study of 22 men with benign effusions, no malignant tumours were seen (the follow-up length is unreadable in the text)
  • Of 34 men followed for up to 27 years, 18 had residual diffuse pleural thickening, 8 had recurrent effusions, and 1 had mesothelioma after 6 years
• The authors' conclusion: The editorial concluded that the numbers were too small and follow-up too short to assess the risk of lung cancer or mesothelioma developing after a benign asbestos effusion. It also said a later mesothelioma may be unrelated to the effusion, or a precursor may have been present all along.
• Limitations the authors state:
  • The editorial stated that the follow-up evidence available was too small and too short to judge later cancer risk

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Effusion.

Related studies

• Asbestos pleural effusion — E.A. Gaensler, A.I. Kaplan (1971)
• Usefulness of Claudin 4 in the cytological diagnosis of serosal effusions — S. Lonardi, C. Manera, et al. (2011)
• Immunocytochemical staining of serous effusions with the monoclonal antibody Ber-EP4 — M. De Angelis, I.D. Buley, et al. (1992)
• Diagnostic value of total and differential leukocyte counts in pleural effusions — T. Pettersson, H. Riska (1981)
• The role of liquid-based cytology and ancillary techniques in pleural and pericardic effusions: an institutional experience — E.D. Rossi, T. Bizzarro, et al. (2015)
• Deletion status of p16 in effusion smear preparation correlates with that of underlying malignant pleural mesothelioma tissue — T. Hida, S. Matsumoto, et al. (2015)

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