Multiple pleural plaques. II

Our plain-English summary of Multiple pleural plaques. II, by H.C. Anton (The British Journal of Radiology, 1968).

The study

• Author: H.C. Anton
• Journal: The British Journal of Radiology
• Published: 1968;41(485):341-8
• Cited by: 23 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 002725).

Abstract

A total of 40 cases of multiple pleural plaques is now analysed. The incidence is given of predominantly calcified, and predominantly non-calcified plaques. In addition to the faint shadow sign of the non-calcified plaque, the importance of the profile opacity is stressed. This may be the only sign in some cases. The concept of classical asbestosis is regarded with misgivings, and a re-interpretation is suggested of the ground-glass appearance. The scope and limitations of radiology in lesions due to asbestos inhalation are discussed. Associated neoplasms are illustrated.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

This 1968 paper by a Glasgow radiologist analysed chest X-rays from 40 patients with multiple pleural plaques. Twelve came from the author's earlier paper and 28 were new, most seen during routine reporting over six months. Of 32 patients interviewed, 30 gave a work history suggesting asbestos exposure. Seventeen were shipyard or boiler-shop workers, several of whom had not handled asbestos themselves. No fiber types were named. Plaques were mainly calcified in 22 cases, mainly non-calcified in 15, and balanced in three. Counting every case with any non-calcified plaques, the total was 24 of 40. In three cases only plaques seen edge-on at the side of the lung were visible. There were six cancers inside the chest across the 40 cases, and one patient had abdominal fluid suggesting a possible peritoneal mesothelioma. Most of these diagnoses had not been confirmed by surgery or post-mortem. The author concluded that plaques allow asbestos exposure to be diagnosed with confidence if talc and mica exposure is ruled out. The author noted that some non-calcified plaques may have been missed, and that another factor, such as smoking, could explain an individual cancer.

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: Case series: radiological analysis of chest X-rays of patients with multiple pleural plaques, with summarised case reports
• Who was studied: 40 patients with multiple pleural plaques on chest X-rays at the X-ray Department, Stobhill General Hospital, Glasgow: 12 from the author's first paper plus 28 new cases. Cases already diagnosed as asbestosis were excluded. Two patients were female. On interview, 30 of 32 patients had a work history suggesting asbestos exposure, with indirect exposure in shipyards accepted.
• Exposure: Occupational asbestos exposure; no fiber types named. The group included 17 shipyard and boiler-shop workers (several of whom worked near laggers and insulators rather than handling asbestos), two joiners with occasional asbestos roofing or boarding work, and two people who had worked in an asbestos factory.
• Main results:
  • Of the 40 cases, plaques were predominantly calcified in 22 (four of the multinodular type) and predominantly non-calcified in 15; in three there was a balance between the two.
  • Six of the 22 mainly calcified cases also showed less conspicuous non-calcified plaques, so 24 of the 40 cases showed non-calcified plaques in total (stated in the addendum).
  • In three cases only the plaques seen in profile (edge-on at the side of the lung fields) were visible.
  • Strands of fibrous tissue at the lung bases were found in only five of the cases, even though all had obvious pleural plaques.
  • There were six intrathoracic neoplasms in the combined series of 40 cases.
  • One further patient in the second series presented with gross ascites, and the author suggested the possibility of a peritoneal mesothelioma; the author described this diagnosis as speculative.
• The authors' conclusion: The author concluded that the radiological signs of multiple pleural plaques are specific enough to diagnose exposure to asbestos with confidence, provided the work history excludes inhalation of talc and mica.
• Limitations the authors state:
  • In the first year of the study the author was not aware that non-calcified plaques could be diagnosed, so some such cases may have been missed.
  • For five of the six malignant cases in the second series, surgical or post-mortem confirmation had not yet been obtained, and the peritoneal case remained speculative.
  • Malignancy in an individual case could have been due to another factor, such as smoking.

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: Pleural Plaques, Neoplasm.

Related studies

• Pleural plaques: a signpost of asbestos dust inhalation — E.N. Sargent, G. Jacobson, et al. (1977)
• Calcified interlobar pleural plaques: visceral pleural involvement due to asbestos — E.N. Sargent, J.S. Felton, et al. (1981)
• Calcified plaques on mediastinal pleural reflections associated with asbestos dust exposure: four case reports — A. Solomon, G.K. Sluis-Cremer, et al. (1984)
• Calcified plaque in the superior portion of the major fissure. An unusual manifestation of asbestos exposure — S.B. Rupp, H. Jolles (1989)
• CT demonstration of interlobar fissure calcification due to asbestos exposure — S.D. Rockoff (1987)
• Pleural fibrocalcific plaques and asbestos exposure — L.O. Meurman (1968)

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