The pathology of asbestos related disease

Our plain-English summary of The pathology of asbestos related disease, by J.M. Davis (Thorax, 1984).

The study

• Author: J.M. Davis
• Journal: Thorax
• Published: 1984;39(11):801-8
• Type of article: Review
• Cited by: 32 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001701).

Summary of the article

This review summarised the main conclusions of a symposium on the pathology of asbestos related disease held in Edinburgh on 27 and 28 April 1983. It was attended by British research workers, hospital pathologists, and doctors from the pneumoconiosis medical panels and the asbestos industry. Four topics were covered: lung dust burden and disease, the diagnosis of mesothelioma, present day patterns of asbestosis, and medicolegal attribution of disease to asbestos. Expressed as phase contrast equivalents, fibre counts ranged from 5000 to 100 000 per gram of dried lung in controls without industrial exposure, from 20 000 upwards in mesothelioma, and from below 1 000 000 to 50 000 000 in mild asbestosis. Amphibole counts, but not chrysotile counts, appeared related to asbestosis severity and to mesothelioma. The participants called for standardised techniques and accredited laboratories, and regarded electron microscopy as essential for people exposed only to chrysotile. Histological, staining, cytological and electron microscopic criteria for mesothelioma were described. About 5-10% of the 500 annual UK cases were thought to present serious diagnostic difficulty at necropsy. The classical pattern of advanced asbestosis was now rarely seen in Britain, and a four-grade histological scale was outlined. Opinions differed on whether 1 000 000 or 250 000 fibres per gram (phase contrast) marked the level below which fibrosis was unlikely. Many pathologists favoured apportioning causality rather than an "all or nothing" approach.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This was a review article summarising the main conclusions of a symposium on the pathology of asbestos related disease held in Edinburgh in April 1983. It reported no new study of its own. Drawing on published figures, all converted to the levels phase contrast microscopy would show, the review gave lung fibre counts per gram of dried lung tissue. These ranged from 5000 to 100 000 in control cases without industrial exposure, from 20 000 up to the asbestosis maximum in mesothelioma cases, from below 1 000 000 to 50 000 000 in mild asbestosis, and from 1 000 000 to several hundred million in severe asbestosis. It reported that mesothelioma cases in general had chrysotile counts no higher than controls. It described mesothelioma cases with no asbestos bodies in lung sections yet fibre counts as high as 375 000 per gram. Opinions differed on a threshold for fibrosis (1 000 000 versus 250 000 fibres per gram). The paper concluded that actual lung fibre counts are essential for correctly diagnosing doubtful lesions, particularly in medicolegal cases.

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: Review article summarising presentations and discussion at a symposium; no original study
• Who was studied: No study population. The paper summarised a symposium held in Edinburgh on 27 and 28 April 1983. It was attended by British research workers and hospital pathologists, and by doctors from the pneumoconiosis medical panels and the asbestos industry.
• Exposure: Asbestos in general, with comparisons between chrysotile and the amphiboles (chiefly crocidolite and amosite). It also mentioned tremolite as a contaminant of chrysotile ore, and non-asbestos mineral fibres found in lung tissue.
• Main results:
  • From published figures, all reduced to phase contrast microscopy levels, fibre counts in control cases without industrial exposure to asbestos ranged from 5000 to 100 000 per gram of dried lung tissue.
  • In cases of mesothelioma, counts ranged from 20 000 up to the maximum for asbestosis cases.
  • Mild asbestosis cases ranged from below 1 000 000 to 50 000 000 fibres per gram of dried lung tissue, and severe asbestosis cases from 1 000 000 to several hundred million.
  • Fibre counts for pleural plaques ranged from 500 to 15000 fibres per gram of dried plaque.
  • The review reported electron microscopy studies (cited from other authors) showing two patterns. Cases of mesothelioma in general had chrysotile counts no higher than controls. Amphibole counts appeared related to asbestosis severity and were far higher in mesothelioma cases than in controls.
  • Cases of mesothelioma had been recorded where several lung sections showed no asbestos bodies, yet lung fibre counts were as high as 375 000 per gram of dried tissue.
  • Only 5-10% of the 500 mesotheliomas occurring annually in the United Kingdom were thought to present serious diagnostic difficulties at necropsy.
  • Citing an earlier cytology study, the review reported two findings for mesotheliomas later proved. Only 15% had been wrongly diagnosed as other tumours on exfoliative studies. Up to 25% of effusions from mesotheliomas confirmed at necropsy showed only a lymphocytic pattern or were acellular.
  • The classical pattern of advanced asbestosis was now rarely seen in Britain. Only 29 deaths with asbestosis as the sole cause were recorded in Office of Population Censuses and Surveys figures for 1979.
  • Opinions differed on a fibre threshold for fibrosis. Some pathologists suggested 1 000 000 fibres per gram by phase contrast microscopy as the level below which fibrosis is unlikely. Others believed 250 000 fibres per gram should be accepted.
• The authors' conclusion: The paper concluded that actual lung fibre counts are essential for the correct diagnosis of doubtful lesions, particularly in medicolegal cases.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis.

Medical terms in this study, explained in our Lexicon: Pathology, Pneumoconiosis, Mesothelioma, Attribution, Amphibole Group, Chrysotile, Autopsy, Fibrosis.

Related studies

• Assessment of mineral fibres from human lung tissue — J.M. Davis, B. Gylseth, et al. (1986)
• Fiber counting and analysis in the diagnosis of asbestos-related disease — A. Churg (1982)
• The enigmatic asbestos body: its formation and significance in asbestos-related disease — A. Morgan, A. Holmes (1985)
• Diseases associated with asbestos exposure. Diagnostic perspectives in forensic pathology — T. Ehrenreich, I.J. Selikoff (1983)
• Problems in the pathology of disease caused by asbestos — F. Whitwell (1978)
• Chest ultrasonography in health surveillance of asbestos-related lung diseases — A. Smargiassi, G. Pasciuto, et al. (2017)

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