Pleural lesions and the ILO classification: the need for a revision

Our plain-English summary of Pleural lesions and the ILO classification: the need for a revision, by G. Hillerdal (American Journal of Industrial Medicine, 1991).

The study

• Author: G. Hillerdal
• Journal: American Journal of Industrial Medicine
• Published: 1991;19(1):125-30
• Cited by: 10 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. 003747).

Abstract

The ILO system for radiographic classification of pneumoconioses is a very important epidemiological tool. Unfortunately, the classification is not precise for pleural lesions, which are especially important for evaluation of asbestos-related diseases. The classification cannot separate extrapleural fat from diffuse thickening of the pleura, nor large plaques from diffuse thickening. In this paper, a short review of the different lesions are given and a revised scheme is suggested. This scheme includes as separate lesions: pleural fat; lesions of the parietal pleura, i.e., pleural plaques; and lesions of the visceral pleura, i.e., diffuse thickening and rounded atelectasis. The extent and width, as in the present ILO scheme, could be abolished.

In plain English

This was a commentary by a single author about the ILO system for classifying chest X-rays of pneumoconioses, the lung diseases caused by dust. It reported no new data from patients or workers. Instead, it gave a short review of pleural lesions (changes in the lining around the lungs) and proposed a revised pleural section of the system. The author argued that the existing system could not separate extrapleural fat from diffuse pleural thickening, nor large plaques from diffuse thickening. It also did not classify rounded atelectasis at all. The proposed scheme recorded three separate groups: pleural fat; plaques on the parietal pleura; and lesions of the visceral pleura, including costophrenic angle obliteration, diffuse thickening, crow's feet, rounded atelectasis and apical pleural thickening. The author wrote that pleural plaques are practically pathognomonic for asbestos exposure, meaning they practically identify it. Readers of X-rays should state whether they believe lesions are due to asbestos. The author proposed abolishing the width and extent measurements, seriously considering the lateral view, and leaving out oblique views. The author noted the system is not intended for evaluating individuals for compensation.

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: Commentary with a short narrative review and a proposed revision of the pleural part of the ILO classification; no original data
• Who was studied: No study population; the subject was the ILO system for classifying radiographs of pneumoconioses (1980 guidelines), particularly its handling of pleural lesions
• Exposure: Asbestos exposure in general, as a cause of pleural lesions on chest radiographs; no specific fiber types, jobs or doses were studied
• Main results:
  • The author argued the existing classification cannot separate extrapleural fat from diffuse pleural thickening, nor large plaques from diffuse thickening
  • The author noted that rounded atelectasis is not classified in the existing system, although in most cases it results from asbestos-related pleural abnormalities
  • The proposed scheme records pleural fat, parietal pleural plaques and visceral pleural lesions as separate lesions
  • The author considered the current measure of the extent of calcification rather meaningless and suggested recording only whether calcification is present
  • The author stated that pleural plaques are practically pathognomonic for asbestos exposure, while other pleural lesions are more non-specific
  • The author proposed that readers state, after classifying lesions, whether they believe them to be due to asbestos
  • The author recommended serious consideration of including the lateral view in the next revision
  • The author recommended that oblique views not be included in the classification, although they can be clinically valuable
  • The author noted the ILO system is not intended for evaluating individuals for compensation purposes
• The authors' conclusion: The author concluded that the pleural part of the ILO classification needs revision, and that the extent and width measurements of the present scheme could be abolished

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: ILO Classification, Pleura, Parietal Pleura, Pleural Plaques, Visceral Pleura, Rounded Atelectasis.

Related studies

• Semantics and the application of the ILO classification: the need for recording visceral pleural manifestations separately — A. Solomon (2002)
• Asbestos, asbestosis, and cancer: The Helsinki criteria for diagnosis and attribution. Critical need for revision of the 2014 update — X. Baur, H.J. Woitowitz, et al. (2017)
• Does the 1980 ILO classification of pneumoconiosis need a facelift? — K.H. Kilburn (1988)
• The IASLC Mesothelioma Staging Project: Proposals for the M Descriptors and for Revision of the TNM Stage Groupings in the Forthcoming (Eighth) Edition of the TNM Classification for Mesothelioma — V.W. Rusch, K. Chansky, et al. (2016)
• The IASLC Mesothelioma Staging Project: Proposals for Revisions of the N Descriptors in the Forthcoming Eighth Edition of the TNM Classification for Pleural Mesothelioma — D. Rice, K. Chansky, et al. (2016)
• International Analysis of Age-Specific Mortality Rates From Mesothelioma on the Basis of the International Classification of Diseases, 10th Revision — P. Boffetta, M. Malvezzi, et al. (2018)

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