Clinical, radiological, and pathological investigation of asbestosis

Our plain-English summary of Clinical, radiological, and pathological investigation of asbestosis, by T. Kishimoto, K. Kato, H. Arakawa, et al (International Journal of Environmental Research and Public Health, 2011).

The study

• Authors: T. Kishimoto, K. Kato, H. Arakawa, K. Ashizawa, K. Inai, Y. Takeshima
• Journal: International Journal of Environmental Research and Public Health
• Published: 2011;8(3):899-912
• Type of article: Case report
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

By the radiological examination, differential diagnosis of asbestosis from chronic interstitial pneumonia such as IPF/UIP is difficult. The pathological features of asbestosis show the peribronchiolar fibrosis which suggest that asbestos fibers cause the inflammation of bronchioli. Therefore, the criteria for pathological diagnosis of asbestosis in 2010, contain the finding of peribronchiolar fibrosis again. Chest CT scanning including HRCT for total of 38 cases clinically diagnosed asbestosis were reviewed by 3 radiologists and one pulmonologist. On the other hand, the histology of lung tissues obtained by surgery or autopsy were examined by 4 pulmonological pathologists. Furthermore, the content of asbestos bodies in the lung was counted by phase-contrast microscopy. Thirteen cases were definitely diagnosed of asbestosis in the image including HRCT and 17 cases were diagnosed by the histopathological examination showing lung fibrosis with peribronchiolar fibrosis. Only 10 cases were indicated asbestosis by both the radiological and histopathological examinations. The mean value of asbestos bodies for these cases, was 2,133,255 per gram of dry lung tissue.

In plain English

Researchers in Japan reviewed 38 people diagnosed with asbestosis on chest x-ray (ILO classification) whose lung tissue was available from surgery (3) or autopsy (35). All but one were men, and half had worked in dockyards. Three radiologists and a pulmonologist reviewed x-rays and CT scans, four pathologists examined lung tissue, and asbestos bodies were counted per gram of dry lung. Imaging indicated asbestosis in 17 cases and tissue examination in 17 (the discussion says 16), but only 10 cases (26.3%) were indicated by both. Those 10 averaged 1,434,594 asbestos bodies per gram, and all 6 cases judged typical asbestosis exceeded 1,000,000. Twelve cases had no asbestos bodies on tissue slides. Overall, the authors judged 11 cases not to be asbestosis and 4 to be possible asbestosis. They concluded that imaging struggles to tell asbestosis apart from chronic interstitial pneumonia such as IPF/UIP or mixed dust pneumoconiosis, and that disagreement between imaging and tissue findings is a problem. They noted that chrysotile does not easily form asbestos bodies.

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: review of clinically diagnosed asbestosis cases comparing radiological and pathological (tissue) diagnosis, with asbestos body counts
• Who was studied: 38 cases diagnosed as asbestosis (ILO profusion 1/0 or higher) with lung tissue available: 3 surgical cases (asbestosis with lung cancer) and 35 autopsy cases. 37 men and 1 woman, average age 71.6 years. Authors based in Japan; study dates not given.
• Exposure: Occupational asbestos exposure; fiber types not reported. 19 worked in dockyards (10 in ship rigging). Other jobs included 5 asbestos sprayers, 2 insulation workers and 1 asbestos product manufacturer. Average exposure period 30.3 plus or minus 12.52 years.
• Main results:
  • Radiology (x-ray and CT including HRCT) indicated asbestosis in 17 of the 38 cases (44.7%).
  • Tissue examination found fibrosis consistent with asbestosis in 17 cases (44.7%); the discussion elsewhere gives 16 pathologically diagnosed cases.
  • Only 10 of the 38 cases (26.3%) were indicated as asbestosis by both radiological and tissue examination.
  • In the 10 cases indicated by both methods, the average asbestos body count was 1,434,594 plus or minus 901,861 per gram of dry lung tissue.
  • In the 6 cases judged typical asbestosis on both radiology and tissue findings, the average was 2,068,255 plus or minus 568,089 bodies, and every one exceeded 1,000,000 bodies per gram of dry lung tissue.
  • Across all 38 cases, asbestos body counts ranged from 300 to 2,780,000 per gram of dry lung tissue.
  • In 12 of the 38 cases (31.6%), no asbestos bodies were seen in the lung tissue specimens, so these cases did not meet the Helsinki criteria.
  • Six cases with 5,000 or fewer asbestos bodies per gram were diagnosed, based on radiology and pathology, as emphysema accompanied by fibrosis rather than asbestosis.
  • Taking all findings together, the authors concluded that 11 cases were not asbestosis and 4 others were possible asbestosis.
  • 30 of the 38 cases (78.9%) had findings of asbestos exposure such as pleural plaque, and 4 had diffuse pleural thickening.
• The authors' conclusion: The authors concluded that diagnosing asbestosis on imaging is difficult because it must be distinguished from IPF/UIP or mixed dust pneumoconiosis. They also concluded that disagreement between radiological and tissue diagnosis is a problem for diagnosing asbestosis.
• Limitations the authors state:
  • Chrysotile does not easily form asbestos bodies, so the authors stated that the types and numbers of asbestos fibers should be determined.
  • The study focused on autopsy cases; the authors hope to study more cases, including surgical lung cancer cases, on a larger scale.

Topics

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

Medical terms in this study, explained in our Lexicon: Differential Diagnosis, Interstitial, Fibrosis, Inflammation, High-Resolution CT (HRCT), Histology, Autopsy, Asbestos Bodies.

Related studies

• Asbestosis and other pulmonary fibrosis in asbestos-exposed workers: high-resolution CT features with pathological correlations — H. Arakawa, T. Kishimoto, et al. (2016)
• Experimental asbestosis: an investigation of functional and pathological disturbances. II. Results for chrysotile and amosite exposures — D.M. Hiett (1978)
• Radiological and pathological correlations in asbestosis in the Republic of South Africa and the United Kingdom. I. A proposed radiological classification of asbestosis — G.K. Sluis-Cremer, C.P. Theron (1965)
• Radiological and pathological correlations in asbestosis in the Republic of South Africa and the United Kingdom. II. A preliminary study of observer variation in the classification of radiographs of asbestos-exposed workers and the relation of pathology and x-ray appearances — A. Caplan, J.C. Gilson, et al. (1965)
• The relative importance of clinical, radiological and pulmonary function variables in evaluating asbestosis and chronic obstructive airway disease in asbestos workers — G.M. Regan, B. Tagg, et al. (1971)
• Clinical and radiological criteria for the differential diagnosis between asbestosis and idiopathic pulmonary fibrosis: Application in two cases — A. Stufano, A. Scardapane, et al. (2021)

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