Retrospective investigation on diagnostic process for benign asbestos pleural effusion (BAPE) using checklist

Our plain-English summary of Retrospective investigation on diagnostic process for benign asbestos pleural effusion (BAPE) using checklist, by T. Kishimoto, N. Fujimoto, K. Mizuhashi, et al (Journal of Occupational Health, 2020).

The study

• Authors: T. Kishimoto, N. Fujimoto, K. Mizuhashi, S. Kozawa, M. Miura
• Journal: Journal of Occupational Health
• Published: 2020;62(1):e12182
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objectives: In Japan, benign asbestos pleural effusion (BAPE) has been eligible for industrial accident compensation since 2003 as an asbestos-related disease despite the lack of good criteria. We compiled a criteria into a checklist of essential items and for excluding other diseases inducing pleural effusion as a diagnosis process.

Method: Thoracentesis was performed in order to confirm the presence of pleural effusion at the initial diagnosis, and 105 suspected BAPE patients were retrospectively examined. We complied a checklist comprising the following diagnostic items: (a) occupational asbestos exposure; (b) confirmation of exudate of pleural effusion; (c) exclusion of pleural effusion with malignant tumors based on negative results of CEA and hyaluronic acid, and cytology of pleural effusion; (d) exclusion of rheumatic, bacterial, and tuberculous pleuritis; (d) radiological findings for exclusion of malignancies; and (e) histopathological findings based on thoracoscopy that exclude malignancies (when thoracoscopy was not performed, there was confirmation that no malignancies were present during 3-month follow-up observation). Cases that satisfied all items were defined as BAPE.

Results: Among the 105 suspected cases, there were five cases that had no occupational asbestos exposure; six cases in which transudate of on pleural effusion; one case each of rheumatoid pleuritis and tuberculous pleuritis; and five cases of pleural mesothelioma based on chest radiography and histopathological findings within 3 months after initial diagnosis. Therefore, we excluded 18 cases from the 105 candidates and determined 87 cases of BAPE.

Conclusion: We consider that six items described above are suitable for diagnosing BAPE.

© 2020 Japan Organization of Occupational Health and Safety. Journal of Occupational Health published by John Wiley & Sons Australia, Ltd on behalf of The Japan Society for Occupational Health.

In plain English

This study re-examined 105 patients at four Japanese hospitals first diagnosed, from 2012 to December 2019, with benign asbestos pleural effusion (BAPE), a non-cancerous fluid build-up around the lung linked to asbestos. The authors re-checked each case against a checklist: occupational asbestos exposure; inflammatory (exudative) fluid; fluid tests and chest imaging excluding cancer; exclusion of rheumatoid, bacterial and tuberculous pleuritis; and a thoracoscopic biopsy showing no cancer or, without thoracoscopy, no cancer in at least 3 months of follow-up. They excluded 18 cases. Five lacked confirmed occupational exposure, six had non-inflammatory (transudative) fluid, one had rheumatoid pleuritis and one had tuberculous pleuritis. The other five proved to be pleural mesothelioma: three sarcomatoid and two epithelioid. In three of those five, an early thoracoscopic biopsy had been negative. The remaining 87 cases, all men aged 60 to 93, were judged to be BAPE. Their main jobs were shipbuilding, then construction, and the median time from first exposure to BAPE was 53.5 years. The article does not name fiber types. The authors concluded that their criteria are suitable for diagnosing BAPE and that 3 months of follow-up is necessary.

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: Retrospective re-review of cases initially diagnosed as BAPE, checked against a proposed diagnostic checklist
• Who was studied: 105 patients initially diagnosed with BAPE at Okayama, Toyama, Yokohama and Tohoku Rosai Hospitals in Japan, from 2012 to December 2019; all male, aged 60 to 96, median age 79 at diagnosis
• Exposure: Occupational asbestos exposure (fiber types not specified). Among the 87 confirmed BAPE cases the main occupation was shipbuilder, followed by construction worker. Exposure term ranged from 2 to 55 years, median 38 years.
• Main results:
  • The checklist required occupational asbestos exposure and exudative effusion as main items. Its sub-items were negative CEA, hyaluronic acid and cytology results in the effusion; exclusion of rheumatic, bacterial and tuberculous pleuritis; radiological exclusion of malignancy; and histopathological exclusion of malignancy by thoracoscopy. Where thoracoscopy was not performed, no malignant tumor had to be found in at least 3 months of follow-up.
  • Of the 105 initial cases, 100 (95.2%) had a confirmed occupational history of asbestos exposure. Four had pleural plaques on imaging without definite occupational exposure, and one had neither. These five were excluded.
  • Thoracentesis was performed in all 105 cases; 79% had bloody effusion
  • Six cases (6%) met none of Light's criteria, were classed as transudative, and were excluded
  • One case with high rheumatoid factors in serum and effusion was later found to have rheumatoid arthritis and was excluded as rheumatoid pleuritis
  • One case with a pleural fluid ADA of 60.5 U/L was found to be tuberculous pleuritis, confirmed by culture, and was excluded
  • 97.5% of cases had pleural plaques, and none had pulmonary asbestosis
  • Five cases were found to be pleural mesothelioma. In three, thoracoscopic biopsy just after initial diagnosis was negative; tumorous pleural thickening appeared during the 3-month follow-up and later biopsy showed sarcomatoid pleural mesothelioma.
  • The other two mesothelioma cases had persistent severe chest pain with negative imaging; thoracoscopic biopsy showed epithelioid pleural mesothelioma
  • After the exclusions, 87 cases were diagnosed as BAPE
  • The 87 confirmed BAPE cases were all male, aged 60 to 93 years, median age 79
  • Among the 87 confirmed cases, latency from first exposure ranged from 18 to 73 years, median 53.5 years
  • Because five diagnoses changed during follow-up, the authors considered a 3-month follow-up period necessary when diagnosing BAPE by exclusion
• The authors' conclusion: The authors concluded that the checklist criteria are suitable for diagnosing BAPE. These criteria are occupational asbestos exposure, exudative pleural effusion, tumor markers in the effusion, bacterial test results, radiological findings and histopathological findings.
• Limitations the authors state:
  • The authors noted that no new diagnostic criteria had been proposed since earlier work, so they could not compare their findings with standard data from previous studies

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: Benign Asbestos Pleural Effusion, Pleural Effusion, Thoracentesis, Asbestos Exposure, Exudate, Hyaluronic Acid, Cytology, Thoracoscopy.

Related studies

• Clinical Investigation of Benign Asbestos Pleural Effusion — N. Fujimoto, K. Gemba, et al. (2015)
• A retrospective study on radiological findings of diffuse pleural thickening with benign asbestos pleural effusion in Japanese cases — T. Kishimoto, K. Kato, et al. (2022)
• Diagnostic usefulness of tumour marker levels in pleural effusions of malignant and benign origin — F. Kuralay, Z. Tokgöz, et al. (2000)
• Diagnostic accuracy and safety of semirigid thoracoscopy in exudative pleural effusions in Denmark — F. Willendrup, U. Bodtger, et al. (2014)
• Significance of secretory leukocyte peptidase inhibitor in pleural fluid for the diagnosis of benign asbestos pleural effusion — T. Kishimoto, Y. Kojima, et al. (2021)
• Pleural irregularities and mediastinal pleural involvement in early stages of malignant pleural mesothelioma and benign asbestos pleural effusion — K. Kato, K. Gemba, et al. (2016)

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