What is the significance of non-specific pleuritis? A trick question

Our plain-English summary of What is the significance of non-specific pleuritis? A trick question, by J. Janssen, F. Maldonado, M. Metintas (The Clinical Respiratory Journal, 2018).

The study

• Authors: J. Janssen, F. Maldonado, M. Metintas
• Journal: The Clinical Respiratory Journal
• Published: 2018;12(9):2407-2410
• Cited by: 30 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Non-specific pleuritis (NSP) is defined as fibrinous or inflammatory pleuritis which cannot be attributed to a specific benign or malignant etiology. It can be diagnosed in biopsies in up to 30% of cases of exudative pleuritis after thoracoscopy, with a mean of 19.2%. In 66 out of 469 (14.2%) patients in combined series, a malignant pleural disease (mostly mesothelioma) was found during a follow-up of at least 21 months. Most likely, a follow-up time of 12 months is sufficient, although the current routine is a follow-up of 2 years. Because of a benign course in 85% of patients with NSP, a repeated invasive procedure after thoracoscopy is only indicated in a limited group of patients. The most important indications for a repeated pleural biopsy are persistent chest pain, recurrent pleural effusion, radiologic findings suggestive for malignant pleural disease.

© 2018 John Wiley & Sons Ltd.

In plain English

In this narrative review, the authors examined research on non-specific pleuritis: pleuritis on thoracoscopic biopsy that cannot be attributed to a specific benign or malignant cause. Pooling 5 studies, they counted 469 such diagnoses among 2434 thoracoscopies (5-31%, mean 19.2%). Of these patients, 66 (14.2%) had malignant pleural disease, mostly mesothelioma, identified during follow-up of at least 21 months. One reviewed study found female gender a significant risk factor for later malignancy, which the authors said may relate to women's higher cumulative asbestos exposure in a specific rural region of Turkey. Another reviewed study considered later surgical biopsy warranted, after thoracoscopy made difficult by fibrin layers and adhesions, if there was asbestos contact history or a CT scan suggestive of mesothelioma. They concluded one year of follow-up is most likely sufficient, although the routine is 2 years. They concluded that repeat invasive procedures are indicated only in a limited group, mainly patients with persistent chest pain on the side of the effusion, recurrent effusion, or CT findings suggestive of malignant pleural disease. They noted this one-year limit needs confirmation in future studies.

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: narrative review of published literature on non-specific pleuritis, including diagnostic procedures and follow-up time
• Who was studied: Patients with exudative pleural effusion whose thoracoscopic pleural biopsies showed non-specific pleuritis (fibrinous pleuritis not attributable to a specific benign or malignant etiology). They were pooled from 5 published studies totalling 2434 thoracoscopies
• Exposure: Not an exposure study. Asbestos is mentioned in two places. In a reviewed Turkish study, it was offered as a possible explanation for female gender being a risk factor. In another reviewed study, a history of asbestos contacts was a reason for surgical biopsy in cases where thoracoscopy had been difficult because of fibrin layers and adhesions
• Main results:
  • Across the 5 pooled studies, 469 of 2434 thoracoscopies resulted in a diagnosis of non-specific pleuritis (range 5-31%, mean 19.2%)
  • Among the 469 patients with non-specific pleuritis, 66 (14.2%) were found to have malignant pleural disease, mostly mesothelioma, during follow-up of at least 21 months
  • In the reviewed Metintas study, a multivariate analysis found three significant risk factors for an eventual malignant diagnosis: CT findings of malignant involvement, thoracic pain and female gender
  • In the reviewed Metintas study of 101 cases of non-specific pleuritis, the false-negative rate for mesothelioma was 16.3%
  • In the reviewed Janssen study, 7 of 10 false-negative mesothelioma cases had a thoracoscopy made difficult by fibrin layers and adhesions. In those cases, a later surgical biopsy was found warranted if there was a history of asbestos contacts or a CT scan suggestive of mesothelioma
  • The authors listed three main indications for a repeated (surgical) intervention: persistent chest pain on the side of the effusion, recurrence of pleural effusion, and CT scan findings suggestive of malignant pleural disease
• The authors' conclusion: The authors concluded that a follow-up of one year after thoracoscopy is most likely sufficient, although the current routine is 2 years. They also concluded that a repeated invasive procedure is indicated only in a limited group of patients
• Limitations the authors state:
  • The authors stated that the safety of limiting follow-up to one year has to be confirmed in future studies

Topics

Medical terms in this study, explained in our Lexicon: Etiology, Thoracoscopy, Mesothelioma, Pleural Biopsy, Pleural Effusion.

Related studies

• Outcome of patients diagnosed with fibrinous pleuritis after medical thoracoscopy — M. Metintas, G. Ak, et al. (2012)
• Outcome of patients with nonspecific pleuritis/fibrosis on thoracoscopic pleural biopsies — H.E. Davies, J.E. Nicholson, et al. (2010)
• Outcome of patients with nonspecific pleuritis at thoracoscopy — J.M. Wrightson, H.E. Davies (2011)
• GATA3 is a useful immunohistochemical marker for distinguishing sarcomatoid malignant mesothelioma from lung sarcomatoid carcinoma and organizing pleuritis — Z.H. Piao, X.C. Zhou, et al. (2021)
• Diagnostic accuracy and safety of semirigid thoracoscopy in exudative pleural effusions in Denmark — F. Willendrup, U. Bodtger, et al. (2014)
• Chronic follicular pleuritis: a B cell-rich form of nonspecific pleuritis/fibrosis — S.A. Yousem (2019)

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