Finger clubbing in malignant mesothelioma and benign asbestos pleural disease

Our plain-English summary of Finger clubbing in malignant mesothelioma and benign asbestos pleural disease, by C. McGavin, P. Hughes (Respiratory Medicine, 1998).

The study

• Authors: C. McGavin, P. Hughes
• Journal: Respiratory Medicine
• Published: 1998;92(4):691-2
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

The authors asked whether malignant mesothelioma is itself associated with finger clubbing, or whether clubbing reported in mesothelioma might instead reflect underlying asbestosis. They compared how often finger clubbing occurred in asbestos workers with mesothelioma and in those with benign pleural disease. The subjects were 731 men with documented asbestos exposure, mainly from the Devonport naval base, seen at the Plymouth Chest Clinic in the U.K. Of these, 77 had mesothelioma, 108 had diffuse pleural fibrosis (DPF) with or without plaque, and 546 had pleural plaque alone. Mesothelioma was supported by histological or cytological evidence, and benign pleural disease was diagnosed on plain chest radiograph. Men with bronchial carcinoma were not included, and men considered to have asbestosis were excluded. A single observer, who was not blind to the diagnosis, examined all the men and recorded clubbing when there was abnormal fluctuation between the nail and its bed. Clubbing was found in 30% of the men with mesothelioma (23 of 77) and 14% of those with benign pleural disease (17% DPF, 12% plaque). The difference between mesothelioma and benign disease was highly significant (chi-squared = 16.0, P<0.0001). There was no significant difference between DPF and plaque. The authors concluded that these findings justified including malignant pleural mesothelioma as a cause of finger clubbing. They said that clubbing in an asbestos worker with an abnormal chest X-ray should alert the clinician to possible mesothelioma.

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 short report from the Plymouth Chest Clinic in the U.K. examined whether finger clubbing was more common in men with malignant mesothelioma than in men with benign asbestos-related pleural disease. The authors studied 731 men with documented asbestos exposure, mainly from the Devonport naval base: 77 with mesothelioma, 108 with diffuse pleural fibrosis and 546 with pleural plaque alone. Men considered to have asbestosis were excluded, and none of the men had bronchial carcinoma. One examiner, who knew each man's diagnosis, counted clubbing as present when the nail moved abnormally on its bed. Clubbing was found in 23 of 77 men with mesothelioma (30%), compared with 14% of men with benign pleural disease (17% with diffuse pleural fibrosis, 12% with plaque). The authors reported this difference as highly significant. They found no significant difference between the two benign groups. The authors concluded that the findings justify listing malignant pleural mesothelioma as a cause of finger clubbing. They noted possible observer error and bias, that not all clinicians accept this sign of clubbing, and that asbestosis cannot be excluded without histology.

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: Short report comparing how often finger clubbing was found on examination in asbestos-exposed men with mesothelioma versus benign pleural disease
• Who was studied: 731 men with documented asbestos exposure, mainly from the Devonport naval base, seen at Plymouth Chest Clinic, U.K. There were 77 with malignant mesothelioma, 108 with diffuse pleural fibrosis (with or without plaque) and 546 with pleural plaque alone. Men considered to have asbestosis were excluded, and no patient had bronchial carcinoma. Mesothelioma cases were seen clinically or for medicolegal reports. Benign cases were referred for medicolegal assessment.
• Exposure: Documented asbestos exposure, mainly from the Devonport naval base. Fiber types and doses are not given.
• Main results:
  • Finger clubbing, assessed as abnormal fluctuation of the nail bed, was present in 23 of 77 men with mesothelioma (30%). It was present in 14% of men with benign pleural disease: 18 of 108 with diffuse pleural fibrosis (17%) and 66 of 546 with pleural plaque (12%).
  • The difference in clubbing between mesothelioma and benign pleural disease was reported as highly significant (chi-square 16.0, P less than 0.0001).
  • There was no significant difference in the frequency of clubbing between men with diffuse pleural fibrosis and men with pleural plaque.
• The authors' conclusion: The authors concluded that the significantly higher incidence of clubbing in men with malignant rather than benign pleural disease justifies including malignant pleural mesothelioma as a cause of finger clubbing. They said the clinical value of this observation on its own is questionable. In their view, clubbing in an asbestos worker with an abnormal chest X-ray should alert the clinician to possible mesothelioma, rather than the clubbing simply being put down to asbestosis.
• Limitations the authors state:
  • A single observer, who was not blind to the diagnosis, examined all men. The authors accept that intraobserver error and bias may have occurred.
  • Not all clinicians may accept nail bed fluctuation as a reliable indicator of clubbing. The authors think its use presumably explains the relatively high rates in both groups.
  • Asbestosis cannot be excluded without histology. The authors judged that asbestos exposure seemed comparable in the benign and malignant groups.

Topics

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

Medical terms in this study, explained in our Lexicon: Clubbing, Mesothelioma, Asbestos-Related Pleural Disease, Asbestos Exposure, Fibrosis, Pleural Plaques, Chest X-Ray, Carcinoma.

Related studies

• Hypertrophic osteoarthropathy in childhood malignancy — C.R. Staalman, U. Umans (1993)
• Secondary hypertrophic osteoarthropathy caused by non-pleural or pulmonary tumors — H.J. Meyer, L. Leifels, et al. (2017)
• A retrospective study of chest pain in benign asbestos pleural disease — R.K. Allen, T. Cramond, et al. (2011)
• High-resolution CT of benign asbestos-related diseases: clinical and radiographic correlation — D.R. Aberle, G. Gamsu, et al. (1988)
• Clinical value of fluorodeoxyglucose-positron emission tomography/computed tomography in differentiation of malignant mesothelioma from asbestos-related benign pleural disease: an observational pilot study — H. Yildirim, M. Metintas, et al. (2009)
• Asbestos-related benign pleural disease — C. Peacock, S.J. Copley, et al. (2000)

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