Evolution of idiopathic pleural effusion: a prospective, long-term follow-up study

Our plain-English summary of Evolution of idiopathic pleural effusion: a prospective, long-term follow-up study, by J.S. Ferrer, X.G. Muñoz, R.M. Orriols, et al (Chest, 1996).

The study

• Authors: J.S. Ferrer, X.G. Muñoz, R.M. Orriols, R.W. Light, F.B. Morell
• Journal: Chest
• Published: 1996;109(6):1508-13
• Cited by: 80 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Unlabelled: The management of idiopathic pleural effusion remains controversial. Because the long-term evolution of this entity is not well known, two different approaches, aggressive and conservative, have been proposed. We conducted a 10-year study of the evolution of idiopathic pleural effusion.

Methods: Between 1984 and 1994, we prospectively studied 40 consecutive patients (30 men and 10 women; mean [+/- SD] age, 53.8 +/- 19.4 years) with exudative pleural effusion undiagnosed after exhaustive evaluation. The pleural fluid adenosine deaminase level was below 43 IU/L in all; periodic chest radiographs and clinical evaluation were carried out in all patients for a mean of 62 months (range, 36 to 108 months). Further diagnostic procedures were performed whenever the effusion recurred or when indicated by the clinical picture.

Results: Effusions resolved in a mean time of 5.6 months (range, 7 days to 48 months). Five patients (12.5%) had one or more relapses of their pleural effusion, and in a further 5 (12.5%), the effusion persisted unchanged for more than 1 month. In 32 cases (80%), no potential cause of the effusion was detected. The diagnoses in the remaining eight cases were asbestos pleural effusion in three, pulmonary adenocarcinoma in one, mesothelioma in one, congestive heart failure in one, liver cirrhosis in one, and rheumatoid arthritis in one. Tuberculosis was not detected in any of the cases, although 19 patients initially had positive tuberculin tests.

Conclusions: Most idiopathic pleural effusions follow a benign course. Our results support conservative treatment of patients with idiopathic pleural effusion. Antituberculous treatment does not appear to he warranted, regardless of tuberculin test results, if the pleural fluid adenosine deaminase level is not elevated.

In plain English

This prospective study in Barcelona followed 40 consecutive patients whose exudative pleural effusion (fluid around the lung) remained undiagnosed after extensive testing. Patients enrolled from 1984 to 1991 were followed until March 1994, for a mean of 62 months. In the 38 patients who did not have talc pleurodesis or decortication during the first admission, effusions resolved in a mean of 5.6 months (median 1.7 months; range 7 days to 48 months). Five (12.5%) had relapses, and five others did not improve in the first month. In 32 patients (80%) no possible cause was found. Three patients later recalled asbestos contact: two years making brake linings at age 17, sporadic exposure as a linotypist, and an asbestos board in a vacation-house kitchen. None developed further disease over 3 years, and the authors suggested these may have been benign asbestos-induced effusions. Mesothelioma was diagnosed in one patient and lung adenocarcinoma in another. No patient developed tuberculosis, although 19 had positive tuberculin tests. The authors concluded that most such effusions follow a benign course, supporting a conservative approach.

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: Prospective follow-up study of consecutive patients with idiopathic (undiagnosed) pleural effusion
• Who was studied: 40 consecutive patients (30 men, 10 women; mean age 53.8 years) with exudative pleural effusion that remained undiagnosed after exhaustive evaluation, at a hospital department in Barcelona, Spain. They were drawn from 394 patients with pleural effusion admitted between January 1984 and March 1991, of whom 53 had idiopathic effusions. 13 of these 53 were excluded: 4 because their history suggested a cause, and 9 who did not attend follow-up. Follow-up ran until March 1994.
• Exposure: Not an exposure study. Patients were questioned repeatedly about past asbestos exposure. During follow-up, three recalled previous contact with asbestos: brake lining manufacture for 2 years at age 17, sporadic exposure as a linotypist 25 years earlier, and an asbestos board in the kitchen of a vacation house used every summer for 47 years.
• Main results:
  • In the 38 patients remaining after one had talc pleurodesis and one had pleural decortication during the initial hospitalization, the mean time to resolution of the effusion was 5.6 months (range 7 days to 48 months; median 1.7 months).
  • Five of the 40 patients (12.5%) had one or more relapses. In a further 5 (12.5%), the effusion persisted unchanged for more than 1 month.
  • In 32 of the 40 cases (80%), no potential cause of the effusion was detected.
  • In the remaining eight cases the diagnoses were asbestos pleural effusion in three, pulmonary adenocarcinoma in one, mesothelioma in one, congestive heart failure in one, liver cirrhosis in one, and rheumatoid arthritis in one.
  • None of the three patients with recalled asbestos exposure developed further disease in 3 follow-up years. The authors suggested their diagnosis may have been a benign asbestos-induced effusion.
  • Neoplasms were detected in 2 of the 40 patients (5%). Mesothelioma was diagnosed 4 years after the effusion and pulmonary adenocarcinoma 2 years after it.
  • Tuberculosis was not detected in any of the 40 patients, although 19 initially had positive tuberculin tests.
  • Nine of the 40 patients (22%) died during follow-up.
  • Among the patients excluded from the analysis, two had a history of asbestos exposure. One was diagnosed with a benign asbestos pleural effusion, and mesothelioma was detected in the other after 3 months.
• The authors' conclusion: The authors concluded that most idiopathic pleural effusions follow a benign course and that the approach should be conservative. They also concluded that antituberculous treatment does not appear warranted, even with a positive tuberculin test, if the pleural fluid adenosine deaminase level is not elevated. They recommended follow-up to ensure resolution.

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: Idiopathic, Pleural Effusion, Chest X-Ray, Adenocarcinoma, Mesothelioma.

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