Etiology of pleural effusions: analysis of more than 3,000 consecutive thoracenteses

Our plain-English summary of Etiology of pleural effusions: analysis of more than 3,000 consecutive thoracenteses, by J.M. Porcel, A. Esquerda, M. Vives, et al (Archivos de Bronconeumología, 2014).

The study

• Authors: J.M. Porcel, A. Esquerda, M. Vives, S. Bielsa
• Journal: Archivos de Bronconeumología
• Published: 2014;50(5):161-5
• Language: Spanish
• Cited by: 244 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: To investigate the etiology of pleural effusions (PE) in adults and the accuracy of pleural fluid (PF) cytology and cultures in malignant and infectious PE, respectively.

Patients And Methods: Retrospective analysis of all consecutive patients with PE undergoing diagnostic thoracentesis during the last 19 years in a university hospital.

Results: The leading causes of PE among the 3,077 patients were: cancer (27%), heart failure (21%), pneumonia (19%), tuberculosis (9%), abdominal surgery (4%), pericardial diseases (4%) and cirrhosis (3%). Tuberculosis was the most common etiology in patients <34 years of age (52%), whereas heart failure predominated in octogenarians (45%). The most common primary tumors in malignant PE were lung (37%) and breast (16%). The overall accuracy of PF cytology was 59%, although it was significantly lower in mesotheliomas (27%) and squamous cell lung cancer (25%). In infectious PE, only 30% of cultures yielded positive results, a percentage which increased two-fold (66%) in purulent fluids (empyemas). Viridans streptococci were the most commonly isolated pathogens (25.5%). The sensitivity of solid media cultures of PF for Mycobacterium tuberculosis was low (18.5%).

Conclusions: Three-quarters of patients with PE in whom a diagnostic thoracentesis was indicated had cancer, heart failure, pneumonia or tuberculosis. PF cytology and cultures give false negative results in a significant number of cases.

Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

In plain English

This retrospective study, from a university hospital in Lleida, Spain, covered 3,077 adults who had a diagnostic thoracentesis (fluid drawn from around the lung) for a pleural effusion between January 1994 and June 2013. The most common causes were cancer (27%), heart failure (21%), pneumonia (19%) and tuberculosis (9%). Tuberculosis caused 52% of effusions in patients under 34, and heart failure caused 45% in patients in their eighties. Of 840 cancer-related effusions, lung (37%) and breast (16%) were the most common primary tumors. Mesothelioma, a primary tumor of the pleura, accounted for 22 cases (3% of malignant effusions). Of these, 86% were men, and all were diagnosed by tissue examination. Fluid cytology detected 6 of the 22 (27%), significantly lower than in the other groups. Overall, cytology detected cancer in 491 of 831 patients (59%). The study did not examine asbestos exposure. The authors concluded that fluid cytology gives false negative results in at least 40% of patients whose effusion is caused by cancer. They noted that including only patients who had a diagnostic thoracentesis may leave some causes under-represented.

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 study of consecutive patients, using a database filled in prospectively since 1994
• Who was studied: 3,077 adults with pleural effusion who had a diagnostic thoracentesis at Hospital Universitario Arnau de Vilanova, Lleida, Spain, from January 1994 to June 2013. Median age was 69; 1,826 (59%) were men. 206 patients without a definitive diagnosis or with insufficient studies were excluded.
• Exposure: Not an exposure study. The study classified the causes of pleural effusion and did not assess asbestos or any other exposure.
• Main results:
  • Among all 3,077 patients, the leading causes of effusion were cancer (27%), heart failure (21%), pneumonia (19%) and tuberculosis (9%).
  • In 293 patients under 34, effusions were mainly due to tuberculosis (153; 52%) and pneumonia (75; 26%).
  • In 760 octogenarian patients, the most common causes were heart failure (344; 45%) and cancer (181; 24%).
  • Among the 840 malignant effusions, the primary tumor was lung in 37% and breast in 16%.
  • Mesothelioma (primary tumor of the pleura) was uncommon in this area: 22 cases, 3% of all malignant effusions.
  • Mesotheliomas occurred mainly in men (19 of 22, 86%).
  • All mesotheliomas were diagnosed by histological (tissue) criteria.
  • Pleural fluid cytology detected mesothelioma in 6 of 22 cases (27%), significantly lower than in the other groups (p = 0.002). It detected squamous cell lung cancer in 17 of 67 cases (25%).
  • Counting all cytology samples taken, cytology identified malignancy in 491 of 831 patients with malignant effusion (59%).
  • Pleural fluid cultures were positive in 108 of 163 empyemas (66%), 47 of 208 complicated parapneumonic effusions (23%) and 14 of 191 uncomplicated parapneumonic effusions (7%).
  • Solid-medium culture grew Mycobacterium tuberculosis in 44 of 237 pleural fluid samples (18.5%).
• The authors' conclusion: The authors concluded that three-quarters of effusions needing diagnostic thoracentesis were due to cancer, heart failure, pneumonia or tuberculosis. They added that pleural fluid cytology is a simple test for diagnosing malignancy but gives false negative results in at least 40% of cases, meaning cases of malignant effusion (cytology detected 491 of 831).
• Limitations the authors state:
  • Only patients who underwent a diagnostic thoracentesis were included.
  • As a result, some causes, such as heart failure and pulmonary embolism, may be under-represented.
  • The hospital had no cardiac or thoracic surgery, which explains the small number of effusions related to those procedures.

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: Etiology, Pleural Effusion, Cytology, Thoracentesis, Pericardial, Mesothelioma, Squamous Cell, Lung Cancer.

Related studies

• Palliative and therapeutic activity of IL-2 immunotherapy in unresectable malignant pleural mesothelioma with pleural effusion: Results of a phase II study on 31 consecutive patients — B. Castagneto, S. Zai, et al. (2001)
• Diagnostic accuracy and safety of semirigid thoracoscopy in exudative pleural effusions in Denmark — F. Willendrup, U. Bodtger, et al. (2014)
• Evolution of idiopathic pleural effusion: a prospective, long-term follow-up study — J.S. Ferrer, X.G. Muñoz, et al. (1996)
• Diagnostic value of soluble mesothelin-related peptides in pleural effusion for malignant pleural mesothelioma: An updated meta-analysis — R. Gao, F. Wang, et al. (2019)
• Expression Profiles of Cytokine mRNAs in the Pleural Fluid Reveal Differences Among Tuberculosis, Malignancies, and Pneumonia-Exudative Pleural Effusions — D.L. Espósito, V.R. Bollela, et al. (2015)
• Flow cytometric measurement of cellular FLICE-inhibitory protein (c-FLIP) in ovarian carcinoma effusions — H.P. Dong, A.K. Ree Rosnes, et al. (2011)

Browse more research in Archivos de Bronconeumología, or return to medical research.