Pleuroscopy in 'Idiopathic' eosinophilic pleural effusions

Area of Science:

• Pulmonology
• Thoracic Medicine
• Diagnostic Procedures

Background:

• Idiopathic eosinophilic pleural effusions (IEPE) are diagnosed when no specific cause is found.
• Existing IEPE diagnostic criteria rely on clinical and thoracocentesis findings, lacking systematic pleuroscopy investigation.
• A standardized pleuroscopy approach with patient follow-up is needed for IEPE diagnosis and outcome assessment.

Purpose of the Study:

• To evaluate the clinical outcomes of patients diagnosed with IEPE using a systematic pleuroscopy approach.
• To establish the diagnostic value of pleuroscopy in cases of unexplained eosinophilic pleural effusions.

Main Methods:

• Retrospective analysis of 10 patients diagnosed with IEPE out of 175 undergoing pleuroscopy for undiagnosed pleural effusion.
• Systematic pleuroscopy with pleural biopsy of observed lesions.
• Clinical and imaging follow-up of all patients for a median of 60 months (range 24-102 months).

Main Results:

• IEPE was confirmed in 10 patients (median age 50.5 years).
• Pleural examination revealed thickening and plaques in 8 patients (histologically confirmed eosinophilic inflammation) and nodules in 2 (non-caseating granulomas).
• No specific etiology was identified in any patient; all had a benign, relapse-free course without specific treatment during follow-up.

Conclusions:

• Pleuroscopy is essential for diagnosing IEPE.
• Negative histology and prolonged follow-up indicate a benign clinical course for these effusions.
• The term 'indeterminate' may be more appropriate for these effusions given their benign nature.