Abstract
Diagnosis of pleural effusion includes the demonstration of the pleural effusion, the differentiation of exudates from transudates and the evaluation of the etiology. If the diagnosis can not be reached, closed pleural biopsy, thoracoscopy and thoracotomy may be required besides clinical findings, imaging techniques, thoracentesis and the cytologic, chemical, bacteriologic analysis of the fluid. Bronchoscopy and similar approaches may also help diagnosis in some cases. In this review, the value and limitations of such approaches concerned in the diagnosis of pleural effusions are discussed in the light of recent literature.