In spite of the progress in the diagnostic methods, about 20% of the pleural effusions may remain without a proper diagnosis after the use of conventional exams. In order to determine the origin of these effusions, alternative methods and invasive procedures shall be used aiming to determine the etiology of the undiagnosed pleural effusions and institute the most appropriate therapeutics.
Pleural effusion; Pleural effusion; Diagnosis, differential; Sensitivity and specificity