[Thoracoscopy--the method of choice in the determination of a malignancy as the cause of pleural effusion of unknown etiology].

UNLABELLED: After complete pulmological investigation remains about 20% of all the pleural effusions without etiological diagnosis designated as unexplained pleural effusions. Thoracoscopy enables further investigation with the final aim--establishing of the etiological cause of the unexplained pleural effusions. Recently numerous studies demonstrated that the malignancy is the most frequent cause of this aforementioned pleural effusions. OBJECTIVE: Descriptive-analytic appraisal of validity of thoracoscopy in establishing of malignancy as a cause of idiopathic pleural effusions. TASKS: To establish if the malignancy is the most frequent cause of unexplained pleural effusions, to establish diagnostic-thoracoscopic sensitivity and specificity for malignant disease as cause of pleural effusions and to establish positive and negative predictive value of thoracoscopy for malignancy. PATIENTS AND METHODS: In the period between 06.11.1984 and 01.02.2002, included in this investigation were all patients with pleural effusions of unknown origin who were referred to the Clinic for Thoracic Surgery--UCC Sarajevo, for thoracoscopy after less invasive means of diagnosis had failed. Investigation had clinical-manipulative, descriptive-analytic and retrospective-prospective design. RESULTS: There were 74 patients with the pleural effusions of unknown origin. The malignancy was found in 47.3% (35/74) patients. Diagnostic sensitivity of the method for malignancy was 89.7% and the specificity 100.0%. The positive predictive value of the thoracoscopy for malignancy was 100.0% and negative predictive value 89.7%. CONCLUSIONS: The malignancy was the most frequent cause of idiopathic pleural effusions. Thoracoscopy has high specificity and sensitivity in regard to discovering of malignancy as a cause of idiopathic pleural effusions. Undiagnosed malignancy by thoracoscopy excludes malignancy as a cause of pleural effusion with high security.