Background: Pleuroscopy (medical thoracoscopy) is a minimally invasive procedure to
inspect and perform a biopsy of the pleural space as well as to perform therapeutic interventions;
pleural fluid drainage and pleurodesis.
Materials and Methods: In a retrospective study in Kasra Hospital, Tehran,Iran, the patients with
exudative pleural effusion of unknown etiology who underwent pleuroscopy, were evaluated. These
patients had negative smears and cultures for infective agents. Also, the cytological review was
negative for malignancy.
Results: 62 patients had undergone pleuroscopy, of which 29 (46.7) were men. After the final evaluation,
47 patients (75.8%) had a definite pathologic diagnosis, of which 39 patients (82.9%) had
cancer. Through these 39 cases, 18 cases (46.1%) had a history of the previously confirmed cancer,
in which pleural pathology was consistent with the initial diagnosis. In 21 cases (53.9%), metastatic
cancers were detected without a previous history. From a total of 47 cases with definite pathologic
diagnosis, 8 cases (17%) had histopathologic evidence of granulomatous lesions consistent with
tuberculosis, and 15 patients (24%) showed non-specific inflammatory lesions. There was no morbidity
and mortality among these patients.
Discussion: Considering that pleuroscopy is a safe procedure with high diagnostic accuracy, malignancy
is the most common finding in the exudative pleural effusion of unknown etiology, which increases
the importance of this procedure in these cases to prevent wasting time and smear-negative