The quality and diagnostic outcome of postbronchoscopic sputum.

In patients with a malignant lung process (146 patients with primary lung cancer and 21 patients with a metastatic lung malignancy), the quality and the percentage of true-positive diagnoses of sputum produced directly after bronchoscopy were evaluated. The quality of prebronchoscopic and postbronchoscopic sputum samples differed significantly, the former being of better quality for cytologic diagnosis. When calculated for the whole group, the quality of postbronchoscopy sputum was not related to any specific anamnestic or clinical patient data. Overall, there was no statistically significant difference between the percentages of true-positive diagnoses in prebronchoscopic and postbronchoscopic sputum specimens. However, the percentage of true-positive diagnoses was significantly higher in postbronchoscopic sputum in comparison with the results of sputum cytology prior to bronchoscopy when the results were calculated separately for patients with low forced expiratory volume values (less than 50% of the vital capacity) or for patients without a history of previous sputum production. In patients who produced bloody sputum, the percentage of true-positive diagnoses in prebronchoscopic sputum was significantly higher than in postbronchoscopic sputum.