Diagnostic yield of broncho-alveolar lavage fluid and postbronchoscopic sputum cytology in endoscopically non-visible lung cancers.

Diagnostic yield of broncho-alveolar lavage (BAL) fluid and postbronchoscopic sputum (PBS) cytology is very high in endoscopically visible bronchogenic carcinoma, but they are also helpful in diagnosis of those lung cancers which are not visible bronchoscopically. Objective of this prospective study is to analyse the diagnostic yield of BAL fluid and PBS cytology in endoscopically non-visible lung cancer. Thirty patients with chest radiographic abnormality suspicious of lung cancer without endobronchial abnormality underwent BAL fluid and PBS cytology examination in the department of respiratory medicine of Calcutta National Medical College and Hospital over 1 year and 3 months. The final diagnosis was bronchogenic carcinoma in 21, tuberculoma/tuberculosis in 5, bacterial pneumonia in 3 and encysted empyema in 1. Among the 21 patients with bronchogenic carcinoma, BAL was positive for malignant cell in 13 patients (62%). The diagnostic yield of the BAL was influenced by size, location, radiographic pattern and cell type of the tumour. PBS cytology was positive in 3 patients (14%) only, all of which were positive with BAL fluid also. BAL fluid cytology proved to be a valuable diagnostic tool in diagnosis of endoscopically non-visible lung cancer. Size, location, radiographic pattern and cytological type of the lesions were important determinants of the diagnostic yield. PBS cytology provided no additional benefit.