Assessment of Diagnostic Accuracy of Bronchoalveolar Lavage Cytology in the Diagnosis of Lung Tumors and Contribution to the Classification of Non-Small Cell Lung Cancer Entities: A Retrospective Clinocopathological Study

Background: Due to new therapeutic options in thoracic oncology, the pathological diagnosis of bronchial carcinoma has become more challenging. The majority of bronchial cancer is diagnosed from small biopsy specimens and the diagnosis often based on cytological methods. Aims: In this study, we reevaluated cytologic specimens in order to determine the diagnostic reliability of pulmonary cytopathologic techniques performed in our department. Material and methods: In our center bronchial lavage/bronchoalveolar lavage (BL/BAL) specimens are obtained both before and after forceps biopsy (FB) and subsequently processed. Retrospective data from a period of 60 months were retrieved from the institutional files. Sensitivity, specificity, as well as accuracy of cytological tumor typing were determined using histopathology of FB as gold standard. Also, the diagnostic yield of BL/BAL before and after FB was determined. Results: 678 cases were retrieved from the institutional files. The sensitivity and specificity of cytology were 83.0% and 83.4%, respectively. By FB in 3.9% of cytologically diagnosed non-small cell lung carcinomas (NSCLC) a histological assignment to a NSCLC entity was not possible. Conclusions: Cytology is a reliable diagnostic tool in the diagnosis of lung malignancies. High diagnostic accuracy is achieved by a combination of BL/BAL before and after FB. The diagnostic yield of BL/BAL after FB was significantly higher than BL/BAL before FB. Subsequent tumor typing of cytologically diagnosed NSCLC was feasible in more than 95% of cases.