Bronchoalveolar lavage in the assessment of primary and metastatic lung cancer.

Bronchoalveolar lavage (BAL) can provide diagnostic information in cases of primary and metastatic disease to the lung. Diagnostic material can be obtained in about 50% of primary lung cancers, with more accuracy in bronchoalveolar cell carcinoma and adenocarcinoma than in squamous cell carcinoma. The diagnostic yield for cytologic examination is comparable to that of other widely used endoscopic techniques such as transbronchial biopsy. Technical considerations for the performance of BAL for the diagnosis of cancer remain incompletely defined. These include: 1) methods to assure lavage of the appropriate segment, 2) the type of cytologic preparation and stain used, 3) conditions such as viral infections and anti-neoplastic chemotherapy, which can induce changes in airway epithelial cells very difficult to distinguish from malignancy, 4) the optimum technique for the performance of lavage. Lavage may be limited in staging patients with primary lung cancer, but may be useful in staging metastatic lung cancer. In selected clinical situations, BAL will be an important tool for the physician caring for patients in whom malignancy of the lung is suspected.