Transbronchial FNA is especially useful for the diagnosis of primary lung lesions lying beneath the bronchial surface and for staging lung cancer patients with mediastinal lymphadenopaty. The lesion is aspirated by a retractable needle (Wang needle) that is passed through a flexible catheter sent down the bronchoscope.
Complications of transbronchial FNA are rare, including endobronchial bleeding.
When used for sampling mediastinal lymph nodes, at least a moderate number of lymphocytes must be present to consider the specimen as adequate. When used with other bronchoscopic specimens, transbronchial FNA increases the diagnostic accuracy of primary lung neoplasms. The distinction of small cell from non-small cell lung cancer is also good.