A single EBUS-TBNA procedure can support a large panel of immunohistochemical stains, specific diagnostic subtyping, and multiple gene analyses in the majority of non-small cell lung cancer cases.

Targeted therapies for pulmonary adenocarcinoma (ACA) necessitate specific subtyping and molecular testing of non-small cell lung carcinomas (NSCLC). However, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has decreased the tissue available for these assessments. While EBUS-TBNA specimens have previously been reported to successfully subtype NSCLC, allow immunohistochemistry (IHC), and support molecular diagnostics, no studies have documented the extent to which all objectives are possible in a single sample. Of 107 consecutive EBUS-TBNA specimens that were eligible for molecular testing, 98.8% had enough tissue for IHC, 80.2% received a definitive subtype, and 71.0% had both sufficient tissue to attempt molecular testing and technical success on multigene next-generation sequencing and ALK fluorescence in situ hybridization assays. Both subtyping and molecular diagnostics were possible in 57.9% of patients. The mean number of immunostains performed did not differ between patients with or without successful molecular testing (4.4 versus 4.6, P = .88). Only 40% of patients with insufficient tissue underwent repeat sampling. These findings indicate that a majority of EBUS-TBNA specimens provide sufficient tissue for subtyping pulmonary NSCLC, performing IHC, and completing multiple gene analyses. Although priorities must be assessed for each case individually, performance of IHC does not detract from completion of molecular diagnostics in general. Because most patients never undergo repeat sampling, the tissue yield of EBUS-TBNA should be improved to maximize evaluation for targeted therapies.