Endobronchial ultrasound-guided transbronchial fine-needle aspiration of mediastinal lymph nodes: a clinical appraisal of diagnostic accuracy and molecular utility.

Endobronchial ultrasound-guided transbronchial fine-needle aspiration (EBUS-TBNA) is currently recommended as the technique of choice for mediastinal and hilar lymph node staging in lung cancer, when technically feasible. It is also widely employed in the diagnostic evaluation of mediastinal and hilar lymphadenopathies of uncertain origin. To evaluate the diagnostic performance of EBUS-TBNA for mediastinal and hilar lymphadenopathies and to assess the adequacy of obtained tissue for molecular and immunohistochemical testing. Procedures performed by a single experienced bronchoscopist were retrospectively reviewed at two institutions: the Research Hospital "Casa Sollievo della Sofferenza" (August 2017-August 2019) and the "Teresa Masselli Mascia" Hospital (May 2022-December 2023). Final diagnoses were based on cytopathological results and/or clinical follow-up. Among 104 patients, overall diagnostic accuracy was 95.2%, with a sensitivity of 94.1%, specificity of 100.0%, PPV of 100.0%, and NPV of 80.0%. EBUS-TBNA achieved 100% accuracy for staging or restaging known malignancies. Among patients with advanced NSCLC (stage IIIb-IV), 76.3% (29/38) had samples adequate for PD-L1 testing, and 86.2% of adenocarcinomas were suitable for ALK/ROS1 assessment. Diagnostic accuracy increased from 92.8% to 100% across centers, though not statistically significant. EBUS-TBNA provides high diagnostic accuracy and yields adequate material for molecular profiling, confirming its essential role in the diagnostic and staging pathways of thoracic malignancies.