Clinical impact of EUS-FNA of mediastinal lymph nodes in patients with known or suspected lung cancer or mediastinal lymph nodes of unknown etiology

Introduction: Endoscopic ultrasound guided fine needle aspiration (EUS-FNA) of mediastinal lymph nodes (LNs) has emerged as a valuable minimally invasive tool for staging. The objective of this study was to determine the accuracy of EUS-FNA of mediastinal LNs in patients with known or suspected non-small cell lung cancer (NSCLC) or with mediastinal LNs of unknown etiology and review its clinical impact. methods: A review was performed on 107 consecutive patients. If malignant cells were identified by EUS-FNA, the result was accepted as a true positive. When cytology was non-malignant, results were compared with the final surgical pathology. Results: Of 79 patients with known or suspected lung cancer who had mediastinal LNs, 69 patients underwent EUS-FNA. Thirty-two received a definitive diagnosis with EUS-FNA and did not undergo further workup, while 37 patients had benign (33) or nondiagnostic FNAs (4); 26 patients further underwent surgical staging. Sensitivity, specificity, and accuracy for EUS-FNA of mediastinal LNs in patients with known or suspected lung cancer was 82.35%, 100%, and 90% respectively. The negative predictive value was 80% and the positive predictive value was 100%. There were 20 patients with suspicious mediastinal LNs of uncertain etiology, with a definitive diagnosis being made using EGD/EUS-FNA in 95%. Conclusion: Our data supports the use of EUS-FNA in the work-up of enlarged mediastinal LNs on cross sectional imaging, thus avoiding more invasive mediastinal sampling procedures and potentially futile surgery.