A Descriptive Analysis of EUS-FNA for Mediastinal Lymphadenopathy: An Emphasis on Clinical Impact and False Negative Results

OBJECTIVES: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been shown to accurately diagnose mediastinal lymph node pathology. We investigated the clinical impact of EUS-FNA in the management of patients with mediastinal lymphadenopathy, and determined the nature and clinical consequences of false negative results. METHODS: We analyzed a cohort of patients who were found to have mediastinal lymph nodes by EUS and underwent FNA. The diagnostic standard included FNA cytology, histopathology, and clinical follow-up. RESULTS: Sixty EUS-FNAs of mediastinal lymph nodes were performed on 59 patients (mean age 61 years old, 74.5% men) over a 24-month period. Prior to EUS, 20 (34%) patients had known malignancy. The most frequent indication for EUS was failed diagnosis by bronchoscopy (54%). EUS-FNA of lymph nodes showed malignant cells in 38%. The diagnostic accuracy of EUS-FNA was 84%. Among the 47 patients who were available for follow-up, EUS-FNA provided new information by changing the clinical diagnosis, and subsequently changed the management in 18 (38%) patients. The false negative rate was 20% (95% exact CI, 8.4-31.6%). Two of the 7 false negative cases received empiric chemoradiation without tissue diagnosis, and 4 received palliative treatment for advanced malignancy. CONCLUSION: The most common indication for EUS-FNA of the mediastinum in our institution is nondiagnostic transbronchial FNA. EUS-FNA is a valuable diagnostic method for sampling mediastinal lymph nodes and affecting management. False negative results do not appear to delay appropriate treatment or adversely affect clinical outcome.