Utility of endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis of mediastinal masses of unknown etiology.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been reported to be useful for lymph node staging in lung cancer. The role of EBUS-TBNA in the diagnosis of mediastinal masses of unknown etiology has not been described. The purpose of the current study was to investigate the clinical utility of EBUS-TBNA in the diagnosis of mediastinal masses of unknown etiology.

METHODS: Retrospective chart review of our EBUS-TBNA database between 2002 and 2007 was performed. Mediastinal masses of unknown origin in the absence of known pulmonary malignancy were included in the study. Final diagnoses were determined by EBUS-TBNA, surgery and (or) clinical follow-up. The EBUS-TBNA results were classified into two categories: (1) malignant mediastinal and (2) benign mediastinal.

RESULTS: A total of 140 patients with mediastinal masses of unknown origin without the presence of lung cancer or other pulmonary malignancy were identified. Final diagnosis was available in all patients by means of EBUS-TBNA, surgery, mediastinoscopy, or other diagnostic or long-term follow up. The final diagnoses were 40 malignant mediastinal and 100 benign mediastinal. The EBUS-TBNA was diagnostic in 131 of 140 patients (93.6%) for all disease categories (malignant 87.5%, benign 96.0%). The EBUS-TBNA was successful in directing subsequent workup and (or) therapy in 94 of 140 patients (67.1%). The EBUS-TBNA was uneventful and there were no complications.

CONCLUSIONS: Endobronchial ultrasound guided transbronchial needle aspiration is a safe and minimally invasive approach for sampling of mediastinal tissues. It should be considered for evaluation of mediastinal masses of unknown origin early in the diagnoses process. It spares more invasive procedures for tissue sampling of the mediastinum.