Evaluation of the diagnostic utility of endobronchial ultrasound-guided transbronchial needle aspiration for metastatic mediastinal tumors

Background and Objectives: The mediastinum is a relatively uncommon site of distant metastases, which typically appear as peripheral lung nodules. We chose to assess the utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for the diagnosis of distant metastases to the mediastinum. Materials and Methods: Over the period 2008-2013, a total of 446 patients with concurrent or previously diagnosed and treated extrathoracic malignancies were evaluated. Results: Surgical treatment was carried out in 414 patients (156 women and 237 men aged 26-68 years, mean age of 56.5 years) presenting with distant metastases to the lungs: Thoracoscopic wedge resection was completed in 393 patients and lobectomy and segmentectomy were performed in 7 and 14 patients, respectively. The median time from primary tumor resection was 6.5 years (range: 4.5 months to 17 years). Thirty-two of these patients underwent EBUS-TBNA for mediastinal manifestation of the underlying disease. EBUS-TBNA specimens were aspirated from the subcarinal or right paratracheal lymph node stations in 26 (81%) patients and from the hilar lymph nodes in 6 (18.8%) patients only. Metastases to lymph nodes were confirmed in 14 of these patients (43.8%). Primary lung cancer was diagnosed in seven patients. Mediastinoscopy was performed in two patients to reveal either lymph node metastasis or sarcoidosis. Thoracotomy for pulmonary metastases resection and mediastinal lymph node biopsy was performed in nine patients. Lymph node metastasis was confirmed in five patients (15.6%). The diagnostic efficacy, sensitivity, specificity, and negative predictive value (NPV) of EBUS-TBNA were 78.8%, 93.3%, 100%, and 87.5%, respectively. Conclusion: EBUS-TBNA is a valuable diagnostic tool in a selected group of patients with secondary tumors in the mediastinum and lungs.