Endobronchial Ultrasound-guided Transbronchial Needle Aspiration 
in the Diagnosis of Intrathoracic Metastasis from Extrapulmonary Malignancy

Background and objective Endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) has been widely applied in diagnosing mediastinal and hilar adenopathy. This study is further to evaluate value and safety of EBUS-TBNA in diagnosing intrathoracic metastasis from extrapulmonary malignancy. Methods Prospectively analysis of 41 patients suspected intrathoracic metastasis from previous diagnosed/concurrent extrapulmonary malignancies in Shanghai Chest Hospital, with radiologic findings showing mediastinal/hilar lymph node enlargement or intrapulmonary lesion requiring EBUS-TBNA examination for pathological diagnosis. Results 41 candidate patients enrolled, and 67 mediastinal/hilar lymph nodes and 5 intrapulmonary lesions were aspirated. 14 intrathoracic metastasis, 10 primary lung cancer, 9 reactive lymphadenitis, 4 sarcoid-like reactions, and 1 tuberculosis was diagnosed by EBUS-TBNA. Sensitivity and accuracy of EBUS-TBNA in diagnosing intrathoracic metastasis was 87.50% and 95.12%, respectively. Immunohistochemistry (IHC) was performed in 18 malignant tumors to obtain definite type or origin, twelve intrathoracic metastasis and 6 primary lung cancer were further confirmed. Conclusion EBUS-TBNA is a safe, effective method for the diagnosis of intrathoracic metastasis from extrapulmonary malignancy. IHC can provide additional evidence for distinguishing extrapulmonary malignancy from primary lung cancer