Efficacy of Endobronchial Ultrasound-Guided Transbronchial Needle Biopsy for the Diagnosis of Intrathoracic Lymph Node Metastases from Extrathoracic Malignancies

INTRODUCTION The thorax is an area in which distant metastases are frequently observed because it is located on the hematologic and lymphatic pathways (1). Various malignant neoplasms can metastasize to the lung (parenchymal or endobronchial), the hilar-mediastinal lymph nodes, pleura, pericardium, or to the chest wall. The lungs and mediastinum, especially, are the places where other malignancies often metastasize. Most commonly, breast, colon, and renal cancers metastasize to the lung (2, 3). However, they may not all be mediastinal lymph node metastases; simultaneously, it should also be considered that it could be granulomatous disease or primary lung cancer. The early detection of mediastinal metastases is important for the treatment and prognosis of the primary malignancy (4).