TOPIC: Procedures TYPE: Medical Student/Resident Case Reports INTRODUCTION: Endobronchial Ultrasound (EBUS) is a state-of-the-art diagnostic tool for diagnosing and staging lung cancer and can recognize several structures of the mediastinum; lymph nodes, tumors, vessels, pericardium, and the heart. We herein report a case of an incidental de-novo finding of pericardial effusion seen during the EBUS. CASE PRESENTATION: A 55 year old male with a history of tobacco abuse presented to the clinic with worsening dyspnea, fatigue, cough, and weight loss, and a contrast-enhanced CT scan of the chest showed right lower lobe lung mass with enlarged mediastinal and hilar nodes. Pulmonary service was consulted, and the patient underwent a successful EBUS bronchoscopy with a fine need aspiration of the enlarged lymph nodes. EBUS imaging from the sub-carinal region through the anterior wall of the left lower lobe bronchus showed pericardial effusion and, the pericardium was identified above the left atrium. The patient underwent an urgent echocardiogram confirming pericardial effusion and pericardiocentesis drained 1200 ml fluid later proved to be metastatic adenocarcinoma of lung origin. DISCUSSION: EBUS is increasingly used to evaluate mediastinal lesions, diagnose and staging malignancy. Pericardiocentesis under echocardiographicGuidance is considered the procedure of choice for the evacuation of pericardial effusions. Given the advantage of visualizing pericardium and heart during the EBUS, multiple reports have documented aspiration of pericardial effusion through a regular EBUS-TBNA needle. CONCLUSIONS: We here report a rare case of incidental pericardial effusion seen during the EBUS and highlight the possibility of detecting pericardial effusions early as several mediastinum structures: lymph nodes, tumors, vessels, pericardium, and the heart are visualized during the EBUS. Therefore, physicians must be aware of the alternative use of EBUS as a new diagnostic approach in the early detection of pericardial effusions, allowing for early initiation of therapy in an otherwise potentially life-threatening condition. REFERENCE #1: (EBUS) Application for Benign and Malignant Pericardial Effusion (PE) Aspiration: Transbronchial Pericardial Effusion Aspiration (TPEA) with a Regular EBUS Transbronchial (TBNA) Needle under Apneic Nasal Jet-Catheter Ventilation.” J Biomed 1 (2016): 9-25. REFERENCE #2: Sharma, Rahul K., Arjun Khanna, and Deepak Talwar. "Endobronchial Ultrasound: A New Technique of Pericardiocentesis in Posterior Loculated Pericardial Effusion.” Chest 150.5 (2016): e121-e123. REFERENCE #3: Gella, Vishwanath, Snigdha Ghana, and Upendra Srinivas. "Concurrent diagnostic pericardiocentesis and subcarinal mediastinal lymph node aspiration by EBUS TBNA.” (2015). DISCLOSURES: No relevant relationships by Venkatkiran Kanchustambham, source=Web Response No relevant relationships by Swetha Saladi, source=Web Response No relevant relationships by Vinita Vaidya, source=Web Response