A80-3-38 Discovery of a Uniquely Positioned, Intensely Fluorodeoxyglucose-avid Mediastinal Lymph Node in Non-small Cell Lung Cancer

Abstract Introduction Lung cancer is the third most common and deadliest cancer in the US. Staging reflects the greatest prognostic predictor in lung cancer, and mediastinal lymph node sampling allows for staging of tumors. Accurate staging is essential for determining prognosis and guiding treatment, yet this process can be complicated by the presence of metabolically active lesions in anatomically complex or inaccessible regions. This case details the identification of a mediastinal lymph node in the pericardiac region discovered in a 69-year-old male with non-small cell lung cancer (NSCLC). Case Report A 69-year-old male with a 50 pack-year smoking history presented to an internist after having not seen a physician for 13 years with concern of 50-pound weight loss in one year and cough. Computed tomography (CT) of the chest revealed a 9.4 x 6.5 cm left hilar mass. A positron emission testing (PET) scan was performed and additionally found a 2.64 x 1.99cm intensely Fluorodeoxyglucose (FDG) avid nodule with a standardized uptake value (SUV) of 13.9 located in the cardiac area of the mediastinum and inferior to the carina, wedged between the aorta and heart. Endobronchial ultrasound (EBUS) was utilized for obtaining biopsies for diagnosis and staging; the left hilar mass was confirmed to be squamous cell carcinoma (SCC), and the left and right paratracheal and subcarinal lymph nodes were negative for malignancy. Due to the unusual location of the aforementioned FDG-avid lymph node, interventional pulmonology was not able to obtain a sample from this nodule. The patient was diagnosed with stage IIIb (cT4, cN2a, cM0) SCC of the left upper lobe (LUL) and is undergoing treatment. Discussion This case underscores the diagnostic and management challenges associated with FDG-avid mediastinal lesions located adjacent to vital cardiac structures. There is little documented literature about a mediastinal nodule located in this anatomical location that is inaccessible to standard biopsy techniques. This highlights a significant knowledge gap regarding optimal diagnostic strategies and clinical management in such scenarios. Conclusion This case represents a rare presentation of lung SCC with an inaccessible pericardiac FDG-avid mediastinal nodule. It emphasizes the importance of individualized, multidisciplinary decision-making and the need for further reporting to guide future management when tissue diagnosis is unobtainable. Figure 1 (A) Contrast-enhanced CT chest demonstrating a pericardiac mediastinal nodule located inferior to the carina and wedged between the aorta and heart. (B) Corresponding PET-CT showing intense FDG uptake (SUV 13.9) within this nodule. This abstract is funded by: None