7246 Cardiac Paraganglioma: A Rare Entity

Abstract Disclosure: L. Javed: None. L. Jonea: None. Cardiac paragangliomas are an exceptionally uncommon subset of neuroendocrine neoplasms. We present a case of a patient presenting with this condition. 70-year-old woman with pertinent past medical history of chronic veinous insufficiency complicated by recurrent abscesses of her right leg since venaseal procedure. The patient had positive IgG lambda on immunofixation that raised concerns for MGUS. Therefore, a F-18 FDG PET-CT scan was performed for further evaluation. PET-CT revealed a hypermetabolic mass in the upper inner right thigh and the right atrium (SUV 17.6) raising concern for septic thrombi. She was admitted in the hospital for initiation of antibiotic therapy. Transesophageal echocardiogram (TEE) revealed a 4.5 cm x 4.0 cm mass in the right atrioventricular (AV) groove region, extending over the root of the main pulmonary artery. Following discharge, despite completing six weeks of IV antibiotic therapy a CT scan on a subsequent clinic visit revealed the same mass as seen on TEE. CT imaging raised suspicion of neuroendocrine tumor. This led to referral to the endocrinology department. Laboratory results showed elevated normetanephrine and dopamine levels increasing likelihood of paraganglioma. Lab Results: 24 hr urine normetaneprhine :7197(N ≤ 376 mcg), 24 hr urinary dopamine :879 (N ≤400 mcg), 24 urinary metanephrine: 84 (N ≤96 mcg) 3 (N ≤20 mcg). Her home systolic blood pressure readings varied between 120’s & 170’s. She was initiated on Prazosin 1 mg daily in addition to the existing antihypertensive medications of nebivilol, amlodipine & furosemide. Few months later, this patient successfully underwent cardiac mass resection. Histologic findings of the resected mass were consistent with paraganglioma. Post-surgery, anti-hypertensive medications were discontinued, and blood pressure normalized to systolic readings in the 90s to 120s and diastolic readings in the 60s to 80s. Repeat biochemical tests indicated a normalization of normetanephrine & dopamine levels, validating the success of the resection. This case features an extremely rare entity cardiac paraganglioma that had an atypical clinical manifestation of being asymptomatic. Timely diagnosis and appropriate management are crucial for patient outcomes. Surgical intervention, although fundamental, bears significant risks, necessitating meticulous preoperative management to mitigate potential complications. The medical approach focuses on averting perioperative complications such as hypertensive crisis, cardiac arrhythmias and myocardial infarction. This is achieved by administering alpha and beta adrenoceptor blockers for a minimum of two weeks before the scheduled surgery. Regular follow up is also essential due to the unpredictable malignant potential of these tumors. Presentation: 6/3/2024