SAT314 Bilateral Sporadic Carotid Paraganglioma As A Rare Cause Of Syncope

Disclosure: A.G. Olafimihan: None. U.A. Ogar: None. I. Asemota: None. E. Krishnaraju: None. A. Okafor: None. Introduction: Carotid body tumors (CBT) are rare, mostly non-secretory skull-based neuroendocrine tumors originating from the parasympathetic ganglia. They are the most common (60%) paragangliomas of the head and neck. Bilaterality is seen in 5% of patients with sporadic CBT. CBT mainly presents as an asymptomatic neck mass. Seldomly, it compresses the carotid sinus, inducing bradycardia and hypotension, and presenting with recurrent syncope. Case presentation: A 70-year-old Eritrean woman visiting the US with a history of myasthenia gravis status post thymectomy on pyridostigmine presented following an episode of presyncope with five similar episodes in the past year. She described it as sudden onset lightheadedness that resolves with sitting and sometimes results in syncope. She had no palpitations, headaches, or sweating.Her admitting vital signs were significant for bradycardia (48bpm) with hypotension (112/54mmhg). A physical exam revealed mobile, mildly tender, palpable neck masses bilaterally, with reproducible worsening bradycardia on palpation of the masses. ECG was unremarkable except for sinus bradycardia. A CT angiogram head and neck with contrast showed multiple hyper-enhancing lesions (two on the right, one on the left; largest = 1.6 x 1.0 cm) at the junction of bilateral carotid bulbs suggestive of multiple paragangliomas. An MRI of the neck re-demonstrated these lesions with the classical ‘salt and pepper’ appearance. CT of the brain, chest, abdomen and pelvis were negative for metastatic lesions. Biochemical testing including plasma metanephrines, catecholamines and dopamine levels was normal, suggesting nonfunctional tumors. Genetic testing was negative for mutations associated with paragangliomas. She did not have more episodes during her three-day admission but remained bradycardic with uneventful telemetry. She was counseled to avoid sudden neck movement and neck pressure. She was discharged with multidisciplinary (endocrinology, neurology, vascular surgery, and ENT surgery) outpatient follow-up. Over the five months post-discharge, she had only two mild symptomatic episodes. Following multi-specialist deliberations at the tumor board, including a risk-benefit assessment of a surgical excision, and extensive discussions with our patient and her family, the decision to hold off surgery was made. Surgical intervention was associated with possible vagal nerve injury, and high aspiration risk given her comorbid myasthenia gravis. Her conservative management plan included a cardiology work-up for symptom-directed therapy with a pacemaker placement. Conclusion: Recurrent syncope is an uncommon presentation of carotid body tumors requiring workup to rule out functionality, genetic mutations, and metastases. Management involves a multi-disciplinary approach and individual risk-benefit assessment of treatment options. Presentation: Saturday, June 17, 2023