PSAT027 An Incidentally-Discovered Retro-Cardiac Paraganglioma Presenting as NSTEMI
Authors: Bal Simrun , Lee Alicia , Chaidarun Sushela 
Published: November 2022

Abstract

Introduction/Background
Paragangliomas are rare tumors arising from extra-adrenal chromaffin tissue (1,2). The majority of paragangliomas occur in the head and neck, with the heart representing an uncommon site (3). We present a rare case of a patient who was incidentally found to have a hypersecretory retro-cardiac paraganglioma.

Clinical Case
A 72-year-old woman with a history of hypertension, hyperlipidemia, migraines, and prior cerebrovascular accident presented to the Emergency Department with sudden, substernal, pleuritic chest pain. She described weeks of a "fluttering sensation" in the chest with one episode of syncope. She denied shortness of breath or diaphoresis. Vitals were normal and EKG did not demonstrate ischemia. Troponin uptrended and the patient was admitted due to concern for non-ST-elevation myocardial infarction (NSTEMI).
She promptly underwent cardiac catheterization which revealed non-obstructive coronaries and a left atrial mass with blood supply from the right coronary artery and the left circumflex artery. Cardiac MRI demonstrated an extracardiac, interpericardial 42×24×37 mm mass below the left atrium without aggressive features, and delayed homogenous enhancement with dynamic perfusion, suggestive of a paraganglioma.
Biochemical evaluation demonstrated elevated free plasma normetanephrines of 5.5 nmol/L (normal: &lt; 0.90 nmol/L) and normal free plasma metanephrines. Chromogranin-A was elevated at 454 ng/ml (normal: &lt;93 ng/ml). 24-hour urine total urine metanephrines were markedly elevated at 1438 mcg/24h (normal: 180-646 mcg/24h) with mainly urine normetanephrines of 1390 mcg/24h (normal: 148-560 mcg/24h). The patient's TSH, free T4, and total T3 were normal. PET/CT scan was negative for metastatic disease. The patient denied a family history of paraganglioma or pheochromocytoma.
She was seen in follow-up with Cardiac Surgery, who felt the resection would be technically difficult, but that there were no other alternatives. The patient's procedure was postponed due to a COVID-19 surge and patient was begun on alpha- and beta-blockade, instead of pure alpha-blockade with phenoxybenzamine, in view of her recent history of NSTEMI.

Conclusion
We present a rare case of an incidentally-found cardiac mass, discovered during cardiac catheterization, with biochemical and radiographic evaluations concerning for a retro-atrial paraganglioma. Cardiac paragangliomas can present with a range of symptoms, from hypertension to different obstructive symptoms, including ischemia, depending on the tumor's location. The secretory activity of cardiac paragangliomas can also vary; the literature reports that about 31% are biochemically active (2). Though rare, our case highlights the importance of understanding the atypical presentation and evaluation of cardiac paragangliomas.

References
1. Lenders J, et al. Pheochromocytoma. Lancet 2005; 366(9486): 65-675. 2. Chen H, Sippel RS. North American Neuroendocrine Tumors Society consensus guidelines for diagnosis and management of neuroendocrine tumors. Pancreas 2010; 39 (6): 775
3. Erickson D, et al. Benign paragangliomas: clinical presentation and treatment outcomes in 236 patients. J Clin Endocrinol Metab 2001;86(11): 5210-5216.
Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.