6997 Atypical Presentation of Hereditary Paraganglioma

Abstract Disclosure: O. Abdulhussein: None. R.R. Correa: None. M.D. Lundholm: None. J. Ferri-Guerra: None. G. Madrigol: None. Introduction: Paraganglioma (PGL) is a rare neuroendocrine, highly vascular tumor arising from sympathetic or parasympathetic ganglia chromaffin cells. Some PGL functional while others biochemically silent. Given the possible lack of classic symptoms or convincing catecholamine elevation. They are closely related to pheochromocytomas.• However, the distinction between pheochromocytoma and paraganglioma is essential because of the implication for associated neoplasm and syndromes; paraganglioma is more metastatic. Case: 32-year-old otherwise healthy female presented to primary care clinic for 1 year of dry cough. She was a non-smoker. She denied voice changes, palpitations, hypertension, palpitations, pallor, headache, or diaphoresis, but had noticed a mass growing in her right neck for a year. On exam her blood pressure 107/73 and there was a mobile, round mass felt at the right mandible. CT neck at the time showed reactive lymphadenopathy. She referred to pulmonology and ENT, spirometry and flexible laryngoscopy were unremarkable. For persistent mass 1year later, an MRI of the neck showed a 2.8x2.3x3.8 cm right carotid mass, likely PGL. Biochemical testing revealed elevations in plasma normetanephrine (NM) (269 pg/mL, 18-101 pg/mL) and 24-hour urinary NM (848 ug/24hr, 88-444 ug/24hr) with mild elevation in 24-hour urinary metanephrine (982 ug/24 hr, 140-785 ug/24 hr) and normal plasma metanephrine. The mass was intensely avid on DOTATATE scan without other lesions. Genetic testing uncovered SDHB mutation. She was started on preoperative alpha-blockade with successful resection. She had pathology confirmation of PGL and was set up for annual SDHB surveillance testing. Discussion: A minority of patients with PCC or PGL present with classical “5 P” catecholamine symptoms: pallor, pain, pressure, perspiration, or palpitations. One main reason is a lack of excess catecholamine secretion; 17 years of retrospective data at our center showed that 61% (N=50/82) of patients with PGL with preoperative catecholamine labs had normal levels. Additionally, mild to moderate increases to 2-3x upper limit of normal may be attributed to stress or medications, which obfuscates the distinction between secretory disease and physiologic elevation.Given the infrequency of catecholamine symptoms or secretion, PGL is frequently discovered incidentally. Indeed, 92% (N=110/119) of our PGL cases were found incidentally on imaging or pathology. Alpha-blockade is the preoperative standard of care, many patients are only diagnosed post-operatively by pathology findings. Further study is needed to determine if pre-operative alpha-blockade is needed in all PGL cases, and if so, how we can better identify these patients before they go to the operating room. For now, a high level of suspicion is needed to make a timely PGL diagnosis and facilitate genetic testing. Presentation: 6/1/2024