8793 Bilateral Pheochromocytoma Related To Multiple Endocrine Neoplasia Syndrome 2

Abstract Disclosure: F. Compas: None. Background: Pheochromocytomas are rare catecholamine secreting neuroendocrine tumors of the adrenal medulla that overproduce metanephrines. These tumors may occur sporadically or arise from several genetic disorders including Multiple Endocrine Neoplasia Type 2 (MEN 2). Symptoms of a pheochromocytoma are hypertension, palpitations, anxiety, headache, diaphoresis, and tremors. Bilateral pheochromocytomas are exceedingly rarer compared to unilateral cases. Clinical Case: A 30-year-old male without significant past medical history initially presented to his primary care physician at the age of 18 with episodic palpitations that occurred at least once a week during exercise. Over the years the palpitations progressed and were accompanied by intermittent chest pain. Family history included a mother with thyroid nodules who died from multiple organ failure. Extensive cardiac evaluation revealed hypertension, leading to beta-blocker initiation. He underwent further testing for causes of secondary hypertension. Shortly after he presented to the emergency room with sudden onset aphasia, confusion, and combativeness. CT scan was performed which revealed posterior reversible encephalopathy syndrome. Abdominal imaging from secondary hypertension workup revealed bilateral adrenal masses. Urine metanephrines revealed a metanephrine of 67,950 mcg/24 hr and urine normetanephrine of 27,150 mcg/24 hr. He was admitted to the hospital. In preparation for bilateral adrenalectomy alpha blockade was initiated followed by beta blockade. He underwent a bilateral adrenalectomy. Pathology from adrenalectomy revealed that bilateral masses consistent with a bilateral pheochromocytoma. Shortly afterwards he was diagnosed with medullary thyroid cancer. Genetic testing revealed that this patient had MEN 2a syndrome. Discussion Bilateral pheochromocytomas from MEN 2a syndrome are exceptionally rare, accounting for a small percentage of all cases. They present more severe and cause fluctuating hypertension due to the simultaneous release of catecholamines from both adrenal glands. This case highlights the importance of considering rare causes of hypertension and the implications of delayed diagnosis and treatment. Conclusion: This is an exceedingly rare case of a bilateral pheochromocytoma implicated by MEN 2a that went undetected for years and presented with life threatening complications. Presentation: 6/2/2024