THU529 Challenges In The Management Of Biochemically Silent Paraganglioma

Disclosure: S. Dewan: None. A. Farooqi: None. J. Jun: None. Biochemically silent Pheochromocytoma and Paraganglioma (PPGL) are rare neuro-endocrine tumors because of which there is low quality evidence and insufficient guidelines for their management. 74-year-old Female was referred to our Endocrine clinic for incidentally discovered Retroperitoneal mass on MRI. On evaluation patient reported having concerns of escalating anxiety, difficult to control HTN and episodic flushing after physical activity in the last one year. A CT abdomen and pelvis with contrast was ordered which showed 1.7 x 1.8 cm mass anterior to the L5 vertebral body just caudal to the aortic bifurcation. The biochemical work up including 24-hour urine Metanephrines (104 ug/24 hr; n 52-341), Normetanephrines (479 ug/24 hr; n 88-444), Total Metanephrines (583 ug/24 hr; n 88-444), 3 Methoxytyramine (166 mcg/24 hr; n <242) was inconclusive. For further evaluation PET CT DOTATATE scan was ordered which showed the lesion to be DOTATAE somatostatin analogue avid, consistent with somatostatin receptor positive neuroendocrine tumor. Patient was scheduled for surgery in 2 weeks and was started on Terazosin in addition to her anti HTN medications Amlodipine, Losartan and HCTZ. The surgery had to be rescheduled due to inadequate blood pressure control. Her amlodipine and Terazosin dosage were gradually increased while the procedure was rescheduled. Eventually she underwent Laparotomy exploration and resection of the lesion. Patient tolerated the procedure well and had no major intra or post operative fluctuations in her blood pressure, heart rate or blood glucose. According to the Endocrine Surgery team, the tumor could not be sufficiently removed since it was immovable during surgery and could not be delineated from the spine. The post-operative CT scan showed nodular lesion at aortic bifurcation slightly increased in soft tissue component from prior CT scan. After discussions with surgery and oncology team, patient opted for imaging surveillance for now and will consider genetic counseling and/or radiation therapy if the tumor increases in size. Untreated PPGL carries a high risk of cardiovascular morbidity and mortality, and some may also be malignant with a propensity to cause mass effects and metastasis. Currently, there are scarce evidence-based studies comparing treatment options in biochemically silent PPGL, and there is no consensus for the most appropriate peri-operative management of biochemically silent PPGL. This case adds to the literature on how a combination of calcium channel blocker and alpha blocker can be used to achieve peri-operative blood pressure and heart rate control with no major side effects. It also demonstrates the importance of functional imaging, especially in clinically or radiologically suspected PPGL, even with a normal biochemical work up. We suggest multi-disciplinary evaluation and individualized management to ensure positive outcomes. Presentation: Thursday, June 15, 2023