SAT344 Takotsubo Cardiomyopathy Complicating Cholecystectomy In A Patient With Clinically Silent Pheochromocytoma

Disclosure: K.B. Huynh: None. T.A. Nguyen: None. J.P. Perdomo Rodriguez: None. Introduction: Pheochromocytomas (PCC) are responsible for 85 to 90 % of all catecholamine-secreting tumors, which originate from chromaffin cells of the adrenal medulla. Normotensive Incidental Pheochromocytoma (NIP) may be a distinct entity and has been reported in up to 55% in case series. Case description: A 48-year-old woman with a history of gestational hypertension presented to the hospital with acute cholecystitis. Shortly after cholecystectomy, she developed severe hypertension and flash pulmonary edema. The hospital course was complicated by an acute ischemic stroke secondary to cardiogenic emboli. She was diagnosed with Takotsubo cardiomyopathy, and a transthoracic echocardiology (TTE) revealed an ejection fraction (EF) between 20% and 45 %. CT scan of the abdomen/pelvis revealed a complex 8.3 x 6.2 x 0.6 centimeter left adrenal tumor. PET DOTATE has been declined. She was discharged on carvedilol 25 mg twice daily but not on ACE inhibitors due to soft blood pressure. She was referred to outpatient endocrinology for pheochromocytoma. Metanephrine level was elevated to 1023 pg/mL, normetanephrine was 2209 pg/mL and the total level was 3232 pg/mL. Adrenal steroids including aldosterone, cortisol, and DHEA sulfate were within normal limits. Chromogranin A was normal. Germline genetic analysis was negative. Hypertension was treated with prazosin titrated slowly to 8 mg three times daily, and carvedilol was continued. Home blood pressure readings ranged between 85/55 and 113/72 without orthostatic hypotension. Pulse ranged between 55 and 73 beats per minute. Weeks later, left adrenalectomy was aborted due to hypertension urgency and bradycardia. However, a TTE revealed normal EF. Carvedilol was discontinued, and treatment was changed to nifedipine and phenoxybenzamine, which was titrated to 40 mg three times daily until she became orthostatic over 4 weeks. She underwent successful left adrenalectomy. Discussion: Normotensive pheochromocytomas have been described in 13.5 % to 55% of incidental pheochromocytoma series. Moreover, hypertensive crises have been reported following surgery in patients with unsuspected pheochromocytoma. Hence, plasma metanephrines should be checked in all adrenal incidentalomas. While normotension is thought to mostly occur when the tumor is too small, a study by Haissaguerre et al found no correlation between size and biochemical parameters in NIP, and the NIP group was characterized by a global reduction in catecholamine and metanephrine secretion and a mean size of 52 +/- 6.7 millimeters. Our case was a much larger pheochromocytoma with 18- and 15-fold elevation in metanephrine and normetanephrine respectively. It has been described that normotensive pheochromocytoma exhibit down-regulation of different proteins involved in key processes of catecholamine metabolism that may lead to reductions in the storage and release of catecholamines. Presentation: Saturday, June 17, 2023