MON-387 Pheochromocytoma Masquerading as Vasomotor Menopausal Symptoms

Introduction Pheochromocytoma and paraganglioma are neuroendocrine tumors arising from chromaffin cells. There are approximately 500-1600 new cases of combined pheochromocytoma and paraganglioma in the United States per year. Most of the cases occur between the 3rd and 5th decade of life. Recent studies demonstrate that more than 50 percent of these tumors are asymptomatic. Case We present a 58 year old female with no significant past medical history, referred to endocrinology division for treatment of vasomotor symptoms of menopause. Her last menstrual period was 6 years ago. She had noticed generalized profuse diaphoresis, intermittent lightheadedness, anxiety and hot flashes that had started in perimenopause. The diaphoresis had limited her outside activities. She denied hypertension, tachycardia and headaches. She denied hormonal replacement therapy for menopausal symptoms and paroxetine had not helped her symptoms in the past. When evaluated in endocrinology, we reviewed her past records and noticed the presence of a right adrenal nodule on a CT abdomen from 2010. Biochemical evaluation showed elevated plasma normetanephrine at 1.9 (<0.90 nmol/l) with normal metanephrine at <0.20 (<0.50 nmol/l). 24 hour urine fractionated catecholamines and metanephrines results: Dopamine 121 (65-400 mcg), epinephrine 9.0 (<21 mcg), norepinephrine 170 (15-80 mcg), metanephrine 130 (<400 mcg), normetanephrine 1074 (<900 mcg) and total metanephrines 1204 (<1300 mcg). She had normal urinary cortisol, serum DHEA-S, serum aldosterone, plasma renin and serum calcium. MRI of adrenal glands reidentified a 1.7 cm right adrenal nodule suspicious for pheochromocytoma, that had doubled in size compared with prior images. Patient was prepared preoperatively with phenoxybenzamine and propranolol. She underwent right adrenalectomy and pathology was positive for pheochromocytoma. Four weeks post surgery, repeat plasma normetanephrine normalized at 0.28 (<0.90 nmol/l) and repeat 24 hour urine collection showed that norepinephrine normalized at 29 (15-80 mcg) and normetanephrine normalized at 285 (<900 mcg). Patient had complete resolution of presenting symptoms after adrenalectomy. Genetic testing is currently pending. Conclusion Our patient presented at 58 years old with symptoms masquerading as vasomotor menopausal symptoms that in retrospect predated perimenopause. Careful history, physical exam and past records review are important to best assist our patients. Adrenal nodules, independent of size, should undergo biochemical evaluation for hormonal excess, as per the Endocrine Society guidelines. Lack of typical symptoms of pheochromocytoma does not exclude this diagnosis as typical symptoms are seen with larger tumor size. Recent review studies demonstrate that more than half of pheochromocytoma cases are diagnosed serendipitously.