SAT-226 Lifestyle Modifications or Adrenalectomy? Pheochromocytoma Presenting with New Onset Diabetes Mellitus

Abstract Introduction When clinicians think of pheochromocytomas, diabetes might not be the first thing that comes to mind. Pheochromocytomas elicit deterioration in glucose tolerance in 20% to 40% of affected individuals. Size of the pheochromocytoma could be an independent risk factor for developing diabetes, as larger pheochromocytomas often present with diabetes mellitus in 23% to 33% of patients with symptomatic pheochromocytomas. Evidence suggests that pheochromocytoma proposes a risk for development of diabetes. There is no consensus or recommendations on which patients with new onset diabetes should be screened for pheochromocytoma or how to manage hyperglycemia in these patients. Clinical Case 42 YO F with PMH of HTN presented to primary care clinic c/o polyuria, fatigue, 25-pound weight loss, epigastric pain and worsening hypertension over 3 months. Initial work up showed a HbA1C of 9%. The patient was diagnosed with type 2 diabetes mellitus and started on Metformin 1g BID with no improvement of glucose levels or symptoms. As part of initial work up for suspicion of pancreatic malignancy patient had an abdominal CT scan showing a 5.6 x 4.8 cm well-circumscribed left adrenal mass. Patient was referred for endocrine evaluation. Initial workup showed negative GAD Ab, normal 1mg Dexamethasone suppression test, normal aldosterone/renin ratio, elevated Free Normetanephrine of 17,921 pg/mL and elevated chromogranin A of 3,427 ng/mL. Based on biochemical evidence of catecholamine excess and left adrenal mass on imaging, patient was diagnosed with Pheochromocytoma. MIBG showed no evidence of metastatic disease. She was started on insulin therapy, Doxazosin 1mg BID which was titrated to 2mg BID and Amlodipine 5mg was increased to 10mg daily. Pt was referred to surgery for adrenalectomy. On pre-op evaluation patient had significant improvement of glucose levels and symptoms. Propranolol 20mg BID was started for BP optimization. A laparoscopic left adrenalectomy was performed without complications. Patient did not require anti-hypertensive medications or insulin during hospitalization and was discharged on metformin 500mg daily with no anti-hypertensive medications. At one-month Post-adrenalectomy follow up patient had normal BP of 116/72 mmHg and A1C of 5.4% with normal glucose logs indicating resolution of diabetes and HTN post adrenalectomy. Conclusion Diabetes is a multifactorial disease that has direct impact on patient’s quality of life, morbidity and mortality. It is important to consider pheochromocytoma as a risk factor for development of diabetes, especially in young patients with atypical presentation, uncontrolled hypertension or without evidence of antibodies or insulin resistance. Screening and early diagnosis of pheochromocytoma could mean significant reduction on long term diabetes complications as diabetes seems to improve or even resolve after adrenalectomy.