SAT-490 Uncovering a Rare Cause of Treatment-Resistant Hypertension: A Case Study of Pheochromocytoma

Abstract Disclosure: K. Sagani: None. J. Cherukara: None. K. Malhotra: None. Hypertension (HTN), a chronic condition with a high prevalence in the United States, is often well managed with standard antihypertensive medications. However, rarely, patients may exhibit treatment-resistant HTN, necessitating further investigation to determine the underlying etiology. One such cause is pheochromocytoma (PCC), a catecholamine-secreting adrenal tumor responsible for 0.2-0.6% of HTN. In this case, a 40-year-old woman has a history of treatment-resistant HTN, despite lack of typical indications such as obesity, poor diet, or kidney disease. Throughout the years, she repeatedly presented to the emergency department (ED) with dyspnea, headaches, excessive unintentional weight loss, tobacco dependence, and generalized anxiety disorder- all nonspecific symptoms. Her systolic blood pressure (BP) was elevated into the 200s, and she was prescribed multiple antihypertensive medications. Despite therapy with various ACE inhibitors, diuretics, and calcium channel blockers, her BP remained poorly controlled. Head CT ruled out neurological pathology, aldosterone studies had negative findings, and abdominal imaging proved inconclusive. Troponin levels were slightly elevated at 7 ng/L, not diagnostic for MI. Suspicion for hyperthyroidism warranted a thyroid ultrasound, which displayed a non-active thyroid nodule. Despite extensive investigation, a differential of secondary HTN due to unknown cause was made. At an ED follow up, the patient’s urine metanephrines (MN) proved to be only slightly elevated, however still increased from the year prior. Although her MN are not 3-4 fold of normal, which is indicative of a PCC, the diagnosis could be made due to ruling out other causes of her refractory HTN. In addition, her allergy to spironolactone and other first-line treatments prevented effective control of her PCC symptoms, which would have been managed otherwise. Had she not presented with an allergy to certain medications, it is possible that her HTN would have been stabilized and the PCC would not have been diagnosed until the tumor produced more MN, as in a typical case. Unfortunately, the absence of continuous care with a general practitioner and endocrinologist led to frequent ED visits without a conclusive treatment plan. Additionally, lack of family history, related gene disorders (MEN 2A/2B), and limited financial resources further created a barrier for this patient. After a proper diagnosis of PCC, treatment can include surgical resection of the tumor, chemotherapy, and symptom management. This case highlights the importance of a systematic approach in evaluating treatment-resistant HTN, particularly by considering secondary causes like PCC, even in the absence of classic symptoms. Presentation: Saturday, July 12, 2025