SUN-496 - The Mystery of Paroxysmal Hypertension: Pseudopheochromocytoma in Rural Appalachia

Introduction:
Pseudopheochromocytoma, first described by Kuchel in 1981, Severe hypertensive episodes (BP >200/110 mmHg) lasting 10 minutes to 2 days, with headache, diaphoresis, nausea, and fatigue, typically associated with emotional trauma or defensive personality styles. Despite 67% of patients having experienced emotional trauma, psychological components are often denied.

Case:
A 69-year-old female with history for CAD, carotid artery stenosis, DM Type 2, COPD, hypertension, neuropathy, and fibromyalgia, anxiety presented with a BP of 164/99, this was the third paroxysmal hypertensive episode accompanied by seizure-like activity (negative EEGs consistent with prior presentations), confusion, slurred speech, right-sided numbness, and tingling. With unremarkable imagining results.
The primary care team scheduled follow-ups with neurology, endocrinology, and nephrology for comprehensive care. Remarkably, extensive diagnostic workup returned within normal ranges, including urine metanephrines, normetanephrine, norepinephrine, epinephrine, vanillylmandelic acid, 5-HIAA, aldosterone, and cortisol, the nephrology team established working diagnosis of pseudopheochromocytoma. Management strategy included Carvedilol, Citalopram, Diazeopam. At 1-year follow-up, no further paroxysmal episodes were noted.

Discussion:
Clinical significance: In paroxysmal hypertension cases - only 2% are caused by True pheochromocytomas. When excluded, pseudopheochromocytoma and other mimics (sleep apnea, panic disorder, drugs) are frequently missed, leading to excessive testing. Recognition remains poor.
The pathophysiology remains unclear but involves sympathetic nervous system dysregulation. Patients show heightened catecholamine responses to glucagon stimulation and exaggerated blood pressure spikes during Valsalva maneuvers, indicating adrenoreceptor hypersensitivity—unlike pheochromocytoma patients whose receptors are desensitized from chronic catecholamine exposure.
Diagnosis requires comprehensive testing, Pseudopheochromocytoma is a diagnosis of exclusion. Pheochromocytoma must be ruled out with biochemical testing (>2-fold elevation in urine catecholamines, elevated urine metanephrines, or >4-fold increase in plasma metanephrines) and imaging (MRI or CT) to exclude tumor.
Alpha-beta blockade with separate agents (atenolol and doxazosin) provides symptomatic relief. However, primary treatment should address underlying psychological factors using SSRIs and benzodiazepines.

Conclusion:
Pseudopheochromocytoma, though underappreciated, is a common cause of symptomatic paroxysmal hypertension. As a diagnosis of exclusion, it requires heightened clinical awareness to improve patient outcomes and prevent mismanagement.

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