SAT-509 Delayed Diagnosis of Pheochromocytoma: A Six-Year Journey of Intermittent Hypertensive Crises

Abstract Disclosure: U. Irfan: None. S. Shahid: None. A. zara: None. R. thomas: None. S.R. Panja: None. Introduction: Pheochromocytomas are rare neuroendocrine tumors presenting a diagnostic challenge when symptoms are intermittent and biochemical tests are inconclusive. These tumors are characterized by catecholamine production, with potential for normal or mildly elevated metabolite levels, making timely detection difficult. Case Presentation: A 47-year-old female with a history of hypertension and PCOD presented with six years history of recurrent hypertensive crisis, palpitations, anxiety, and flushing. CTA chest done during an ED visit demonstrated an indeterminate 2.5 cm left adrenal nodule. Laboratory investigation including TSH, free T4, plasma ACTH, aldosterone/renin ratio, morning cortisol, urinary cortisol, and plasma metanephrines, were unremarkable at that time. Patient was started on alpha blockers including Doxazosin and Prazosin with only partial relief in her symptoms. In the following months, the patient experienced another episode of severe chest pain prompting an ED visit. She was suspected to have acute coronary syndrome with elevated troponins and EKG changes, though cardiac catheterization was negative. Fortunately, a CT abdomen/pelvis with and without contrast during hospitalization remonstrated the non-lipid rich 2.3 cm left adrenal mass and laboratory tests confirmed the diagnosis of pheochromocytoma with significantly elevated plasma metanephrine (3.19 nmol/L), plasma normetanephrine (4.47 nmol/L), and chromogranin A (1350 ng/mL). Patient was referred for an adrenalectomy and managed with phenoxybenzamine and metoprolol, effectively controlling catecholamine surges and blood pressure in the meantime. A 68Ga-DOTATATE PET/CT scan confirmed a radiotracer-avid left adrenal soft tissue mass, consistent with pheochromocytoma, with no evidence of distant metastasis. Genetic testing was negative for hereditary pheochromocytoma syndromes. The patient underwent a left cortical-sparing partial adrenalectomy, with pathology revealing a well-circumscribed 3.1 x 2.5 x 2.1 cm tumor confined to the adrenal gland. Conclusion: The six-year diagnostic journey demonstrates the challenges of identifying pheochromocytoma, emphasizing the need for persistent and comprehensive evaluation when symptoms remain unexplained. Additionally, it highlights the importance of testing during an episode of adrenergic crisis. Successful surgical intervention and management offer hope for patients with complex, intermittent medical presentation. Presentation: Saturday, July 12, 2025