When beta-blocker unmasks the diagnosis: pheochromocytoma mimicking acute coronary syndrome. A case report.

Pheochromocytoma is a catecholamine-producing neuroendocrine neoplasm classically associated with secondary hypertension. We describe the case of a 63-year-old male who presented with intermittent precordial discomfort, paroxysmal hypertensive episodes, and a mild rise in cardiac troponin levels. He was referred to our institution with a presumptive diagnosis of acute coronary syndrome. Serial admission electrocardiograms showed no dynamic ischemic changes, and transthoracic echocardiography demonstrated preserved global systolic function without regional wall motion abnormalities. A noninvasive ischemic workup was therefore planned. Before performing coronary computed tomographic angiography (CCTA), the patient received propranolol, after which he developed a hypertensive crisis accompanied by recurrent precordial pain; an identical episode occurred following a second beta-blocker dose. CCTA ruled out flow-limiting coronary artery stenoses. In view of the clinical context, pheochromocytoma was suspected. Contrast-enhanced abdominal computed tomography identified a left adrenal mass, and urinary metanephrines were elevated. The patient underwent adrenalectomy, and histopathological examination confirmed a benign pheochromocytoma. Postoperative recovery was uneventful, and the patient remains asymptomatic at follow-up.