BACKGROUND
Pheochromocytoma is a rare neuroendocrine tumor arising from chromaffin cells of the adrenal medulla that can manifest as catecholamine-induced cardiomyopathy mimicking acute coronary syndrome. Misdiagnosis is common, particularly when cardiogenic shock and elevated troponin levels occur in the absence of obstructive coronary artery disease. We describe pheochromocytoma masquerading as acute coronary syndrome complicated by cardiogenic shock, highlighting key diagnostic clues and management strategies.
CASE REPORT
A 59-year-old man with a 10-year history of intermittent chest tightness exhibited acute cardiogenic shock, peak troponin I level of 5.48 ng/mL, and N-terminal pro-B-type natriuretic peptide level of 19 800 pg/mL. Initial electrocardiography showed sinus tachycardia and T-wave abnormalities. Echocardiography revealed a reduced left ventricular ejection fraction of 40% with regional wall motion abnormalities. Coronary angiography demonstrated no significant stenosis, consistent with myocardial infarction with non-obstructive coronary arteries (MINOCA). Plasma free normetanephrine and metanephrine levels were 653.9 pg/mL (>680 times the upper limit of normal) and 378.5 pg/mL (>630 times the upper limit of normal), respectively. Abdominal computed tomography identified a right adrenal mass. After 2 weeks of preoperative alpha-blockade with phenoxybenzamine and volume expansion, the patient underwent laparoscopic adrenalectomy. Histopathology confirmed pheochromocytoma. Postoperatively, cardiac function normalized and symptoms completely resolved.
CONCLUSIONS
Pheochromocytoma should be suspected in patients with MINOCA and unexplained cardiogenic shock, particularly when accompanied by labile blood pressure. Substantially elevated plasma metanephrine and adrenal imaging facilitate early diagnosis. Catecholamine-induced cardiomyopathy is reversible after tumor resection. Multidisciplinary management, from hemodynamic stabilization to definitive surgery, is essential.

Keywords: Acute Coronary Syndrome; Cardiogenic Shock; Case Reports; Endocrinology; Myocardial Infarction; Pheochromocytoma