Pheochromocytoma masquerading as acute coronary syndrome with cardiogenic shock was diagnosed via markedly elevated plasma metanephrines and adrenal imaging, with complete cardiac recovery following laparoscopic adrenalectomy after preoperative alpha-blockade.
Key Findings
Background
A 59-year-old man presented with acute cardiogenic shock and markedly elevated cardiac biomarkers that initially suggested acute coronary syndrome.
The patient had a 10-year history of intermittent chest tightness prior to the acute presentation.
Peak troponin I level was 5.48 ng/mL.
N-terminal pro-B-type natriuretic peptide (NT-proBNP) level was 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.
Background
Coronary angiography demonstrated no significant coronary artery stenosis, consistent with myocardial infarction with non-obstructive coronary arteries (MINOCA).
The absence of obstructive coronary artery disease in the setting of cardiogenic shock and elevated troponin prompted further evaluation.
The MINOCA finding was the key diagnostic turning point leading to investigation for alternative etiologies.
This pattern is described as a common scenario in which pheochromocytoma misdiagnosis occurs.
Background
Plasma free metanephrines were massively elevated, confirming biochemical evidence of pheochromocytoma.
Plasma free normetanephrine level was 653.9 pg/mL, described as greater than 680 times the upper limit of normal.
Plasma free metanephrine level was 378.5 pg/mL, described as greater than 630 times the upper limit of normal.
These extreme elevations were the key biochemical finding leading to the diagnosis.
Background
Abdominal computed tomography identified a right adrenal mass, and histopathology confirmed pheochromocytoma after surgical resection.
The adrenal mass was identified on abdominal CT imaging.
The patient underwent laparoscopic adrenalectomy.
Histopathological examination of the resected specimen confirmed the diagnosis of pheochromocytoma.
Background
Preoperative management consisted of alpha-blockade with phenoxybenzamine and volume expansion for 2 weeks prior to surgery.
Phenoxybenzamine was the alpha-blocking agent used.
The preoperative preparation period lasted 2 weeks.
Volume expansion was performed alongside alpha-blockade as part of hemodynamic stabilization.
Conclusions
Following laparoscopic adrenalectomy, cardiac function normalized and symptoms completely resolved.
Postoperative normalization of cardiac function confirmed the reversibility of catecholamine-induced cardiomyopathy.
Symptoms completely resolved after tumor resection.
The authors conclude that 'catecholamine-induced cardiomyopathy is reversible after tumor resection.'
Conclusions
The authors conclude that pheochromocytoma should be suspected in patients with MINOCA and unexplained cardiogenic shock, particularly when accompanied by labile blood pressure.
Labile blood pressure is highlighted as a key accompanying diagnostic clue.
Substantially elevated plasma metanephrines and adrenal imaging are identified as facilitating early diagnosis.
Multidisciplinary management, 'from hemodynamic stabilization to definitive surgery, is essential.'
Misdiagnosis is described as common when cardiogenic shock and elevated troponin occur without obstructive coronary artery disease.
What This Means
This case report describes a 59-year-old man who arrived at the hospital in a life-threatening state of heart failure (cardiogenic shock) with lab results — including elevated troponin and heart failure markers — that strongly suggested a heart attack. However, when doctors examined his coronary arteries, they found no blockages. This led them to investigate other causes, and they discovered that his blood levels of metanephrines (breakdown products of stress hormones called catecholamines) were hundreds of times higher than normal. An abdominal scan revealed a tumor on his right adrenal gland, which was confirmed by pathology to be a pheochromocytoma — a rare tumor that can release massive amounts of adrenaline-like hormones, damaging the heart.
The patient was treated with medications to block the harmful effects of these hormones (alpha-blockers) and given fluids to stabilize him for two weeks before surgeons safely removed the tumor using minimally invasive laparoscopic surgery. After the operation, his heart function returned to normal and all his symptoms resolved completely. This research suggests that the heart damage caused by pheochromocytoma is not permanent and can fully reverse once the tumor is removed.
This case highlights an important diagnostic challenge: pheochromocytoma can convincingly mimic a heart attack, and when a patient has unexplained heart failure or cardiogenic shock with no blocked coronary arteries, doctors should consider testing for this rare tumor. Labile (fluctuating) blood pressure is noted as an additional warning sign. Early diagnosis through blood tests for metanephrines and imaging of the adrenal glands, combined with careful multidisciplinary management, is key to achieving a good outcome.
Zhang S, Cui Y, Li S. (2026). Pheochromocytoma Masquerading as Acute Coronary Syndrome Complicated by Cardiogenic Shock: A CARE-Compliant Case Report.. The American journal of case reports. https://doi.org/10.12659/AJCR.952994