Pheochromocytoma is a rare neuroendocrine tumor originating from chromaffin cells of the adrenal medulla, responsible for producing catecholamines such as adrenaline and noradrenaline. These hormones play an essential role in the "fight or flight" response, but their overproduction by pheochromocytomas can lead to severe cardiovascular effects, most notably hypertension.
Cardiovascular Implications
Hypertension is the hallmark symptom of pheochromocytoma, presenting as persistent or episodic blood pressure spikes. These surges often defy conventional antihypertensive therapy, making early recognition vital. Alongside hypertension, patients may exhibit paroxysmal symptoms such as severe headaches, palpitations, profuse sweating, and anxiety. These episodes are triggered by stress, physical activity, or certain medications and result from acute catecholamine release, which also raises the risk of life-threatening complications like arrhythmias, stroke, or myocardial infarction.
Advancements in Diagnosis
Modern diagnostic protocols emphasize biochemical and imaging methods. Plasma-free metanephrines and urinary fractionated metanephrines are highly sensitive tests, detecting elevated catecholamine metabolites. Imaging, including high-resolution CT or MRI scans, confirms tumor localization. For cases with metastatic or extra-adrenal pheochromocytomas, functional imaging like ^68Ga-DOTATATE PET/CT or ^123I-MIBG scintigraphy is increasingly utilized. Genetic testing is also recommended, as approximately 30-40% of pheochromocytomas are linked to hereditary syndromes like multiple endocrine neoplasia (MEN) type 2 or von Hippel-Lindau disease.
Treatment and Management
Surgical removal remains the definitive treatment. However, preoperative management is critical to mitigate perioperative risks. Patients are started on alpha-blockers, such as phenoxybenzamine or doxazosin, to stabilize blood pressure. Beta-blockers may follow once adequate alpha-blockade is achieved, preventing unopposed alpha-adrenergic activity. Advances in minimally invasive surgical techniques, including laparoscopic adrenalectomy, have significantly improved recovery and reduced complications.
Prognosis and Challenges
Early detection and intervention dramatically improve outcomes, with most patients achieving normotension post-surgery. Delayed diagnosis, however, can lead to irreversible cardiovascular damage or metastasis, underscoring the need for awareness among clinicians. Research continues into optimizing screening for hereditary cases and improving therapies for malignant pheochromocytomas.
Pheochromocytoma: A Rare but Critical Cause of Hypertension
