From the Guidelines
Pheochromocytoma should be managed with alpha-blockers like doxazosin, followed by beta-blockers, and surgical removal of the tumor after adequate pharmacological preparation, as recommended by the most recent guidelines 1.
Diagnosis and Treatment
Pheochromocytoma is a rare tumor that develops in the adrenal glands, causing excessive production of catecholamines (adrenaline and noradrenaline). This condition typically presents with episodic symptoms including severe headaches, sweating, palpitations, anxiety, and dangerously high blood pressure.
- Diagnosis requires biochemical testing, primarily plasma free metanephrines, which carries a 99% sensitivity and an 89% specificity 1.
- Imaging studies like CT, MRI, or MIBG scans should be used to locate the tumor.
- The definitive treatment is surgical removal of the tumor (adrenalectomy), but patients must be properly prepared with medication before surgery.
Medication and Surgery
- Alpha-blockers like doxazosin should be started 1-2 weeks before surgery to control blood pressure, followed by beta-blockers like propranolol only after adequate alpha blockade to prevent hypertensive crisis 1.
- Calcium channel blockers like nifedipine may be added if blood pressure remains uncontrolled.
- After surgery, patients require lifelong follow-up to monitor for recurrence, especially in cases of familial syndromes like MEN2, von Hippel-Lindau disease, or neurofibromatosis type 1, which are associated with pheochromocytoma.
Genetic Testing
- Genetic testing is recommended for all patients, particularly those with bilateral tumors, family history, or young age at diagnosis, as approximately 40% of cases have a genetic basis 1.
- Identifying a single tumor mandates surgical excision after adequate pharmacological preparation, because secreting PPGLs can cause fatal events with no warning.
- Administering doxazosin or terazosin, followed by a beta-blocker, usually controls BP and adrenergic crises 1.
From the FDA Drug Label
Phenoxybenzamine hydrochloride capsules are indicated in the treatment of pheochromocytoma, to control episodes of hypertension and sweating. If tachycardia is excessive, it may be necessary to use a beta-blocking agent concomitantly.
- Pheochromocytoma treatment: Phenoxybenzamine is indicated for the treatment of pheochromocytoma to control episodes of hypertension and sweating.
- Concomitant use: A beta-blocking agent may be necessary to use concomitantly if tachycardia is excessive 2.
From the Research
Definition and Presentation
- Pheochromocytomas are rare, mostly benign catecholamine-producing tumors of chromaffin cells of the adrenal medulla or of a paraganglion 3.
- Typical clinical manifestations are sustained or paroxysmal hypertension, severe headaches, palpitations, and sweating resulting from hormone excess 3, 4.
- The presentation of pheochromocytomas is highly variable and can mimic many other diseases 3, 4, 5.
Diagnosis
- The diagnosis of pheochromocytomas depends mainly upon the demonstration of catecholamine excess by 24-h urinary catecholamines and metanephrines or plasma metanephrines 3.
- They are localized by a computed tomography scan and magnetic resonance imaging of the adrenal glands and abdomen; complementary 123I-metaiodobenzylguanidine scintigraphy and 18F-dihydroxyphenylalanine-positron emission tomography are available 3.
- A high index of clinical suspicion coupled with careful clinical evaluation and laboratory testing is key to reaching the diagnosis 4.
Treatment
- Laparoscopic and adrenal sparing surgical intervention following preoperative alpha-blockade is the treatment of choice and usually curative 3, 6.
- For malignant pheochromocytomas, radiotherapy and chemotherapy are palliative treatment options 3, 6.
- Chronic medical therapy is indicated in the form of alpha- and/or beta-blockade or inhibition of catecholamine synthesis with alpha-methyl-para-tyrosine for patients with inoperable, malignant, recurrent, or multicentric pheochromocytomas 4, 6.
Prognosis and Management
- With proper treatment, the outlook for patients with pheochromocytoma is excellent 4.
- If undiagnosed or untreated, pheochromocytoma causes serious complications and death 3, 4.
- An understanding of the pathophysiology and natural course is vital to the rational management of patients with pheochromocytoma 4, 5, 7.