What is the initial management of pheochromocytoma?

Initial Management of Pheochromocytoma

The initial management of pheochromocytoma requires immediate initiation of alpha-adrenergic blockade for 7-14 days before proceeding to definitive surgical resection, which is the only curative treatment. 1, 2

Preoperative Medical Management: The Critical First Step

Alpha-Blockade is Mandatory

• Begin alpha-adrenergic blockade within 24-48 hours of diagnosis and continue for at least 7-14 days before any surgical intervention to prevent perioperative hypertensive crises and reduce mortality 1, 2, 3
• Gradually titrate the alpha-blocker dose upward to achieve target blood pressure goals of <130/80 mmHg when supine AND systolic blood pressure >90 mmHg when standing 1, 2, 3
• Phenoxybenzamine or doxazosin are the preferred alpha-blocking agents 3
• Calcium channel blockers can be added as adjunctive therapy for refractory hypertension that persists despite adequate alpha-blockade 4, 1, 3

Beta-Blockade: Only After Alpha-Blockade

• Never initiate beta-blockers before establishing adequate alpha-blockade - this is a critical error that can precipitate a fatal hypertensive crisis from unopposed alpha-adrenergic stimulation 1, 2, 3
• Beta-blockers (preferably β1-selective agents) should only be added after adequate alpha-blockade if tachycardia or tachyarrhythmias persist 1, 3, 5

Volume Expansion and Preoperative Preparation

• Implement a high-sodium diet and administer 1-2 liters of intravenous saline 24 hours prior to surgery to prevent orthostatic and postoperative hypotension 1, 3
• Use compression stockings to further reduce the risk of postoperative hypotension 1
• This volume expansion serves the dual purpose of preventing the profound hypotension that commonly occurs after tumor removal when catecholamine levels suddenly drop 3

Alternative Medical Therapy: Metyrosine

• Metyrosine (a tyrosine hydroxylase inhibitor) is FDA-approved for preoperative preparation and can reduce catecholamine biosynthesis by 35-80% 6
• It is indicated for preoperative preparation, management when surgery is contraindicated, or chronic treatment of malignant pheochromocytoma 6
• The maximum biochemical effect occurs within 2-3 days, with most patients experiencing decreased frequency and severity of hypertensive attacks 6

Diagnostic Imaging Before Surgery

• Obtain CT or MRI of the abdomen immediately to localize the tumor and assess for bilateral disease, extra-adrenal paragangliomas, or metastatic disease 2, 3, 7
• Never perform fine needle biopsy of a suspected pheochromocytoma - this is absolutely contraindicated and can trigger a fatal hypertensive crisis 2, 3, 8

Definitive Surgical Management

Surgical Approach

• Laparoscopic adrenalectomy is the preferred surgical approach for most pheochromocytomas and is considered the gold standard for tumors ≤6 cm in diameter 1, 2, 9
• Open surgery should be reserved for tumors with high suspicion of malignancy, large size (>5-6 cm), or evidence of local invasion 1, 3, 9
• Complete surgical extirpation (R0 resection) is the only curative treatment and the mainstay of potentially curative approaches 4, 2, 3

Intraoperative Management

• Treat intraoperative hypertensive episodes with magnesium sulfate, phentolamine, calcium antagonists, nitroprusside, or nitroglycerin 2, 3
• Anticipate and aggressively treat postoperative hypotension with fluid resuscitation, as this is a common complication after tumor removal 2, 3

Postoperative Care and Confirmation of Cure

• Monitor glucose levels closely - hypoglycemia commonly occurs after catecholamine levels drop following tumor removal 2, 3
• Measure plasma or urine metanephrines at 2-8 weeks postoperatively to confirm complete tumor removal 1, 2, 3, 5
• Gradually wean antihypertensive medications as tolerated 3

Long-Term Surveillance: Lifelong Monitoring Required

• All patients require lifelong surveillance due to a 10-15% recurrence risk, with recurrences reported as late as 41 years after initial resection 2, 3, 5
• Clinical monitoring (blood pressure, adrenergic symptoms) every 3-4 months for the first 2-3 years, then every 6 months 2, 3
• Biochemical testing (plasma/urine metanephrines, chromogranin A) every 3-4 months for 2-3 years, then every 6 months 2, 3
• Whole-body MRI at least every 2-3 years to detect recurrence or metastases 3

Special Populations

Pregnancy

• For pheochromocytoma diagnosed within the first 24 weeks of gestation: perform laparoscopic adrenalectomy after 10-14 days of medical pre-treatment with alpha-adrenergic blockade 1
• If diagnosed in the third trimester: continue medical management until fetal viability, then perform cesarean section with tumor removal in the same surgical session 1

Critical Pitfalls to Avoid

• Never start beta-blockers before alpha-blockade - this is the most dangerous error in management 1, 2, 3
• Never biopsy a suspected pheochromocytoma 2, 3, 8
• Do not proceed to surgery without adequate preoperative alpha-blockade for at least 7-14 days 1, 2
• Biochemical evidence of excess catecholamine production usually precedes clinical manifestations when tumors recur, making biochemical surveillance essential 5