What is the management for pheochromocytoma?

Management of Pheochromocytoma

The management of pheochromocytoma requires preoperative alpha-adrenergic blockade starting 7-14 days before surgery, followed by complete surgical resection, which is the only definitive treatment. 1

Diagnosis and Initial Evaluation

• Pheochromocytoma is a rare catecholamine-producing tumor with prevalence of 0.01-0.2% in hypertensive patients 1
• Key diagnostic tests:
  • Plasma free metanephrines (highest sensitivity 96-100% and specificity 89-98%)
  • Elevation >4 times upper limit of normal is highly specific 1
  • Imaging studies (CT/MRI) to localize the tumor

Preoperative Management

Alpha-Adrenergic Blockade (First-Line)

• Start 7-14 days before surgery 1
• Options:
  • Phenoxybenzamine (non-selective alpha-blocker): 40-80 mg/day 1, 2
    • FDA-approved specifically for pheochromocytoma 2
    • May provide better control of systolic blood pressure 3
    • Side effects: orthostatic hypotension, nasal congestion, edema
  • Selective alpha-1 blockers (alternatives): doxazosin, prazosin, or terazosin 1
    • Fewer side effects but may require additional antihypertensive medications 3

Beta-Blockers

• Add ONLY AFTER adequate alpha-blockade 1, 2
• For tachycardia or catecholamine-induced arrhythmias
• Using beta-blockers without prior alpha-blockade can worsen hypertension 4

Additional Measures

• Calcium channel blockers: as adjuncts for refractory hypertension 1
• High-sodium diet and 1-2 liters of saline 24 hours before surgery 1
• Compressive stockings to reduce orthostatic hypotension 1

Preoperative Goals

• Supine blood pressure <130/80 mmHg
• Standing systolic blood pressure >90 mmHg 1

Intraoperative Management

Hypertensive Crisis Management

• Phentolamine: IV bolus 5 mg, repeated every 10 minutes as needed 1
• Nicardipine: 5-15 mg/h IV 1
• Sodium nitroprusside: for rapid blood pressure control 5
• Magnesium sulfate: additional option for hypertension control 1

Tachycardia Management

• Esmolol: loading dose 500-1000 μg/kg/min over 1 min, then 50 μg/kg/min infusion 1
• Labetalol: initial 0.3-1.0 mg/kg dose (max 20 mg) slow IV injection every 10 min 1

Surgical Approach

• Complete surgical resection (R0) is the only definitive treatment 1
• Approach based on tumor size and location:
  • Laparoscopic adrenalectomy: for tumors <8 cm without invasion
  • Open surgery: for larger tumors (>5-6 cm) or with evidence of invasion 1
• Surgery should be performed in specialized centers with experience (>10 adrenalectomies per year) 1

Postoperative Care and Follow-up

• Measure plasma/urine metanephrines 8 weeks post-surgery 1
• Imaging at 3-6 months post-surgery 1
• Continue surveillance for at least 10 years
• Lifelong follow-up for genetic cases 1

Management of Metastatic Disease

• Treatment options:
  • Radiopharmaceuticals (131I-MIBG)
  • Locoregional ablative procedures
  • Combination chemotherapy (cyclophosphamide, vincristine, dacarbazine) 1
  • For SDHx-related metastatic disease: temozolomide or tyrosine kinase inhibitors 1

Special Situations

• In pregnant patients with pheochromocytoma:
  • If diagnosed within first 24 weeks: laparoscopic adrenalectomy after alpha-blockade
  • If diagnosed in third trimester: medical management until fetal viability, then cesarean section with tumor removal in same session 6
  • Alpha-blockers and calcium channel blockers are primary treatment options 6

Pitfalls to Avoid

• Never use beta-blockers before adequate alpha-blockade (can worsen hypertension) 6, 4
• Don't underestimate the need for volume expansion before surgery
• Inadequate preoperative alpha-blockade can lead to intraoperative hypertensive crisis 7
• Avoid abrupt discontinuation of alpha-blockers postoperatively

Following this comprehensive approach to pheochromocytoma management will help minimize perioperative complications and improve patient outcomes.