Do all patients require ruling out pheochromocytoma before surgery?

Pheochromocytoma Screening Before Surgery

Not all patients require pheochromocytoma screening before surgery—only specific high-risk populations need biochemical testing, including patients with adrenal masses, those with MEN2 or familial syndromes, and anyone undergoing adrenal surgery regardless of indication.

Who Must Be Screened

Patients with Adrenal Masses

• All patients with adrenal masses >10 HU on non-contrast CT must be screened for pheochromocytoma with plasma or 24-hour urinary metanephrines 1
• Patients with any signs or symptoms of catecholamine excess (headaches, sweating, palpitations, hypertension) require screening regardless of imaging characteristics 1
• Never perform adrenal biopsy without excluding pheochromocytoma first, as this can trigger life-threatening hypertensive crisis 1, 2

Patients with Genetic Syndromes

• All patients with MEN2A, MEN2B, or familial medullary thyroid carcinoma require pheochromocytoma screening before any planned surgery, regardless of age 3
• This includes screening before thyroidectomy, even in young children with RET mutations 3
• Biochemical screening with plasma free metanephrines and normetanephrines, or 24-hour urinary fractionated metanephrines, is mandatory 3

Patients Undergoing Adrenal Surgery

• Any patient scheduled for adrenalectomy must have pheochromocytoma excluded preoperatively, even if the mass appears to be metastasis from another malignancy 3
• This applies regardless of the suspected diagnosis (aldosteronoma, cortisol-secreting adenoma, metastasis) 3

Why This Matters

Catastrophic Surgical Complications

• Undiagnosed pheochromocytoma causes hypertensive crisis during surgery, which is frequently fatal 3, 4
• In autopsy series, 76% of pheochromocytomas were clinically unsuspected, and hypertensive/hypotensive crisis precipitated by surgery was a common cause of death 4
• Coexisting pheochromocytoma must be diagnosed and prospectively treated to avoid hypertensive crisis during surgery 3

Preoperative Management Requirements

• Pre-operative alpha-adrenergic blockade is essential for patients with catecholamine-secreting pheochromocytomas to mitigate risk of intra-operative hypertensive crisis 3
• Pheochromocytomas should be removed first (with appropriate alpha-blockade) before any other planned surgery in MEN2 patients 3
• Alpha-adrenergic blockade (phenoxybenzamine) or α-methyltyrosine must be initiated before thyroid surgery 3

Who Does NOT Need Routine Screening

General Surgical Population

• Patients without adrenal masses, genetic syndromes, or signs/symptoms of catecholamine excess do not require routine pheochromocytoma screening before surgery 1
• The prevalence in the general hypertensive population is <0.05%, making universal screening impractical 5

Specific Clinical Scenarios Requiring Screening

• New-onset hypertension with sudden worsening 6
• Development of diabetes mellitus in a hypertensive patient 6
• Family history of MEN, neuroectodermal tumors, or pheochromocytoma 6
• Labile or accelerated hypertension 4
• Hypertension with headaches, sweating, or palpitations (present in 95% of cases) 5

Diagnostic Testing Approach

Most Sensitive Tests

• Plasma free metanephrines is the most sensitive and specific test for diagnosing pheochromocytoma 1
• Plasma free metanephrines and fractionated urinary metanephrines have approximately 100% sensitivity for both sporadic and familial pheochromocytomas 5
• Urinary metanephrines have 97% sensitivity 7

Imaging After Biochemical Confirmation

• Imaging should only follow biochemical confirmation—never perform imaging without biochemical testing first 3
• MRI of the abdomen and pelvis (with and without contrast) is preferred in pediatric populations to avoid ionizing radiation 3

Critical Pitfalls

• Relying solely on radiological appearance to predict hormone secretion status is unreliable—functional testing is essential 1
• At least 5% of pheochromocytoma patients are normotensive, so normal blood pressure does not exclude the diagnosis 5
• Symptoms like headache, sweating, and palpitations are nonspecific but occur more frequently when pheochromocytoma is present 4
• Biochemical evidence of excess catecholamine production usually precedes clinical manifestations when tumors recur 6