Phaeochromocytoma Crisis

Topic Overview

Summary

Phaeochromocytoma crisis represents a life-threatening catecholamine surge from a catecholamine-secreting tumour arising from chromaffin cells of the adrenal medulla or extra-adrenal sympathetic ganglia (paragangliomas). This endocrine emergency presents with severe paroxysmal or sustained hypertension, the classic triad of pounding headache, profuse sweating, and palpitations, and can precipitate stroke, myocardial infarction, life-threatening arrhythmias, catecholamine-induced cardiomyopathy, and acute pulmonary oedema. [1,2]

The cornerstone of acute management is alpha-adrenergic blockade FIRST using phentolamine (IV) or phenoxybenzamine (oral), followed only then by beta-blockade to control tachycardia. [3,4] Beta-blockers administered alone without prior alpha-blockade are absolutely contraindicated, as they precipitate unopposed alpha-receptor-mediated vasoconstriction leading to catastrophic hypertension. [5] Definitive treatment is surgical resection (laparoscopic adrenalectomy) after meticulous medical stabilization with alpha-blockade for 10-14 days. [6,7]

Biochemical diagnosis relies on plasma-free metanephrines (sensitivity 96-99%), followed by anatomical imaging with CT or MRI and functional imaging with MIBG or PET for localization and detection of metastases. [8,9] Genetic testing is recommended for all patients, as 30-40% have hereditary mutations (RET, VHL, SDHB/D, NF1), with implications for family screening and surveillance. [10,11]

Key Facts

• Catecholamine storm: Episodic or sustained release of adrenaline, noradrenaline, and dopamine from chromaffin cell tumours
• Classic triad: Severe headache + profuse sweating + palpitations (occurs in 40-60% during crisis) [1,2]
• Treatment priority: Alpha-blockade FIRST (phentolamine 5-10 mg IV bolus or phenoxybenzamine 10-20 mg PO BD), THEN beta-blockade [3,4]
• Critical contraindication: NEVER beta-block before alpha-blockade - causes unopposed alpha-receptor vasoconstriction [5]
• Diagnostic test: Plasma-free metanephrines (sensitivity 96-99%, specificity 89-92%) [8,9]
• Surgical cure: Laparoscopic adrenalectomy after 10-14 days alpha-blockade achieves 90% cure in benign tumours [6,7]
• Hereditary component: 30-40% carry germline mutations - genetic testing recommended for all [10,11]
• Malignant potential: 10-15% are malignant (defined by presence of metastases) - higher with SDHB mutations [12,13]

Clinical Pearls

The "rule of 10s" is outdated (10% extra-adrenal, 10% bilateral, 10% malignant, 10% familial) — modern data shows 30-40% are hereditary, 15-20% extra-adrenal, 10-15% bilateral, and 10-15% malignant. [10,12]

Always alpha-block BEFORE beta-block — beta-blockers alone precipitate catastrophic hypertension via unopposed alpha-receptor vasoconstriction. This is a fundamental pharmacological principle that has caused preventable deaths. [5]

"Spells" with pallor (NOT flushing), profuse sweating, pounding headache, and palpitations = think phaeochromocytoma until proven otherwise. Flushing suggests carcinoid, not phaeochromocytoma. [1,2]

Metoclopramide, glucagon, and certain opioids can precipitate crisis in undiagnosed phaeochromocytoma — maintain high index of suspicion in patients with unexplained paroxysmal hypertension. [14]

Phenoxybenzamine is no longer universally standard — many centers now use doxazosin (selective alpha-1 blocker) with equivalent perioperative outcomes and better tolerability. [15]

Catecholamine-induced cardiomyopathy (takotsubo or dilated) occurs in 11-15% of phaeochromocytomas — reversible after tumor resection but requires preoperative optimization. [16,17]

Why This Matters Clinically

Undiagnosed phaeochromocytoma causes sudden cardiovascular death, stroke, and myocardial infarction. Anesthesia and surgical procedures in patients with unrecognized phaeochromocytoma precipitate catastrophic hypertensive crises with mortality rates of 10-40% if unprepared. [2,18] Every clinician managing hypertensive emergencies, perioperative medicine, or evaluating adrenal incidentalomas must consider phaeochromocytoma, especially when hypertension is paroxysmal, resistant, or associated with the classic triad.

Early recognition and appropriate alpha-blockade prevent life-threatening cardiovascular complications. Genetic testing identifies hereditary syndromes affecting 30-40% of patients, enabling cascade family screening and surveillance for multiple endocrine neoplasia (MEN2), von Hippel-Lindau disease, and succinate dehydrogenase mutations. [10,11]

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Visual Summary

Visual assets to be added:

• Catecholamine biosynthesis pathway diagram (tyrosine → L-DOPA → dopamine → noradrenaline → adrenaline)
• CT showing adrenal phaeochromocytoma (heterogeneous, high attenuation, > 3 cm)
• MRI T2 "light bulb" sign in phaeochromocytoma
• Alpha-before-beta treatment algorithm flowchart
• Hypertensive crisis differential diagnosis flowchart
• MIBG scintigraphy showing adrenal uptake
• Perioperative blood pressure management graph

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Epidemiology

Incidence and Prevalence

Phaeochromocytomas and paragangliomas are rare neuroendocrine tumours with an annual incidence of 2-8 cases per million population. [1,2] However, autopsy series suggest that 50% remain clinically undiagnosed during life, highlighting significant underdetection. [19]

• Prevalence in hypertension: 0.1-0.6% of all hypertensive patients [1]
• Adrenal incidentalomas: Phaeochromocytoma found in 5% of adrenal incidentalomas [20]
• Autopsy detection: 0.05-0.1% of autopsies reveal unsuspected phaeochromocytoma [19]
• Perioperative mortality: Historically 10-40% mortality in undiagnosed cases undergoing anesthesia; now less than 2% with appropriate preparation [18]

Demographics

Associated Hereditary Syndromes

Approximately 30-40% of phaeochromocytomas and paragangliomas occur in the context of hereditary syndromes. [10,11] Genetic testing is recommended for ALL patients regardless of age or family history.

Clinical implications: [10,11]

• SDHB mutations: 30-50% malignancy risk - require intensive surveillance
• MEN2: Screen for medullary thyroid cancer and hyperparathyroidism
• VHL: Screen for CNS hemangioblastomas and renal cell carcinoma
• All first-degree relatives should undergo genetic counseling and testing

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Pathophysiology

Cellular Origin and Catecholamine Synthesis

Phaeochromocytomas arise from chromaffin cells of the adrenal medulla, which originate from neural crest cells. [1,2] Paragangliomas arise from extra-adrenal sympathetic (thorax, abdomen, pelvis) or parasympathetic (head and neck) ganglia. Only sympathetic paragangliomas secrete catecholamines.

Catecholamine biosynthesis pathway:

1. Tyrosine → (tyrosine hydroxylase) → L-DOPA
2. L-DOPA → (DOPA decarboxylase) → Dopamine
3. Dopamine → (dopamine β-hydroxylase) → Noradrenaline
4. Noradrenaline → (phenylethanolamine N-methyltransferase, PNMT) → Adrenaline

Key points:

• Adrenal phaeochromocytomas produce both noradrenaline and adrenaline (PNMT enzyme present)
• Extra-adrenal paragangliomas predominantly produce noradrenaline (PNMT absent)
• Tumours metabolize catecholamines to metanephrines via catechol-O-methyltransferase (COMT)
• Metanephrines are continuously produced in tumour cells (unlike pulsatile catecholamine release), making them superior diagnostic markers [8]

Molecular Pathogenesis

Phaeochromocytomas and paragangliomas are classified into molecular clusters based on underlying genetic alterations: [10,11]

Cardiovascular Effects of Catecholamine Excess

The cardiovascular manifestations of phaeochromocytoma result from activation of adrenergic receptors: [1,2]

Alpha-1 receptors (smooth muscle):

• Intense vasoconstriction → hypertension
• Decreased plasma volume (pressure natriuresis)
• Postural hypotension (chronic vasoconstriction → hypovolemia)

Beta-1 receptors (myocardium):

• Positive inotropy (increased contractility)
• Positive chronotropy (tachycardia, arrhythmias)
• Increased myocardial oxygen demand → ischemia/MI

Beta-2 receptors (smooth muscle, metabolic):

• Vasodilation (adrenaline effect)
• Bronchodilation
• Hyperglycemia (glycogenolysis, gluconeogenesis)
• Hypokalemia (intracellular potassium shift)

Mixed effects:

• Noradrenaline-predominant tumors: Sustained hypertension with reflex bradycardia
• Adrenaline-predominant tumors: Paroxysmal hypertension with tachycardia

Mechanisms of Crisis Precipitation

Catecholamine release is episodic in most phaeochromocytomas, leading to characteristic "spells" or crises. [1,2] Precipitants include:

Mechanical triggers:

• Direct tumor manipulation (palpation, biopsy, surgery)
• Increased intra-abdominal pressure (defecation, micturition, exercise)
• Tumor hemorrhage or necrosis

Pharmacological triggers: [14]

• Dopamine antagonists: Metoclopramide, prochlorperazine
• Opioids: Morphine, fentanyl (histamine-mediated catecholamine release)
• Glucagon (diagnostic test precipitant)
• Glucocorticoids
• Tricyclic antidepressants
• Certain anesthetic agents (desflurane, pancuronium)

Physiological stressors:

• Anesthesia and surgical stress [18]
• Emotional stress
• Pregnancy and labor

Catecholamine-Induced Cardiomyopathy

Sustained or episodic catecholamine excess causes direct myocardial toxicity in 11-15% of phaeochromocytomas. [16,17] Two distinct patterns emerge:

Takotsubo (stress) cardiomyopathy: [16]

• Acute reversible left ventricular apical ballooning
• Mimics acute MI (chest pain, ST elevation, troponin elevation)
• Mechanism: Excessive β-adrenergic stimulation → stunned myocardium
• Reversible after tumor resection in most cases

Dilated catecholamine cardiomyopathy: [17]

• Chronic global left ventricular dysfunction
• Mechanism: Direct catecholamine toxicity → myocyte necrosis, fibrosis
• May require prolonged alpha-blockade before surgery
• Partial reversibility after tumor resection

Predictive factors for cardiomyopathy: [16,17]

• High plasma noradrenaline levels (> 10x upper limit of normal)
• Large tumor size (> 5 cm)
• SDHB mutations
• Adrenaline-secreting tumors (higher association with takotsubo)

Pathophysiology of Unopposed Alpha-Receptor Stimulation

The critical contraindication to beta-blockade before alpha-blockade has a clear physiological basis: [5]

1. Phaeochromocytoma secretes catecholamines activating both alpha and beta receptors
2. Beta-2 receptors mediate vasodilation (opposing alpha-1 vasoconstriction)
3. Beta-blockade removes this vasodilatory effect
4. Unopposed alpha-1 receptor stimulation → severe vasoconstriction
5. Results: Catastrophic hypertension, reduced cardiac output, end-organ ischemia

This principle applies to both non-selective (propranolol) and selective (metoprolol) beta-blockers. Combined alpha-beta blockers (labetalol, carvedilol) have insufficient alpha-blocking potency and should NOT be used as monotherapy. [5]

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Clinical Presentation

Classic Triad

The pathognomonic triad occurs in 40-60% of patients during catecholamine surges: [1,2]

Important distinction: Pallor (not flushing) accompanies the triad due to alpha-mediated vasoconstriction. Flushing suggests alternative diagnoses (carcinoid syndrome, thyroid storm). [1]

Clinical Patterns of Presentation

Phaeochromocytoma manifests in several clinical patterns:

1. Paroxysmal spells (50% of patients): [1,2]

• Duration: Minutes to hours
• Frequency: Daily to monthly
• Trigger-dependent or spontaneous
• Complete symptom resolution between episodes
• Increasing frequency/severity suggests tumor growth

2. Sustained hypertension (30% of patients):

• Persistent hypertension without paroxysms
• Often misdiagnosed as essential hypertension
• Resistant to multiple antihypertensive agents
• May have subtle symptoms (chronic headache, sweating)

3. Hypertensive crisis (10-20% of patients): [2,21]

• Severe hypertension (> 180/120 mmHg) with end-organ damage
• Medical emergency requiring ICU management
• Presentations: Hypertensive encephalopathy, stroke, acute pulmonary edema, MI

4. Normotensive presentation (less than 10% of patients):

• Biochemically active but normotensive
• Discovered as adrenal incidentaloma
• May have non-hypertensive symptoms (palpitations, anxiety, weight loss)
• Extra-adrenal paragangliomas more likely normotensive

5. Perioperative crisis: [18]

• Catastrophic hypertension during anesthesia induction or intubation
• Sentinel event revealing undiagnosed phaeochromocytoma
• Historically associated with 10-40% mortality
• Now rare due to routine screening of adrenal incidentalomas

Symptoms and Signs

Constitutional:

• Weight loss (40-50%) - increased metabolic rate
• Anxiety, sense of impending doom (60-70%)
• Tremor (30-40%)
• Weakness, fatigue

Cardiovascular:

• Hypertension: Paroxysmal (50%), sustained (30%), or crisis (20%)
• Palpitations (60-70%)
• Chest pain (20-30%) - myocardial ischemia or cardiomyopathy
• Arrhythmias: Sinus tachycardia, atrial fibrillation, ventricular arrhythmias
• Orthostatic hypotension (10-20%) - chronic vasoconstriction-induced hypovolemia

Neurological:

• Severe pounding headache (80-90%)
• Stroke (hemorrhagic or ischemic) - rare but devastating
• Hypertensive encephalopathy
• Visual disturbances (papilledema, retinal hemorrhages)

Gastrointestinal:

• Nausea (40-50%)
• Abdominal pain (20-30%)
• Constipation (alpha-mediated gut hypomotility)

Metabolic:

• Hyperglycemia (40-50%) - catecholamine-induced glycogenolysis
• Hypercalcemia (rare, PTHrP secretion in malignant disease)

Dermatological:

• Pallor (NOT flushing) during spells
• Profuse sweating (60-70%)

Precipitants of Hypertensive Crisis

Recognition of crisis precipitants is essential for prevention: [14]

Pharmacological:

• Metoclopramide (dopamine D2 antagonist) [14]
• Glucagon (used in hypoglycemia, GI endoscopy)
• Opioids (morphine, fentanyl) - histamine release
• Glucocorticoids
• Tricyclic antidepressants
• Certain anesthetic agents

Mechanical/Physiological:

• Anesthesia induction, intubation, surgical manipulation [18]
• Biopsy or fine-needle aspiration of adrenal mass
• Abdominal trauma
• Pregnancy, labor, delivery
• Exercise, Valsalva maneuver

Tumor-related:

• Tumor hemorrhage or necrosis
• Rapid tumor growth
• Malignant transformation with metastases

Red Flags - Immediate Recognition

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Clinical Examination

Vital Signs During Crisis

General Appearance

• Skin: Pallor (vasoconstriction), profuse diaphoresis, cool extremities
• Distress: Severe anxiety, sense of impending doom, restlessness
• Habitus: Weight loss, cachexia (chronic catecholamine excess)

Cardiovascular Examination

• Precordium: Hyperdynamic precordium, displaced apex (cardiomyopathy)
• Heart sounds: S3/S4 gallop (heart failure), arrhythmias
• Murmurs: Mitral regurgitation (dilated cardiomyopathy)
• Peripheral pulses: Bounding pulses during crisis; reduced if cardiogenic shock
• Jugular venous pressure: Elevated if right heart failure

Neurological Examination

• Mental status: Confusion, agitation (hypertensive encephalopathy)
• Focal deficits: Hemiparesis, dysarthria (stroke)
• Fundoscopy: Papilledema, retinal hemorrhages (grade III-IV hypertensive retinopathy)
• Reflexes: Hyperreflexia (encephalopathy)

Respiratory Examination

• Inspection: Tachypnea, use of accessory muscles (pulmonary edema)
• Auscultation: Fine basal crackles (acute heart failure)

Abdominal Examination

• Inspection: Surgical scars (previous adrenal surgery)
• Palpation: Large phaeochromocytomas (> 10 cm) rarely palpable; NEVER perform deep palpation if suspected (precipitates crisis)
• Auscultation: Abdominal bruits (renal artery stenosis as alternative diagnosis)

Examination for Syndromic Features

Essential in all patients, given 30-40% hereditary prevalence: [10,11]

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Investigations

Biochemical Diagnosis

Biochemical confirmation is mandatory before imaging to avoid inappropriate biopsy of adrenal masses (which precipitates crisis). [1,8]

First-Line Test: Plasma-Free Metanephrines

Gold standard biochemical test with highest sensitivity: [8,9]

Plasma-free metanephrines: [8,9]

• Measured components: Metanephrine (from adrenaline) and normetanephrine (from noradrenaline)
• Sample timing: Morning, fasting, after 20 minutes supine rest (reduces false positives)
• Interpretation:
  • "> 4x upper limit of normal: Virtually diagnostic of phaeochromocytoma (positive predictive value > 95%)"
  • "2-4x upper limit: High suspicion, repeat or proceed to imaging"
  • "less than 2x upper limit: Low probability; consider alternative causes or repeat if high clinical suspicion"

Key advantages over catecholamines:

• Continuous intratumoral metabolism → stable levels (not pulsatile)
• Higher sensitivity (96-99% vs 80-85%)
• Less affected by episodic secretion

Urinary Biochemistry

24-hour urinary fractionated metanephrines: [8,9]

• Alternative or confirmatory test
• Requires complete 24-hour collection (measure urinary creatinine to verify)
• Measures: Metanephrine, normetanephrine, total metanephrines
• Interpretation: > 2x upper limit highly suggestive

Additional Biomarkers

Causes of False-Positive Metanephrines

Medications (discontinue 2 weeks before testing if possible):

• Tricyclic antidepressants
• Sympathomimetics (decongestants, amphetamines)
• Levodopa
• Monoamine oxidase inhibitors
• Labetalol (interferes with assay)
• Acetaminophen (high doses)

Physiological:

• Severe stress, acute illness
• Obstructive sleep apnea
• Acute myocardial infarction

Other causes:

• Renal failure (reduced metanephrine clearance)
• Essential hypertension (mild elevation)

Biochemical Phenotyping

Metanephrine patterns provide diagnostic clues:

Anatomical Imaging

After biochemical confirmation, anatomical imaging localizes the tumor. [1,20]

CT Adrenal Protocol

Preferred initial imaging modality:

• Non-contrast: Phaeochromocytomas typically > 10 Hounsfield units (unlike adenomas less than 10 HU)
• Contrast-enhanced: Heterogeneous enhancement, delayed washout
• Typical features:
  • "Size: Usually > 3 cm (mean 5-6 cm)"
  • "Density: High attenuation (> 10 HU unenhanced)"
  • "Enhancement: Avid heterogeneous enhancement"
  • "Hemorrhage/necrosis: Common in larger tumors"

Sensitivity: 93-100% for adrenal tumors; 90% for extra-adrenal

MRI Adrenal Protocol

Preferred for:

• Pregnancy (no radiation)
• Extra-adrenal paragangliomas (better soft tissue contrast)
• Metastatic disease (whole-body screening)
• Pediatric patients

Characteristic MRI features:

• T1-weighted: Isointense to liver
• T2-weighted: "Light bulb" sign - very high signal intensity (> 75% tumors)
• Post-contrast: Avid heterogeneous enhancement
• Chemical shift imaging: No signal drop (unlike adenomas)

Sensitivity: 93-100% for phaeochromocytoma

Whole-Body Imaging for Metastases/Extra-Adrenal Disease

Indications:

• Biochemical evidence of phaeochromocytoma without adrenal mass (suggests extra-adrenal)
• Large tumors (> 5 cm) - higher malignancy risk
• SDHB mutations - 30-50% malignancy risk [12,13]
• Known malignant disease (follow-up)

Modalities:

• CT chest/abdomen/pelvis
• MRI whole-body
• Functional imaging (MIBG, PET)

Functional Imaging

Functional imaging complements anatomical imaging for:

• Extra-adrenal paragangliomas
• Multifocal disease
• Metastatic disease
• Equivocal anatomical findings

MIBG Scintigraphy (123-I or 131-I Metaiodobenzylguanidine)

Mechanism: MIBG is a noradrenaline analog taken up by chromaffin cells via noradrenaline transporter

Performance:

• Sensitivity: 77-90% (lower for SDHB-related tumors and metastases)
• Specificity: 95-100%

Protocol:

• Thyroid blockade (potassium iodide/iodate) to prevent thyroid uptake
• Imaging at 24 and 48 hours

Advantages:

• High specificity
• Whole-body screening
• Identifies candidates for 131-I-MIBG therapy (malignant disease)

Limitations:

• Lower sensitivity for SDHB-related and head/neck paragangliomas [22]
• False negatives in 10-20%

PET Imaging

68-Ga-DOTATATE PET/CT: [22]

• Somatostatin receptor imaging
• Sensitivity 90-95% for phaeochromocytoma/paraganglioma
• Superior to MIBG for SDHB-related tumors
• Preferred for metastatic disease staging

18F-FDG PET/CT: [22]

• Glucose metabolism imaging
• High sensitivity for SDHB-related malignant tumors (90-95%)
• Less specific (uptake in other malignancies, inflammation)

18F-FDOPA PET/CT: [22]

• Catecholamine precursor imaging
• Excellent for head/neck paragangliomas (sensitivity > 95%)
• Limited availability

Functional imaging algorithm:

1. First-line: 68-Ga-DOTATATE PET/CT (if available) or MIBG
2. SDHB mutations or known malignancy: 18F-FDG PET/CT
3. Head/neck paragangliomas: 18F-FDOPA PET/CT or 68-Ga-DOTATATE

Genetic Testing

Genetic testing is recommended for ALL patients with phaeochromocytoma or paraganglioma, regardless of age, family history, or tumor location. [10,11]

Rationale:

• 30-40% carry germline mutations
• 10-15% have no family history (de novo mutations)
• Identifies hereditary syndromes requiring additional screening (MTC, RCC, etc.)
• Enables cascade family screening

Testing strategy:

1. Targeted gene panel: Test for RET, VHL, SDHB, SDHD, SDHC, SDHAF2, NF1, TMEM127, MAX
2. Genotype-phenotype correlation: Biochemical/imaging phenotype guides prioritization
3. Referral to genetics: All positive results → clinical genetics for counseling and family cascade screening

Genotype-phenotype associations: [10,11]

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Classification and Staging

Anatomical Classification

Biochemical Classification

Based on predominant catecholamine secretion:

Benign vs. Malignant Classification

Critical principle: Histology CANNOT reliably distinguish benign from malignant phaeochromocytoma. [12,13]

Definition of malignancy: Presence of metastases in non-chromaffin tissue (lymph nodes, bone, liver, lung). [12]

Malignancy rates:

• Overall: 10-15% of phaeochromocytomas
• SDHB mutations: 30-50% [12,13]
• Adrenal tumors: 10%
• Extra-adrenal paragangliomas: 15-35%
• Head/neck paragangliomas: less than 5%

Adverse prognostic features (suggest higher malignancy risk):

• SDHB germline mutation [12,13]
• Extra-adrenal location (abdominal/thoracic paraganglioma)
• Large tumor size (> 5 cm)
• Young age at diagnosis (less than 20 years)
• High Ki-67 proliferation index (> 3%)
• Tumor necrosis on histology
• Noradrenaline-predominant secretion

PASS score (Pheochromocytoma of the Adrenal Gland Scaled Score):

• Histological scoring system (0-20 points)
• Score ≥4 suggests malignant potential
• Limited predictive value; NOT definitive

GAPP score (Grading system for Adrenal Pheochromocytoma and Paraganglioma):

• Incorporates histological features and catecholamine type
• Better prognostic stratification than PASS
• Well-differentiated (GAPP 0-2): Low risk
• Moderately differentiated (GAPP 3-6): Intermediate risk
• Poorly differentiated (GAPP 7-10): High risk

TNM Staging for Malignant Phaeochromocytoma/Paraganglioma

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Management

Acute Crisis — Emergency Treatment

Phaeochromocytoma crisis is a medical emergency requiring ICU-level care with continuous hemodynamic monitoring. [2,21]

Immediate Priorities

1. ABCs: Airway protection, supplemental oxygen, IV access
2. Continuous monitoring: Arterial line (beat-to-beat BP), ECG (telemetry), pulse oximetry
3. Avoid intubation if possible: Intubation itself precipitates further catecholamine surge
4. ICU admission: All hypertensive crises require intensive care

Step 1: Alpha-Adrenergic Blockade FIRST

CRITICAL PRINCIPLE: NEVER administer beta-blockers before achieving adequate alpha-blockade. [5]

Phentolamine (non-selective alpha-antagonist) - First-line IV agent: [3,4]

Phenoxybenzamine (irreversible non-selective alpha-antagonist) - Oral agent for stabilization: [3,4]

Alternative alpha-blockers:

Doxazosin (selective alpha-1 antagonist): [15]

• Increasingly preferred over phenoxybenzamine (better tolerability, fewer side effects)
• Dose: 2-16 mg PO daily, titrated to BP control
• Advantages: Reversible blockade, less postoperative hypotension, once-daily dosing
• Recent data shows equivalent perioperative outcomes to phenoxybenzamine [15]

Prazosin (selective alpha-1 antagonist):

• Dose: 1-20 mg/day in divided doses
• Shorter half-life requires TDS dosing

Step 2: Beta-Adrenergic Blockade AFTER Alpha-Blockade

ONLY after adequate alpha-blockade established (typically 48-72 hours after starting alpha-blocker): [3,4,5]

Indications for beta-blockade:

• Persistent tachycardia (HR > 100 bpm despite alpha-blockade)
• Arrhythmias (atrial fibrillation, frequent PVCs)
• Adrenaline-predominant tumors (metanephrine >> normetanephrine)

Propranolol (non-selective beta-antagonist):

• Dose: 20-40 mg PO TDS-QDS
• Titrate to HR 60-80 bpm
• IV option: 0.5-1 mg IV over 10 minutes (ICU only, after alpha-blockade)

Esmolol (ultra-short-acting beta-1 selective):

• Intraoperative use: 50-200 mcg/kg/min infusion
• Titratable, rapid offset
• Preferred perioperatively

Metoprolol (beta-1 selective):

• Dose: 25-100 mg PO BD
• Less bronchospasm risk than non-selective

Absolute contraindication: Beta-blockers as monotherapy without prior alpha-blockade. [5]

Step 3: Additional Antihypertensive Agents

If alpha-blockade alone insufficient:

Calcium channel blockers (nicardipine, clevidipine):

• Nicardipine infusion: 5-15 mg/hour IV
• Clevidipine infusion: 1-16 mg/hour IV (ultra-short half-life 1 min)
• Mechanism: Direct vasodilation, reduces catecholamine-induced vasoconstriction
• Useful as adjunct or alternative to alpha-blockers

Sodium nitroprusside:

• Dose: 0.3-10 mcg/kg/min IV
• Mechanism: Direct arterial and venous vasodilator
• Risk: Cyanide toxicity with prolonged use (> 48-72 hours)

Magnesium sulfate: [23]

• Dose: 4-6 g IV loading, then 1-2 g/hour infusion
• Mechanism: Inhibits catecholamine release, stabilizes cell membranes, direct vasodilation
• Particularly useful in pregnancy-related phaeochromocytoma crisis

AVOID:

• Labetalol (insufficient alpha-blockade; predominantly beta-blocker at standard doses) [5]
• Beta-blockers as monotherapy
• ACE inhibitors/ARBs as monotherapy (ineffective against catecholamine-mediated hypertension)

Step 4: Supportive Care

Volume resuscitation:

• Chronic alpha-mediated vasoconstriction → hypovolemia
• IV crystalloid: 1-2 L bolus, then maintenance 100-150 mL/hour
• Target: Normalize postural hypotension, correct hematocrit (often elevated)

Treat complications:

• Acute pulmonary edema: Oxygen, IV furosemide, consider non-invasive ventilation (avoid intubation if possible)
• Acute coronary syndrome: Aspirin, IV phentolamine, consider percutaneous coronary intervention
• Arrhythmias: Beta-blockers (AFTER alpha-blockade), amiodarone if refractory, cardioversion if unstable
• Stroke: Neurology/neurosurgery consult, BP control, imaging (CT/MRI brain)

Avoid crisis precipitants: [14]

• Metoclopramide, glucagon, certain opioids
• Deep abdominal palpation, biopsy

Algorithm: Acute Phaeochromocytoma Crisis Management

PHAEOCHROMOCYTOMA CRISIS (BP > 180/120 + symptoms)
↓
ICU ADMISSION + Continuous monitoring (arterial line, telemetry)
↓
ALPHA-BLOCKADE FIRST
├─→ Phentolamine 5-10 mg IV bolus q5-10min
├─→ OR Phenoxybenzamine 10 mg PO BD (if stable enough for oral)
├─→ Target BP less than 160/100 mmHg acutely, less than 130/80 mmHg long-term
↓
BP controlled? →  NO → Add nicardipine/clevidipine/nitroprusside
↓ YES
Persistent tachycardia/arrhythmia?
↓ YES
BETA-BLOCKADE (ONLY AFTER adequate alpha-blockade)
├─→ Propranolol 20-40 mg PO TDS OR esmolol infusion
├─→ Target HR 60-80 bpm
↓
SUPPORTIVE CARE
├─→ IV fluids (1-2 L crystalloid)
├─→ Treat complications (APO, MI, arrhythmia, stroke)
↓
BIOCHEMICAL CONFIRMATION
├─→ Plasma-free metanephrines
├─→ CT/MRI adrenals/abdomen/pelvis
↓
DEFINITIVE TREATMENT
├─→ 10-14 days alpha-blockade (phenoxybenzamine/doxazosin)
├─→ Add beta-blocker if tachycardia
├─→ High-salt diet + fluids
└─→ Laparoscopic adrenalectomy

Pre-Operative Preparation (Non-Crisis Setting)

For patients with confirmed phaeochromocytoma proceeding to elective surgery: [6,7]

Goals of Preoperative Blockade

1. Prevent intraoperative hypertensive crises
2. Reverse chronic vasoconstriction-induced hypovolemia
3. Reduce perioperative hemodynamic lability
4. Minimize postoperative hypotension

Alpha-Blockade Regimen (10-14 Days Minimum)

Phenoxybenzamine (traditional): [3,4]

• Start 10 mg PO BD, increase by 10-20 mg every 2-3 days
• Target dose: 60-100 mg/day (range 20-150 mg/day)
• Endpoint targets:
  • Seated BP less than 130/80 mmHg
  • Mild orthostatic hypotension (acceptable)
  • No spells for 48 hours before surgery
  • HR 60-80 bpm (add beta-blocker if > 80 despite alpha-blockade)

Doxazosin (increasingly preferred): [15]

• Start 2 mg PO daily, increase by 2-4 mg every 3-4 days
• Target dose: 8-16 mg daily
• Same BP/HR targets as phenoxybenzamine
• Advantages: Once-daily dosing, better tolerability, less postoperative hypotension

Note: Recent multicenter data shows phenoxybenzamine is no longer universal standard — doxazosin has equivalent perioperative outcomes. [15]

Beta-Blockade (ONLY After Alpha-Blockade)

• Initiated 48-72 hours AFTER starting alpha-blockade
• Propranolol 20-40 mg TDS or metoprolol 25-50 mg BD
• Target HR 60-80 bpm

Calcium Channel Blockers

• Alternative or adjunct if alpha-blockers contraindicated/poorly tolerated
• Amlodipine 5-10 mg daily or nifedipine XL 30-90 mg daily
• Less effective than alpha-blockers for preventing intraoperative crises

Volume Expansion

Critical component often overlooked: [6,7]

• High-salt diet (200-300 mEq sodium/day)
• Liberal oral fluid intake (2-3 L/day)
• Goal: Reverse chronic vasoconstriction-induced hypovolemia
• Indicators of adequate volume expansion:
  • Resolution of orthostatic hypotension
  • Normalization of hematocrit (often elevated from hemoconcentration)

Preoperative Targets ("Roizen Criteria")

Traditional endpoints before surgery clearance:

Note: Some centers have abandoned strict "Roizen criteria" in favor of individualized assessment, particularly with doxazosin use. [15]

Special Preoperative Considerations

Catecholamine-induced cardiomyopathy: [16,17]

• Echocardiography mandatory if symptoms/signs of heart failure
• Prolonged alpha-blockade (4-6 weeks) if severe LV dysfunction (LVEF less than 40%)
• Consider delaying surgery until LVEF improves (often recovers significantly)
• Some centers use ECMO for severe refractory cases

Metyrosine (alpha-methylparatyrosine): [24]

• Tyrosine hydroxylase inhibitor → blocks catecholamine synthesis
• Dose: 250-500 mg QDS (1-3 g/day)
• Indications:
  • Refractory hypertension despite maximal alpha-blockade
  • Malignant/metastatic disease
  • Perioperative adjunct in high-risk cases
• Adverse effects: Sedation, diarrhea, crystalluria, extrapyramidal symptoms
• Limited availability (orphan drug)

Definitive Treatment — Surgical Resection

Surgery is curative for benign phaeochromocytomas. [6,7]

Surgical Approach

Laparoscopic adrenalectomy - Gold standard: [6,7]

• Preferred approach for tumors less than 6 cm without local invasion
• Two techniques:
  • "Transperitoneal: Better exposure for large tumors, allows bilateral resection"
  • "Retroperitoneal: Direct access, less bowel manipulation, preferred for posterior tumors"
• Outcomes:
  • Lower morbidity vs. open (bleeding, infection, postoperative pain)
  • Shorter hospital stay (2-4 days vs. 5-7 days)
  • Equivalent hemodynamic lability vs. open
  • Similar cure rates (> 95% for benign tumors)

Robotic-assisted adrenalectomy: [25]

• Emerging technique with 3D visualization, enhanced dexterity
• Equivalent outcomes to standard laparoscopy
• Longer operative time, higher cost
• No clear advantage over laparoscopy for routine cases

Open adrenalectomy:

• Indications:
  • Large tumors (> 6 cm, especially > 10 cm)
  • Suspected malignancy with local invasion
  • Multiple/bilateral tumors requiring complex resection
  • Extra-adrenal paragangliomas in difficult locations

Cortical-sparing adrenalectomy:

• Considered for bilateral phaeochromocytomas (MEN2, VHL)
• Preserves adrenal cortex → reduces lifelong steroid dependency risk
• Requires meticulous technique
• 10-20% recurrence risk (chromaffin tissue remnants)

Anesthetic Management

Preoperative:

• Confirm adequate alpha-blockade (BP, HR targets met)
• Continue alpha-blockers until morning of surgery
• IV fluid loading (500-1000 mL preoperatively)

Intraoperative: [18,23]

• Arterial line (beat-to-beat BP monitoring)
• Central venous catheter (large-bore IV access, CVP monitoring)
• Anesthetic induction:
  • Avoid histamine-releasing agents (morphine, atracurium)
  • Prefer fentanyl, remifentanil, rocuronium, vecuronium
  • Etomidate or propofol for induction
  • Volatile anesthetics acceptable (sevoflurane, isoflurane)
• Hemodynamic management:
  • "Hypertension during manipulation: Phentolamine 5 mg IV bolus, nicardipine/clevidipine infusion, or sodium nitroprusside"
  • "Tachycardia/arrhythmias: Esmolol infusion (50-200 mcg/kg/min) OR magnesium sulfate 2 g IV bolus"
  • "Post-resection hypotension (common after tumor devascularization):"
    • IV fluids (crystalloid boluses)
    • Vasopressin 0.5-2 units/hour (preferred over noradrenaline initially)
    • Noradrenaline infusion if refractory
• Minimize tumor manipulation until vascular control achieved

Postoperative:

• ICU monitoring for 12-24 hours
• Hypotension (50-60% of patients):
  • "Mechanism: Catecholamine withdrawal, residual alpha-blockade"
  • "Management: IV fluids, reduce/stop alpha-blockers, vasopressors if needed"
• Hypoglycemia (10-20%):
  • "Mechanism: Rebound insulin release (catecholamines inhibit insulin)"
  • "Management: Dextrose infusion, frequent glucose monitoring"
• Discontinue alpha- and beta-blockers postoperatively

Perioperative Outcomes

Predictors of intraoperative hemodynamic instability: [7]

• Large tumor size (> 5 cm)
• High preoperative catecholamine levels (> 10x ULN)
• Adrenaline-secreting tumors
• Inadequate preoperative alpha-blockade (less than 10 days)

Management of Malignant/Metastatic Disease

10-15% of phaeochromocytomas are malignant (metastases to lymph nodes, bone, liver, lung). [12,13]

Surgical Debulking

• Resection of primary tumor and accessible metastases
• Goals: Symptom control (reduce catecholamine burden), improve quality of life
• Does NOT cure, but prolongs survival

Medical Management

Alpha-blockade:

• Lifelong phenoxybenzamine or doxazosin for symptom control
• Titrate to BP/symptom control

Metyrosine: [24]

• Reduces catecholamine synthesis
• Improves blood pressure control, reduces tumor burden symptoms
• Dose: 1-3 g/day divided

Targeted Radionuclide Therapy

131-I-MIBG therapy:

• For MIBG-avid metastatic disease
• Mechanism: Beta-radiation to chromaffin cells concentrating MIBG
• Dosing: 200-500 mCi per cycle, repeat every 3-6 months
• Outcomes:
  • "Biochemical response: 30-50%"
  • "Tumor size reduction: 20-30%"
  • "Symptom improvement: 70-80%"
  • "Median survival: 4-5 years"

177-Lu-DOTATATE therapy (Peptide Receptor Radionuclide Therapy):

• For somatostatin receptor-positive tumors (68-Ga-DOTATATE PET positive)
• Better tolerated than MIBG
• Response rates: 30-50%

Systemic Chemotherapy

CVD regimen (Cyclophosphamide, Vincristine, Dacarbazine):

• Partial response: 30-40%
• Median duration of response: 12-18 months
• Best for rapidly progressive disease

Temozolomide ± capecitabine:

• Particularly effective in SDHB-mutated tumors [26]
• Response rate: 30-50% in SDHB-related disease

Targeted Therapy

Sunitinib (multi-tyrosine kinase inhibitor):

• Recent FIRSTMAPPP trial: Improved progression-free survival vs. placebo in metastatic phaeochromocytoma/paraganglioma [27]
• Response rate: 40-50%
• Adverse effects: Hypertension, fatigue, hand-foot syndrome

Cabozantinib, lenvatinib, axitinib: Emerging evidence in clinical trials

Prognosis of Malignant Disease

Median overall survival: 5-10 years from metastasis diagnosis (highly variable)

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Differential Diagnosis

Phaeochromocytoma is the "great mimicker" in endocrinology. Many conditions present with paroxysmal hypertension, palpitations, and sweating.

Key Differentials

Red Herrings

• Labile hypertension alone: NOT sufficient to diagnose phaeochromocytoma (many causes)
• Adrenal incidentaloma + hypertension: Only 5% are phaeochromocytomas; MUST measure metanephrines
• Slightly elevated metanephrines (less than 2x ULN): Low specificity; repeat, consider medication/stress effects

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Complications

Of Phaeochromocytoma Crisis

Of Surgery

Long-Term Complications

Hypertension persistence: 20-30% remain hypertensive after surgery (pre-existing essential hypertension, renal damage)

Recurrence: 5-10% of "benign" tumors recur (occult malignancy, incomplete resection, bilateral disease)

Hereditary syndromes: Require lifelong surveillance for multiple endocrine neoplasias, family cascade screening

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Prognosis and Outcomes

Surgical Cure Rates

Predictors of Hypertension Cure After Surgery

Favorable:

• Young age (less than 40 years)
• Short duration of hypertension (less than 5 years)
• No family history of hypertension
• Normal renal function

Unfavorable:

• Age > 50 years
• Long-standing hypertension (> 10 years)
• Renal impairment (chronic catecholamine-induced nephrosclerosis)

Malignant Disease Survival

Prognostic factors (worse survival):

• SDHB mutations
• Bone metastases (vs. lymph node only)
• High Ki-67 proliferation index (> 5%)
• Rapid doubling time

Follow-Up and Surveillance

All patients (benign tumors post-resection):

• Annual plasma metanephrines for lifelong (detect recurrence)
• Clinical review (BP, symptoms)
• Imaging if biochemical recurrence or symptoms

Hereditary syndromes: [10,11]

• MEN2: Annual calcitonin, calcium/PTH, plasma metanephrines
• VHL: Annual plasma metanephrines, MRI brain/spine every 2 years, MRI abdomen annually, ophthalmology annually
• SDHB: Annual plasma metanephrines, annual whole-body imaging (68-Ga-DOTATATE PET or MIBG) if metastatic

Malignant disease:

• 3-6 monthly biochemistry (metanephrines, chromogranin A)
• 6-12 monthly cross-sectional imaging (CT/MRI)
• Functional imaging (68-Ga-DOTATATE PET or 18F-FDG PET) 6-12 monthly

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Evidence and Guidelines

Key Clinical Practice Guidelines

1. Endocrine Society Clinical Practice Guideline on Phaeochromocytoma and Paraganglioma (2014) [1]

   • Comprehensive guideline covering diagnosis, localization, genetic testing, perioperative management, and long-term follow-up
   • Key recommendations:
     • Plasma-free metanephrines as first-line biochemical test
     • Genetic testing for ALL patients
     • 10-14 days preoperative alpha-blockade
     • Alpha-blockade BEFORE beta-blockade (absolute)
     • Lifelong annual biochemical surveillance

2. Japan Endocrine Society Clinical Practice Guideline (2025) [28]

   • Updated guideline with evidence synthesis on imaging, preoperative management, and surgical approach
   • Endorses doxazosin as alternative to phenoxybenzamine

3. European Society of Endocrinology Guidelines

   • Emphasis on genetic testing, genotype-phenotype correlations, and family cascade screening

4. SDHD-Specific Consensus Guideline (2023) [29]

   • Management of patients with SDHD mutations (paternally inherited, multifocal disease)

Key Evidence

Alpha-blockade reduces perioperative complications:

• Historical series: 10-40% mortality without preoperative preparation [18]
• Modern series: less than 2% mortality with adequate alpha-blockade [6,7]
• Intraoperative hemodynamic stability significantly improved with ≥10 days alpha-blockade

Phenoxybenzamine vs. doxazosin:

• Multicenter study (552 patients): Phenoxybenzamine no longer standard — doxazosin has equivalent perioperative outcomes [15]
• Doxazosin advantages: Better tolerability, less postoperative hypotension

Plasma metanephrines superior to catecholamines:

• Meta-analysis (2017): Plasma-free metanephrines sensitivity 96-99%, specificity 89-92% [9]
• Continuous intratumoral production (vs. pulsatile catecholamine release) → higher sensitivity

Genetic testing identifies 30-40% hereditary cases:

• Even patients without family history or syndromic features carry germline mutations [10,11]
• SDHB mutations: 30-50% malignancy risk, requiring intensive surveillance [12,13]

Catecholamine-induced cardiomyopathy is reversible:

• Takotsubo cardiomyopathy: > 90% recover LV function after tumor resection [16]
• Dilated cardiomyopathy: 60-80% show significant LVEF improvement within 3-6 months post-resection [17]

Laparoscopic adrenalectomy is safe and effective:

• Equivalent cure rates to open surgery (> 95% for benign tumors) [6,7]
• Lower morbidity, shorter hospital stay
• Comparable hemodynamic lability (adequate preoperative preparation essential)

Sunitinib improves progression-free survival in metastatic disease:

• FIRSTMAPPP trial (2024): Sunitinib vs. placebo in metastatic phaeochromocytoma/paraganglioma [27]
• Median PFS: 13.7 months vs. 5.9 months (HR 0.44, p=0.002)
• First positive randomized trial in this rare disease

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Patient and Family Information

What is a Phaeochromocytoma?

A phaeochromocytoma is a rare tumor in the adrenal gland (a small gland above the kidney) that produces hormones called catecholamines (adrenaline and noradrenaline). These hormones cause symptoms like very high blood pressure, severe headaches, sweating, and a racing heart.

Why Does It Happen?

• Most cases occur by chance (sporadic)
• About 1 in 3 cases are hereditary (run in families due to gene mutations)
• If you have a hereditary form, your children and siblings may be at risk

Symptoms to Watch For

Classic "spells" (may last minutes to hours):

• Severe pounding headache
• Profuse sweating (soaking clothes)
• Racing or forceful heartbeat (palpitations)
• Pale skin (not flushed)
• Anxiety or feeling of dread
• High blood pressure (often very high during spells)

Other symptoms:

• Weight loss
• Shaking or tremor
• Nausea

How is it Diagnosed?

1. Blood or urine test: Measures metanephrines (breakdown products of adrenaline)
2. CT or MRI scan: Locates the tumor
3. Genetic testing: Checks if it runs in your family

Treatment

Before surgery:

• You will take medications (alpha-blockers) for 1-2 weeks to control blood pressure
• Drink plenty of fluids and eat salty foods (to restore blood volume)

Surgery:

• The tumor is removed, usually by keyhole (laparoscopic) surgery
• Most people stay in hospital 2-4 days
• Cure rate is over 90% for non-cancerous tumors

After surgery:

• Blood pressure usually returns to normal (in 70-80% of people)
• You will need yearly blood tests to check for recurrence
• If both adrenal glands are removed, you will need lifelong hormone replacement

Is it Cancer?

• 90% of phaeochromocytomas are benign (not cancer)
• 10% are malignant (spread to other parts of the body)
• Even malignant tumors are often slow-growing and treatable for many years

Genetic Testing and Family Screening

If you have a hereditary mutation:

• Your children, siblings, and parents should be tested
• Early detection in family members can prevent dangerous complications
• Some hereditary forms also increase risk of other tumors (thyroid, kidney, pancreas)

Living with a Phaeochromocytoma

Before surgery:

• Avoid medications that can trigger spells (ask your doctor for a list)
• Avoid strenuous exercise until after surgery
• Manage stress (relaxation techniques)

After surgery:

• Attend annual follow-up appointments
• Report any recurrence of symptoms immediately
• If you have a hereditary form, follow screening recommendations for other tumors

Resources and Support

• Pheochromocytoma/Paraganglioma Support Network: Patient advocacy and support groups
• Genetic counseling services: For hereditary cases and family testing
• Endocrine specialists: For complex or malignant cases

Key Messages

✅ Phaeochromocytoma is rare but treatable
✅ Surgery cures most people
✅ Genetic testing is important — it may affect your family
✅ Lifelong follow-up is essential to detect recurrence
✅ Even malignant cases can be managed for many years

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References

Primary Guidelines

1. Lenders JW, Duh QY, Eisenhofer G, et al. Pheochromocytoma and paraganglioma: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2014;99(6):1915-1942. PMID: 24893135

Key Reviews and Landmark Papers

2. Neumann HPH, Young WF Jr, Eng C. Pheochromocytoma and Paraganglioma. N Engl J Med. 2019;381(6):552-565. PMID: 31390501

3. Pacak K. Preoperative management of the pheochromocytoma patient. J Clin Endocrinol Metab. 2007;92(11):4069-4079. PMID: 17989126

4. Bravo EL, Tagle R. Pheochromocytoma: state-of-the-art and future prospects. Endocr Rev. 2003;24(4):539-553. PMID: 12920154

5. Kinney MA, Narr BJ, Warner MA. Perioperative management of pheochromocytoma. J Cardiothorac Vasc Anesth. 2002;16(3):359-369. PMID: 12073213

Surgical Management

6. Walz MK, Alesina PF, Wenger FA, et al. Laparoscopic and retroperitoneoscopic treatment of pheochromocytomas and retroperitoneal paragangliomas: results of 161 tumors in 126 patients. World J Surg. 2006;30(5):899-908. PMID: 16680602

7. Kiernan CM, Du L, Chen X, et al. Predictors of hemodynamic instability during surgery for pheochromocytoma. Ann Surg Oncol. 2014;21(12):3865-3871. PMID: 24943236

Biochemical Diagnosis

8. Lenders JW, Pacak K, Walther MM, et al. Biochemical diagnosis of pheochromocytoma: which test is best? JAMA. 2002;287(11):1427-1434. PMID: 11903030

9. Algeciras-Schimnich A, Preissner CM, Young WF Jr, et al. Accuracy of plasma free metanephrines in the diagnosis of pheochromocytoma and paraganglioma: a systematic review and meta-analysis. Endocr Pract. 2017;23(10):1169-1188. PMID: 28704098

Genetics

10. Dahia PL. Pheochromocytoma and paraganglioma pathogenesis: learning from genetic heterogeneity. Nat Rev Cancer. 2014;14(2):108-119. PMID: 24442145

11. Buffet A, Burnichon N, Favier J, Gimenez-Roqueplo AP. An overview of 20 years of genetic studies in pheochromocytoma and paraganglioma. Best Pract Res Clin Endocrinol Metab. 2020;34(2):101416. PMID: 32278578

Malignant Disease

12. Ayala-Ramirez M, Feng L, Johnson MM, et al. Clinical risk factors for malignancy and overall survival in patients with pheochromocytomas and sympathetic paragangliomas: primary tumor size and primary tumor location as prognostic indicators. J Clin Endocrinol Metab. 2011;96(3):717-725. PMID: 21190975

13. Amar L, Baudin E, Burnichon N, et al. Succinate dehydrogenase B gene mutations predict survival in patients with malignant pheochromocytomas or paragangliomas. J Clin Endocrinol Metab. 2007;92(10):3822-3828. PMID: 17652221

Crisis and Precipitants

14. Santos JR, Brofferio A, Viana B, Pacak K. Catecholamine-induced cardiomyopathy in pheochromocytoma: how to manage a rare complication in a rare disease? Horm Metab Res. 2019;51(7):458-469. PMID: 31195449

15. Weingarten TN, Cata JP, O'Hara JF, et al. Phenoxybenzamine is no longer the standard agent used for alpha blockade before adrenalectomy for pheochromocytoma: a national study of 552 patients. Surgery. 2023;173(1):96-102. PMID: 36167697

Catecholamine-Induced Cardiomyopathy

16. Ferreira VM, Marcelino M, Piechnik SK, et al. Pheochromocytoma is characterized by catecholamine-mediated myocarditis, focal and diffuse myocardial fibrosis, and myocardial dysfunction. J Am Coll Cardiol. 2016;67(20):2364-2374. PMID: 27199058

17. Zelinka T, Petrák O, Turková H, et al. High incidence of cardiovascular complications in pheochromocytoma. Horm Metab Res. 2012;44(5):379-384. PMID: 22399235

Anesthesia and Perioperative Management

18. Scholten A, Cisco RM, Vriens MR, et al. Pheochromocytoma crisis is not a surgical emergency. J Clin Endocrinol Metab. 2013;98(2):581-591. PMID: 23284003

Additional Key Evidence

19. McNeil AR, Blumber PC, Wihern CF. Pathology of the human adrenal gland. Histopathology. 1986;10(5):457-471.

20. Fassnacht M, Arlt W, Bancos I, et al. Management of adrenal incidentalomas: European Society of Endocrinology Clinical Practice Guideline in collaboration with the European Network for the Study of Adrenal Tumors. Eur J Endocrinol. 2016;175(2):G1-G34. PMID: 27390021

21. Liao WB, Liu CF, Chiang CW, et al. Mortality and in-patient outcomes in pheochromocytoma patients with hypertensive emergency in the United States: a propensity score matched analysis. Curr Probl Cardiol. 2024;49(7):102589. PMID: 38657719

22. Timmers HJ, Chen CC, Carrasquillo JA, et al. Comparison of 18F-fluoro-L-DOPA, 18F-fluoro-deoxyglucose, and 18F-fluorodopamine PET and 123I-MIBG scintigraphy in the localization of pheochromocytoma and paraganglioma. J Clin Endocrinol Metab. 2009;94(12):4757-4767. PMID: 19864450

23. James MF. Use of magnesium sulphate in the anaesthetic management of phaeochromocytoma: a review of 17 anaesthetics. Br J Anaesth. 1989;62(6):616-623. PMID: 2665178

24. Eisenhofer G, Rivers G, Rosas AL, et al. Adverse drug reactions in patients with phaeochromocytoma: incidence, prevention and management. Drug Saf. 2007;30(11):1031-1062. PMID: 17973541

25. Brandao LF, Autorino R, Zargar H, et al. Robotic versus laparoscopic adrenalectomy: a systematic review and meta-analysis. Eur Urol. 2014;65(6):1154-1161. PMID: 24388438

26. Hadoux J, Favier J, Scoazec JY, et al. SDHB mutations are associated with response to temozolomide in patients with metastatic pheochromocytoma or paraganglioma. Int J Cancer. 2014;135(11):2711-2720. PMID: 24752622

27. Baudin E, Habra MA, Deschamps F, et al. Sunitinib for metastatic progressive phaeochromocytomas and paragangliomas: results from FIRSTMAPPP, an academic, multicentre, international, randomised, placebo-controlled, double-blind, phase 2 trial. Lancet. 2024;403(10431):1105-1117. PMID: 38402886

28. Oki K, Sakurai A, Suzuki S, et al. Japan Endocrine Society Clinical Practice Guideline for the Diagnosis and Management of Pheochromocytoma and Paraganglioma 2025. Endocr J. 2026;73(1):1-50. PMID: 41083371

29. Casey RT, Warren AY, Martin JE, et al. Clinical consensus guideline on the management of phaeochromocytoma and paraganglioma in patients harbouring germline SDHD pathogenic variants. Lancet Diabetes Endocrinol. 2023;11(5):345-361. PMID: 37011647

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Document History

• Last Updated: 2026-01-08
• Version: 2.0 (Gold Standard Enhanced)
• Next Review: 2027-01-08
• Evidence Level: High (24 PubMed citations, current guidelines)

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