Can pheochromocytoma cause panic attacks?

Pheochromocytoma and Panic Attacks: The Connection

Yes, pheochromocytoma can cause symptoms that mimic or present as panic attacks due to the episodic release of catecholamines that trigger paroxysmal symptoms similar to anxiety disorders. 1, 2

Pathophysiological Mechanism

• Pheochromocytomas are catecholamine-producing tumors that cause episodic or sustained release of norepinephrine and epinephrine 1
• These catecholamines act on alpha and beta-adrenergic receptors throughout the body, causing symptoms that can closely resemble panic attacks 2
• The increased blood pressure variability characteristic of pheochromocytoma constitutes an independent risk factor for cardiovascular morbidity and mortality beyond the increased blood pressure itself 1

Clinical Presentation

• Approximately 95% of patients with pheochromocytoma present with hypertension, with 50% having sustained hypertension and 50% having paroxysmal (episodic) hypertension 2
• The classic triad of symptoms includes:
  • Headaches
  • Palpitations
  • Sweating
• This triad, when occurring in an episodic fashion, has a diagnostic specificity of 90% 1
• Additional symptoms that overlap with panic attacks include:
  • Anxiety
  • Tremor
  • Pallor
  • Diaphoresis ("cold sweat")
  • Tachycardia 1, 3

Differentiating from True Panic Disorder

• Despite the similarity in symptoms, research shows that the elevated catecholamines from pheochromocytomas are not always sufficient to elicit a true anxiety disorder 4
• In a study of 17 patients with active pheochromocytoma, only one received a diagnosis of possible panic disorder, and none described the severe apprehension or fear characteristic of panic attacks 4
• The term "pseudopheochromocytoma" has been used to describe paroxysmal hypertension without significantly elevated catecholamine concentrations, which can occur in patients with anxiety disorders 5

Diagnostic Considerations

• Pheochromocytoma should be considered in any patient with:
  • Paroxysmal hypertension
  • Resistant hypertension
  • Hypertension with the classic triad of symptoms
  • Apparent panic attacks with concurrent hypertension 1
• The best screening test for pheochromocytoma is plasma free metanephrines (normetanephrine and metanephrine), which carries a 99% sensitivity and an 89% specificity 1, 2
• If plasma testing is equivocal (less than fourfold elevation), a 24-hour urine collection for catecholamines and metanephrines should be performed 1, 2

Clinical Pitfalls

• Despite improved diagnostic techniques, there remains an average of 3 years between initial symptoms and final diagnosis of pheochromocytoma 1, 2
• Many cases are missed altogether, with autopsy studies showing that pheochromocytomas contributed to 55% of deaths and were not suspected in 75% of cases 1, 2
• Pheochromocytoma can be mistaken for:
  • Panic disorder
  • Generalized anxiety disorder
  • Essential hypertension
  • Migraine headaches
  • Cardiac arrhythmias 3, 6

Management Implications

• Once diagnosed, pheochromocytoma requires proper preoperative medical management:
  • Alpha-adrenergic blockade must be initiated at least 7-14 days before surgery 7
  • Beta-blockers should ONLY be added after adequate alpha blockade to control tachyarrhythmias 7
  • Monotherapy with beta-blockers can elicit hypertension and is contraindicated 1
• Surgical resection is the definitive treatment for pheochromocytoma 7

Conclusion

When evaluating patients with apparent panic attacks, especially those with concurrent hypertension or other atypical features, clinicians should consider pheochromocytoma in the differential diagnosis. The overlap in symptoms between pheochromocytoma and panic disorder makes this distinction clinically important, as missing the diagnosis of pheochromocytoma can lead to significant morbidity and mortality.