Phaeochromocytoma

Introduction

• Phaeochromocytomas = Catecholamine-secreting tumors arising from chromaffin cells of adrenal medulla
• Catecholamine-secreting paragangliomas = Catecholamine-secreting tumors from sympathetic ganglia
• <0.2% of HTN patients
• 40% have disease as part of familial disorder (more likely to be bilateral in this case)
  • Present at younger ages
  • Includes von Hippel-Lindau, MEN2 and NF1

Clinical presentations

• Symptoms present in 50% of cases and typically paroxysmal
• Classic triad: Episodic headache, sweating, tachycardia (if all 3 = >90% sensitive)
• 50% have paroxysmal HTN
• Most do not have all three
• 5-15% of patients have normal BP
• 90% of symptomatic patients suffer headache
• Unexplained orthostatic hypotension on b/g of hypertension often seen
• Panic-attack type symptoms can occur
• Rarely can present as phaeochromocytoma crisis with hyper/hypotension, hyperthermia, ALOC and organ dysfunction
• Cardiomyopathy is a rare presentation (similar to Takotsubo)
• Paroxysmal elevations in BP in the setting of diagnostic procedures, induction of anaesthesia, surgery, tyramine intake, beta-blockers, TCA’s, steroids or MAOi should have diagnostic testing performed

Asymptomatic patients

• Incidentalomas are common

Tumor characteristics

• 95% are intra-abdominal
• 90% intra-adrenal
• 10% extra-adrenal paraganglionomas
• 10% are malignant

Investigation

• If low clinical suspicion: 24 hour urinary fractionated catecholamines and metanephrines
• High clinical suspicion: Plasma fractionated metanephrines

Treatment

• Medical preparation for surgery
  • Avoid beta-blockers (in absence of alpha blockade), glucagon, histamine and metoclopramide
  • Control hypertension and volume expand
    • Alpha blockade first
      • Phenoxybenzamine preferred for 10-14 days
      • Prazosin a reasonable alternative
    • High sodium diet after 2-3 days of alpha blockade
    • Beta-blockade second
      • Initiate beta-blocker after 1 week of alpha blockade if HTN controlled
      • Propranolol 10mg PO q6h
• Adrenalectomy then performed

Management of hypertensive crisis

• Sodium nitroprusside 0.5-5mcg/kg/min infusion

Last Updated on October 6, 2021 by Andrew Crofton