Catecholamine-secreting tumour that typically derived from chromaffin cells of the adrenal medulla

Aetiology

• 10% (up to 30%) are extra-adrenal → paragangliomas
  • Occur elsewhere in the sympathetic chain - typically occur in the head and neck but are also found in the thorax, pelvis and bladder
  • More closely associated with genetic associations than phaeochromocytoma
• 10% are bilateral (up to 50% in familial cases)
• 10% are biologically malignant (metastasis)
  • More common (20-40%) in paragangliomas
• 10% are NOT associated with hypertension
• 25% are familial
  • Germline mutations in one of several known pre-disposing genes including neurofibroma type 1, RET (MEN2), VHL, succinate dehydrogenase enzymes and tuberous sclerosis
  • Younger presentation, more often bilateral
  • More often malignant if associated with germline mutation of B unit of succinade dehydroxinate

Pathophysiology

• Secrete catecholamines
• Rare cause of secondary hypertension

Spread

• Propensity for skeletal metastasis
• Other sites include regional lymph nodes, liver and lung

Clinical features

• Insidious onset in most patients
• 10% have no symptoms of adrenal disease

Symptoms

• Classical triad (up to 90% of cases) - hypertension, headache, sweating
• Paroxysmal sweating, headache, anxiety
  • Episodes triggered by stress, exercise, posture, palpation of the tumour
• Paraganglioma of the bladder associated with micturition during episodes