Growth hormone (GH) stimulates skeletal and soft tissue growth - GH excess therefore produces gigantism in children (if acquired before epiphyseal fusion) and acromegaly in adults

Aetiology

• Nearly always due to a GH-secreting pituitary adenoma

Clinical features

• Giant (before epiphyseal fusion)
• Thickened soft tissues - skin, large jaw, sweaty, large hands
• Snoring/sleep apnoea (thickened nasopharynx)
• Hypertension, cardiac failure → early CV death
• Headaches (vascular)
• Diabetes mellitus
• Local pituitary effects - visual fields, hypopituitarism

Investigations

• IGF1: age and sex matched, nearly always raised
• TT suppression test: gold standard
  • 75g oral glucose: check GH at 0, 30, 60, 90, 120 min
  • Normally GH suppresses to <0.4 ug/l after glucose
  • Acromegaly indicated if GH unchanged/no suppression or paradoxical rise
• Others:
  • Visual field - bitemporal hemianopia
  • CT/MRI pituitary scan to check size of adenoma
  • Pituitary function tests for other hormones

Management

Pituitary surgery

• Transsphenoidal approach first-line
• 90% cure if microadenoma
• 50% cure if macroadenoma