Acromegaly

Question 1

Define acromegaly AND gigantism

Answer 1

Acromegaly is a condition that is caused by an excess of growth hormone that occurs in adults after fusion of epiphyseal plates

GIGANTIs

Question 2

Define the epidemiology of acromegaly

Answer 2

• More common in men

Question 3

Define and explain the causes of acromegaly

Answer 3

1. ) Pituitary adenoma

2. ) Ectopic source: (secondary) a tumour in lung/pancreas that releases excess GHRH or GH itself

Question 4

Pathology

Answer 4

1.) GHRH released from the hypothalamus will stimulate the anterior pituitary to release GH. If an ectopic source is releasing GHRH, this will bypass the axis to stimulate the anterior pituitary to continue releasing GH

Question 5

What are the signs of acromegaly?

Answer 5

• Acral enlargement: large hands/jaw/nose
• Frontal bossing: prominent supraorbital ridge
• Macroglossia
• Hypertronic heart: HF/hypertension
• Deep voice
• Puffy lips

Question 6

What are the symptoms of acromegaly?

Answer 6

1.) Result of tumour growth Bitemporal hemianopia due to compression of the optic nerve, headaches and hypopituitarism

2. ) Metabolic effects of excess GH:
   - Excessive sweating
   - Acroparaesthesia (tingling/burning sensation in hands and feet)
   - Decreased libido
   - Amenorrhoea
   - Oligomenorrhoea
   - Galactorrhoea

Question 7

Explain the investigations involved in the diagnosis of acromegaly

Answer 7

1.) Measurement of growth hormone

Question 8

Explain the investigations involved in the diagnosis of acromegaly

Answer 8

1. ) Oral glucose tolerance test: rise in glucose suppress GH. If GH levels are still high then this is acromegaly
2. ) Serum IGF-1 levels: almost always raised in acromegaly
3. ) MRI of pituitary fossa: see adenoma

Others

• visual field test defects
• ECG + echocardiogram
• serum prolactin may be raised

Question 9

Describe the treatment options for acromegaly

Answer 9

1. ) 1st line: Removal of pituitary adenoma producing the GH via trans-sphenoidal approach (complications - hypopituitary, infection, diabetes insipidus)
2. ) Removal of ectopic source
3. ) Medication:
   - somatostatin analogues: block GH production + more potent than dopamine agonists] E.g: IM octreotide/lanreotide
   - dopamine agonists: block GH production: ORAL bromocriptine or cabergoline
   - GH agonist e.g. pegvisomant