Acromegaly

Question 1

what happens in acromegaly?

Answer 1

• extensive growth hormone is produced by the anterior pituitary

Question 2

what happens if a tumour is pressing on the pituitary?

Answer 2

bitemporal hemianopia affecting the superior quadrants

can also get panhypopituitarism

Question 3

what type or organ dysfunction can acromegaly cause?

Answer 3

• large heart
• hypertension
• type 2 diabetes
• colorectal cancer

Question 4

what are the medical treatments for acromegaly?

Answer 4

medical treatment is given if the tumour cannot be removed

• pegvisomant- GH antagonist which is given sub cut
• somatostatin anologues- somatostatin is also called growth hormone inhibiting hormone and. examples of somatostatin analogues included… ocreotide
• dopamine agonists such as bromocriptine are also used

Question 5

what is the most common cause of acromegaly?

Answer 5

• pituitary somatotroph adenoma

- somatotrophs are growth hormone producing cells

Question 6

why does increase in GH not cause height increase in adults?

Answer 6

epiphyseal growth plates have already fused in adults

Question 7

where can ectopic GH tumours arise?

Answer 7

• lung or pancreatic cancer

Question 8

which syndromes is acromegaly associated with?

Answer 8

MEN-1: pituitary adenomas, primary hyperparathyroidism, and pancreatic neuroendocrine tumours; MEN-1 is present in 6% of cases

McCune-Albright syndrome People with McCune-Albright syndrome develop areas of abnormal scar-like (fibrous) tissue in their bones, a condition called polyostotic fibrous dysplasia.

Question 9

why may someone with acromegaly have galactorrhea?

Answer 9

• usually happens in women

- because prolactin is increased in 20% of acromegaly cases

Question 10

what are clinical features of acromegaly?

Answer 10

• visual disturbance
• HTN
• headaches
• rings and shoes start to become tight
• polyuria and polydipsia due to T2DM
• tingling hands due to carpal tunnel syndrome
• galactorrhoea in women
• mentural irregulaity in women and erectile dysfunction in men
• coarse facial features
• spade hands
• hypertension

Question 11

what is it called when there is an GH producing pituitary tumour before the growth plates have fused?

Answer 11

gigantism-> because it affects height

Question 12

what’re the primary investigations for acromegaly?

Answer 12

• GH is not used for diagnosis as levels vary throughput the day
• so measure insulin like growth factor, which will be raised
• if IGF1 is raised or ambiguous do an oral glucose tolerance test. if it fails to suppress GH then indicates acromegaly
• following this biochemical confirmation a pituitary MRI should be done

Question 13

what are complications of acromegaly?

Answer 13

Neurological: carpal tunnel syndrome, proximal myopathy

Cardiac: cardiomyopathy, heart failure, hypertension

Respiratory: obstructive sleep apnoea

Endocrine: type 2 diabetes, panhypopituitarism

Gastrointestinal: colorectal cancer

Question 14

apart from the primary investigations, whichh other investigations should you consider for acromegaly?

Answer 14

Visual perimetry: formal assessment of visual fields. This has important implications for driving

Pituitary hormone screen: prolactin, LH, FSH, ACTH, TSH to monitor for panhypopituitarism; prolactin is raised in over 20% of patients

CT chest, abdomen, and pelvis: if an ectopic source of GH is suspected

Question 15

what is the first line management for acromegaly?

Answer 15

Surgery: trans-sphenoidal resection of the pituitary

Surgery is first-line as acromegaly can have significant systemic complications, e.g. heart failure

Question 16

what is second line management for acromegaly?

Answer 16

Medical: for patients unsuitable for surgery or if there are persistent symptoms after surgery

Somatostatin analogues: used in moderate to severe disease to directly inhibit GH release (e.g. octreotide); has an efficacy of 35-60%

Dopamine agonists: used in mild disease; cabergoline is first-line (bromocriptine is an alternative) and has 30% efficacy [2]

GH antagonist: pegvisomant is also used in severe disease but, in reality, is often avoided due to cost; once-daily subcutaneous injection. Very effective and reduces IGF-1 in up to 95% of patients, but does not reduce tumour size so surgery is still required

Question 17

what is the third line management of acromegaly?

Answer 17

Radiotherapy: reserved for patients who have failed medical and surgical treatment, or in elderly patients unsuitable for surgery