Acromegaly

Question 1

What is acromegaly?

Answer 1

Clinical manifestation of excessive growth hormone

Question 2

Physiology of acromegaly?

Answer 2

• GH produce by anterior pituitary gland
• Optic chiasm sits above pituitary gland: where optic nerve crosses over to different sites of head

-Pituitary tumour that is big enough will start to press on optic chiasm leading to bitemporal hemianopia defect

Question 3

What is bitemporal hemianopia?

Answer 3

Loss of vision on outer half of both eyes

Question 4

Cause of acromegaly?

Answer 4

• Unregulated GH secretion by pituitary adenoma
• Can rarely be secondary to cancer such as lung or pancreatic cancer that secretes ectopic GH releasing hormone (GHRH) or GH

Question 5

Presentation of acromegaly if space occupying lesion?

Answer 5

Space occupying lesion:

• Headaches
• Visual field defect Bitemp hemianopia

Question 6

Presnetation of acromegaly if overgrowth of tissue?

Answer 6

• Prominent forehead and brow
• Large nose
• Large tongue
• Large hands and feet
• Large protruding jaw
• Arthritis form imbalanced growth of joints

Question 7

What other presnetations can acromegaly cause?

Answer 7

GH can cause

• Hypertrophic heart
• HT
• Colorectal cancer
• T2DM

Question 8

Treatment of Acromegaly if caused by pituitary tumour?

Answer 8

Trans-sphenoidal surgical removal

Question 9

Meds to block GH?

Answer 9

• Pegvisomant
• Somatostatin analogues
• Dopamine agonists
• Somatostatin (GH inhibitor)

Question 10

What is pegvisomant?

Answer 10

GH antagonist daily by SC injection

Question 11

What are somatostatin analogues mechanism of action?

Answer 11

Block GH release

Question 12

Example of somatostatin analogues?

Answer 12

Ocreotide

Question 13

Example of dopamine agonists?

Answer 13

Bromocriptine

Question 14

Mechanism of dopamine agonists?

Answer 14

Blocks GH release