Acromegaly

Question 1

What is Acromegaly?

Answer 1

• Excessive secretion of GH

Question 2

What can cause excessive GH secretion?

Answer 2

• Pituitary adenoma - most common
• Ectopic from lung/pancreatic/ovarian cancer
  
  • Growth hormone releasing hormone

Question 3

What is the presentation of acromegaly like?

Answer 3

• Space occupying lesion
  
  • Headaches
  • Bitemporal hemianopia
• Overgrowth of tissues
  
  • frontal bossing
  • large nose
  • macroglossia
  • large hands and feet
  • prognatism
  • arthirtis
• Organ
  • Hypertrophic heart
  • Hypertension
  • Type 2 diabetes
  • Colorectal cancer

Question 4

What Ix would you order for Acromegaly?

Answer 4

• Bloods
  
  • glucose, phosphate, calcium, triglycerides - all raise
• IGF-1
• Oral glucose tolerance test
• MRI of brain
• Visual test field
• CT scan - if ectopic GH suspected

Question 5

Why is random GH test unreliable?

Answer 5

• secretion is pulsatile
• peaks of acromegaly and normal levels overlap

Question 6

How does oral glucose tolerance test work?

Answer 6

1. glucose inhibits GH release
2. If glucose fails to suppress GH < 1.0mcg/L, this confirms diagnosis of acromegaly

Question 7

What are the differential diagnosis of Acromegaly?

Answer 7

• pseudo-acromegaly
  
  • same physical appearance, no elevated Gh or IGF-1

Question 8

What is the Mx of Acromegaly?

Answer 8

• Transphenoidal surgery
• Surgical recestion of ectopic tumours
• medications
  
  • Somatostatin analogues - first choice
    
    • octreotride
    • lanreotide
  • Dopamine agonist
    
    • Bromocriptine
    • Cabergoline
  • Genetically modified GH
    
    • Pegvisomant (PEG)