Endocrinology - Acromegaly Flashcards
What is acromegaly? Causes?
Clinical manifestation of excessive growth hormone
Most commonly caused by pituitary adenoma
Rarely, can also be secondary to cancer releasing ectopic growth hormone releasing hormone (GHRH) or growth hormone. (e.g. lung or pancreatic cancer)
Presentation of acromegaly
Pituitary SOL symptoms:
- Headache
- Bitemporal hemianopia
Overgrowth of tissues:
- Prominent forehead and brow (“frontal bossing”)
- Large nose
- Large tongue (“macroglossia”)
- Large hands and feet
- Large protruding jaw (”prognathism”)
- Arthritis from imbalanced growth of joints
- Development of new skin tags
Organ dysfunction:
- Hypertrophic heart
- Hypertension
- T2DM
- Colorectal cancer
Investigations in suspected acromegaly
Insulin-like Growth Factor 1 (IGF-1) is the initial screening test (raised)
Oral glucose tolerance test whilst measuring growth hormone (high glucose normally suppresses growth hormone)
MRI brain for the pituitary tumour
Refer to ophthalmology for formal visual field testing
Can also measure BP and glucose/HbA1c to test for hypertension/T2DM
Treatment of acromegaly
Trans-sphenoidal removal of pituitary is definitive treatment, or surgical removal of pancreatic/lung cancer causing ectopic secretion
Interim medications to block GH e.g.:
- Pegvisomant (GH antagonist given subcutaneously and daily)
- Somatostatin analogues to block GH release (e.g. ocreotide)
- Dopamine agonists to block GH release (e.g. bromocriptine)
