Endocrine - Acromegaly Flashcards
What is the pathophysiology of acromegaly?
Pituitary adenoma causes unregulated growth hormone secretion
Adenoma can be microscopic or large enough to compress local structures
What is a rare cause of acromegaly?
Paraneoplastic syndrome
Cancer such as lung or pancreatic can secrete ectopic GHRH or GH
What symptoms can a space-occupying pituitary tumour cause?
Headaches
Bitemporal hemianopia
What does excess growth hormone lead to?
Frontal bossing
Coarse, sweaty skin
Macroglossia
Large nose
Large hands and feet
Prognathism (large protruding jaw)
What condition is strongly associated with acromegaly?
Carpal tunnel syndrome
What investigations are used for acromegaly?
Insulin-like growth factor-1 (IGF-1)
- Testing growth hormone directly is unreliable as it has pulsatile secretion
MRI of pituitary
- Diagnose pituitary adenoma
Growth hormone suppression test
- 75g glucose drink
- Glucose should suppress the GH level, failure indicates acromegaly
How is acromegaly treated?
Trans-sphenoidal surgery
Removes pituitary adenomas
Surgical removal of tumours
Radiotherapy as part of treatment
What medical options can be used for reducing growth hormone where surgery is not indicated?
First line
Octreotide
- Somatostatin analogue
- Blocks GH release
Second line
Pegvisomant
- GH receptor antagonist (daily subcut)
Used with other therapies
Bromocriptine
- Dopamine agonist
- Blocks GH release
