Acromegaly Flashcards
Define acromegaly
Clinical manifestation of excessive growth hormone (GH)
What produces growth hormone
Produced by the anterior pituitary gladn
What is the other name of growth hormone
Somatotropin
Fill in the blank of the growth hormone axis
What is the most common cause of acromegaly (accounting for 95% of cases)
Hormone secreting pituitary adenoma
The most common cause of acromegaly is pituitary adenoma. Name some of the other causes of acromegaly
Ectopic GHRH or GH production by tumours e.g. pancreatic, neuroendocrine tumours
Name some of the clinical features of acromegaly
- Enlargement of hands and feet
- Frontal bossing (prominent forehead)
- Macrognathia (large jaw)
- May also be related to the aetiology - e.g. mass effect of a pituitary adenoma resulting in visual field defects and headache
- Associated systemic conditions e.g. cardiovascular disease, diabetes, obstructive sleep apnoea
How is acromegaly diagnosed
Biochemical testing: IGF-1 levels and oral glucose tolerance test
Imaging: Pituitary MRI (to visualise pituitary adenoma (most common cause))
Name the two biochemical tests used to diagnosis acromegaly
IGF-1 levels
Oral glucose tolerance test
What are the expected IGF-1 levels in patients with acromegaly
Vast majority of patients with acromegaly will have raised serum IGF-1
What are the expected results of the oral glucose tolerance test in patients with acromegaly
Highly specific diagnostic test.
Serum GH measured before and after glucose stimulation.
Normal – GH suppressed after
In acromegaly – GH unsuppressed
What is the first line therapy for acromegaly
Trans-sphenoidal surgery i.e. removal of the pituitary adenoma via the nose
Name a complication of acromegaly
Increased risk of colonic polyps (which can lead to colonic adenocarcinoma)
