Acromegaly Flashcards
Pituitary Disorder
What is the most common cause of acromegaly?
A GH-secreting pituitary adenoma
What is the difference between acromegaly and gigantism?
Gigantism occurs in children before epiphyseal fusion, resulting in increased height.
Acromegaly occurs in adults after epiphyseal fusion, causing thickened soft tissues but no increase in height
What are the main symptoms of acromegaly?
(1) Thickened skin
(2) Large jaw/hands
(3) Snoring
(4) Headaches
(5) Hypertension
(6) Diabetes
(7) Local pituitary effects
(eg, visual field defects)
(8) GIANT
(9) increased sweating
(10) Pituitary mass
What is the screening test for acromegaly?
IGF-1 (age- and sex-matched)
Elevated levels suggest acromegaly
What does a normal IGF-1 level mean in acromegaly?
If IGF-1 is normal, acromegaly is unlikely
What is the diagnostic test for acromegaly?
Oral Glucose Tolerance Test (OGTT)
In acromegaly, after drinking glucose, the growth hormone (GH) should normally decrease. But in acromegaly, GH either doesn’t decrease at all or even increases when it should go down. This is a key sign of the condition
What is the gold standard test for diagnosing acromegaly?
GTT suppression test
= 75g glucose
= Checking GH at 0, 30, 60, 90, and 120 minutes.
If GH doesn’t suppress to <0.4 µg/L or it rises, acromegaly is confirmed
What is the first-line treatment for acromegaly?
Pituitary surgery
(transsphenoidal approach)
= Effective for microadenomas with a 90% cure rate
What imaging is used in diagnosing acromegaly?
- MRI/CT pituitary scan to check pituitary adenoma size
- Visual field testing
- Pituitary function tests
What to do if surgery doesn’t normalize GH levels?
- Radiotherapy
- Somatostatin
- Dopamine agonists
(10-15% effectiveness) - GH antagonists
(eg, Pegvisomant, last-line therapy)
What are the side effects of somatostatin analogues?
Local stinging, GI upset, long-term gallstones
What cardiovascular risks are linked to acromegaly?
Hypertension, cardiac failure, and early cardiovascular death
What are the complications of GH excess in acromegaly?
Colon polyps
colon cancer
increased risk of heart failure
How do somatostatin analogues help in acromegaly?
(1) They reduce GH secretion
(2) Relieve symptoms
(3) Improve outcomes
= especially before surgery or when surgery fails
Is surgery the first-line treatment for prolactinoma?
False.
Dopamine agonists
(eg, cabergoline, bromocriptine)
are the first-line treatment
Does acromegaly increase the risk of colon cancer?
yes
What does the term Acromegaly mean?
Big Limbs
Apart from neurosurgery and medical therapy what other modalities of treatment can be used to treat pituitary tumours?
Radiotherapy
What is the common metabolic complication of Acromegaly?
Type 2 diabetes
What long term imaging / screening tests do patients with Acromegaly require?
Echocardiography and colonoscopy
What is the first line test for Acromegaly?
IGF-1
Physical Signs of acromegaly include what?
Prognathia (protruding jaw)
Macroglossia (enlarged tongue)
Enlarged hands and feet
Coarse facial features (widened nose, enlarged lips)
Thickened skin
Symptoms of acromegaly include what?
Fatigue
Headaches
Snoring or sleep apnea
Increased sweating
Joint pain
A 47-year-old gentleman presents to his GP with headaches. On examination, the GP notes a set of surprising features. These include: frontal bossing, prognathism and visibly swollen hands. Additionally, the patient reports increased sweating and tingling in the thumb and index finger of the right hand.
Given the likely diagnosis, what would be most suitable to routinely monitor disease progression?
Serum IGF-1 level
A 52-year-old male is referred to an endocrinology clinic with a recent diagnosis of acromegaly. The recent scans confirm the presence of an enclosed pituitary tumour.
What is the next best step in the management of this patient?
Transsphenoidal surgery
A 45-year-old male is referred to an endocrinologist with a confirmed parathyroid adenoma, acromegaly and recurrent peptic ulcers.
What is the most likely diagnosis?
Multiple endocrine neoplasia I (MEN I)
MEN I involves what?
(Multiple endocrine neoplasia I)
- Parathyroid hyperplasia/adenoma
- Pituitary prolactinoma or GH secreting tumours (acromegaly)
- Pancreas endocrine tumours in 70% of cases. These include insulinoma and gastrinoma, which explain peptic ulceration
Normal serum growth hormone following oral glucose suggests what
acromegaly
as should’ve decreased/ suppressed
Suppressed serum growth hormone following oral glucose suggests what
negative (normal) result in an oral glucose tolerance test
Major complications of acromegaly
- Type 2 diabetes
- Obstructive sleep apnoea
- Carpal tunnel syndrome
- Visual loss
- Ischaemic heart disease
A 33-year-old man with tingling in his thumb, index and middle finger has been referred for endocrine consultation. He also complains of waking up incredibly tired and says his wife complains that he snores. On examination, he is noted to have a prominent brow ridge. Looking at old photos, it becomes clear that his facial appearance has drastically changed over time.
After some blood tests and an MRI scan, he is prescribed octreotide. What is the mechanism of action of this drug?
Somatostatin
Excessive growth hormone means
Acromegaly
A 53-year-old male presents to his GP for an insurance medical. The GP notices that the patient has coarse facial features, a larger tongue than expected and oily skin. The patient is also sweating excessively. An excess of which hormone is likely to be responsible for this patient’s symptoms?
Growth Hormone
What visual field defect will the patient exhibit in acromegaly?
Bitemporal hemianopia
