acromegaly

Question 1

define acromegaly

Answer 1

Excess GH production, usually due to GH-secreting pituitary adenoma

Question 2

what is a growth hormone- ( GH/somatotropin)?

Answer 2

is a peptide hormone secreted by the anterior pituitary gland.

Question 3

what are the causes of acromegaly?

Answer 3

-Primary GH-secreting pituitary adenoma
-Ectopic GH-secreting tumours
e.g. Pancreatic-Islet Cell Tumours and Lymphoma.
-Iatrogenic GH
-Excessive GHRH (Rare)
e.g. Hypothalamic Hamartomas, Bronchial Carcinoid Tumours, Small cell lung cancer.

Question 4

what does the secretion of GH lead to and what does it stimulate?

Answer 4

-GH leads to increased Insulin Growth Factor –1 (IFG1) secreted by the liver, which stimulates protein synthesis, cell division, lipolysis etc… for growth.

Question 5

what can excessive GH cause?

Answer 5

Excess GH however causes excessive enlargement and growth of bone and soft tissue; Acromegaly

Question 6

what are the signs of acromegaly?

Answer 6

-Acral Enlargement (Clubbing/Enlargement of hands and feet)
-Big tongue and widely spaced teeth
-Deep voice
-Prominent Superior Orbital fissure
-Puffy Lips, Thick Eyelid, Big Nose

Question 7

what are the symptoms of acromegaly?

Answer 7

-Joint Pain
-Wrist Pain and Numbness (Carpal Tunnel Syndrome)
-Sleep/Snoring disorders (Sleep Apnoea)
-Headache and visual disturbance
-Erectile Dysfunction/Low libido

Question 8

describe the epidemiology of acromegaly

Answer 8

Occurs in adults after the epiphyseal plates have fused; characterised by enlarged features

Question 9

describe the epidemiology of giantism

Answer 9

Occurs in children before fusion of EP; have tall height

Question 10

what are the risk factors for acromegaly?

Answer 10

Familial condition – Multiple Endocrine Neoplasia Type 1

Question 11

what are the two types of treatment/ management of acromegaly?

Answer 11

1. surgical
2. medical

Question 12

describe the surgical treatment/ management of acromegaly

Answer 12

-Endoscopic Transsphenoidal Surgery – Removes GH-secreting pituitary adenoma
-Surgical Removal of Ectopic cause

Question 13

describe the medical treatment/ management of acromegaly

Answer 13

-Somatostatin Analogues (Octreotide, Lanreotide)
-Dopamine Agonists (Cabergoline, Bromocriptine)
-GH Antagonists (Pegvisomant)

Question 14

what is the first line test of suspected acromegaly?

Answer 14

Measure serum IGF-1 levels NOT GH (as GH varies throughout the day).

Question 15

what is the gold standard test for acromegaly?

Answer 15

ORAL GLUCOSE TOLERANCE TEST: 75g of oral glucose (Glucose suppresses GH).If after 2 hours GH conc. is >1ng/mL, Acromegaly is diagnosed.

Question 16

what additional tests need to be done to diagnose acromegaly?

Answer 16

Plasma Prolactin: Prolactin levels may be raised in Acromegaly (Stalk compression, inhibits dopamine)

Question 17

what should be done once acromegaly is diagnosed?

Answer 17

• A pituitary MRI should be completed once Acromegaly is diagnosed.

Question 18

after diagnosis, if there’s a visible mass on the pituitary MRI, what should you? ( in acromegaly)

Answer 18

-Visible mass: Proceed to treatment

Question 19

after diagnosis, if there’s not a visible mass on the pituitary MRI, what should you? ( in acromegaly)

Answer 19

If not, a CT of the chest or abdomen should be done with serum GHRH measurement.

Question 20

what is the age of incidence of acromegaly?

Answer 20

; Men = 40, Women = 45