Acromegaly

Question 1

Define acromegaly

Answer 1

Constellation of signs and symptoms caused by
hypersecretion of GH in adults

Excess GH before puberty results in GIGANTISM

Question 2

Explain the aetiology/risk factors of acromegaly

Answer 2

Most cases are caused by a GH-secreting pituitary adenoma

RARELY caused by excess GHRH causing somatotroph hyperplasia from hypothalamic ganglioneuroma, bronchial carcinoid or pancreatic tumours

Question 3

Summarise the epidemiology of acromegaly

Answer 3

RARE
5/1,000,000
Age affected: 40-50 yrs

Question 4

Recognise the presenting symptoms of acromegaly

Answer 4

VERY INSIDIOUS

Rings and shoes becoming tight
Increased sweating
Headaches
Carpal tunnel syndrome

Hypopituitary symptoms:
Hypogonadism
Hypothyroidism
Hypoadrenalism

Visual disturbances (due to compression of optic chiasm by tumour)

Hyperprolactinaemia leading to:
Irregular periods
Decreased libido
Impotence

Question 5

Recognise the signs of acromegaly on physical examination

Answer 5

Large spade-like hands
Thick greasy skin
Carpel tunnel syndrome signs
Premature osteoarthritis

Prominent eyebrow ridge
Prominent cheeks
Broad nose bridge
Prominent nasolabial folds
Thick lips
Increased gap between teeth
Large tongue
Prognathism
Husky resonant voice (due to thickening of vocal cords)

Visual Field Loss - Bitemporal superior quadrantopia progressing to bitemporal hemianopia

Multinodular goitre

Feet Enlarged

Question 6

Identify appropriate investigations for acromegaly

Answer 6

Serum IGF-1 - useful screening test (GH stimulates it)

Oral Glucose Tolerance Test (OGTT) - Positive result: failure of suppression of GH after 75 g oral glucose load

Pituitary Function Tests
9am cortisol
Free T4 and TSH
LH and FSH
Testosterone
Prolactin

MRI of Brain - visualise the pituitary adenoma

Question 7

Generate a management plan for acromegaly

Answer 7

Surgical-trans-sphenoidal hypophysectomy

Radiotherapy - adjunctive to surgery

Medical - if surgery is contraindicated or refused
Subcutaneous Somatostatin Analogues
Examples: octreotide, lanreotide

Side-effects: abdominal pain, steatorrhoea, glucose intolerance, gallstones

Oral Dopamine Agonists
Examples: bromocriptine, cabergoline
•
Side-effects: nausea, vomiting, constipation, postural hypotension, psychosis (RARE)

GH Antagonist (pegvisomant)

Monitor - GH and IGF1 levels can be used to monitor disease control

Question 8

Identify possible complications of acromegaly

Answer 8

Cardiomegaly
Hypertension

Obstructive sleep apnoea

Colonic polyps

Hyperprolactinaemia (in 30% of cases)

Hypercalcaemia
Hyperphosphataemia
Renal stones
Diabetes mellitus
Hypertriglyceridaemia

Depression
Psychosis (from dopamine agonists)

Complications of Surgery
Nasoseptal perforation
Hypopituitarism
Adenoma recurrence
CSF leak
Infection

Question 9

Summarise the prognosis for patients with acromegaly

Answer 9

GOOD with early diagnosis and treatment

Physical changes are irreversible