Acromegaly

Question 1

What is the most common cause of acromegaly?

Answer 1

Pituitary somatotroph adenoma

Somatotroph adenomas (SA) occur in the anterior pituitary, arising from growth hormone-producing cells, often in the lateral wings of the gland. They account for 10-15% of pituitary adenomas

Question 2

When would acromegaly be screened for?

Answer 2

If a patient has;

• A pituitary adenoma
• Profuse sweating
• Acral growth
• Coarsening of facial features
• Carpal tunnel syndrome
• Glucose intolerance

Question 3

What % of the population have pituitary adenomas?

Answer 3

15-20%

Found on autopsy

Question 4

What % of pituitary tumours are growth hormone-secreting?

Answer 4

20%

Question 5

What is the best way to describe the onset of acromegaly?

Answer 5

Insidious - means there is often diagnostic delay

Question 6

Is acromegaly more common in men or women?

Answer 6

Neither - M=F

Question 7

Discuss the pathophysioogy of acromegaly

Answer 7

95% of cases - a pituitary somatotroph secretes excessive GH which stimulates insulin-like growth factor 1 production

This leads to the majority of the clinical manifestations of the disease

Question 8

Describe some symptoms of acromegaly

Answer 8

Facial features: enlarged nose, thick lips, prominent jaw and brow

Skin: thick, oily and skin tags

Teeth: separation of lower teeth

Speech: deep, enlarged tongue

Excessive sweating

Enlarged hands and feet

Carpal tunnel

Cardiomegaly

Arthralgia

Tiredness, hypertension, apnoea

Question 9

Discuss the consequences of a pituitary tumour

Answer 9

• Headaches
• Eyesight changes
• Menstrual cycle changes (women)
• Loss or lack of sex drive
• Erectile dysfunction (men)

Question 10

Discuss the diagnosis of acromegaly

Answer 10

• Often delayed for up to 10 years after the appearance of early signs
• Diagnosis depends on biochemical confirmation of either GH or IGF-1 hypersecretion

Question 11

Discuss the link between prolactin secretion and acromegaly

Question 12

What are the risk factors for acromegaly?

Answer 12

GPR101 overexpression

Multiple endocrine neoplasia type 1 syndrome

Isolated familial acromegaly

McCune-Albright syndrome

Carney complex

Question 13

What is the 1st line treatment of acromegaly?

Answer 13

Transsphenoidal surgery

Via the sphenoid sinus (via the nose)

60-90% remission in microadenomas (<1cm)

50% remission in macroadenomas (=>1cm)

Question 14

What is the second line treatment for acromegaly?

Answer 14

Somatostatin analogues e.g. octreotide or lanreotide or pasireotide

Question 15

What is octreotide?

Answer 15

Octreotide exerts pharmacologic actions similar to the natural hormone, somatostatin. It is an even more potent inhibitor of growth hormone, glucagon, and insulin than somatostatin

Question 16

What is acromegaly?

Answer 16

Rare chronic disease caused by excessive growth hormone secretion

Usually due to pituitary somtotrophy adenoma

Associated with increased morbidity and mortality if not preoperly treated

Question 17

What would cause a clinician to screen for acromegaly?

Answer 17

Pituitary adenoma, profuse sweating, acral growth, coarsening of facial features, carpal tunnel, arthralgia and glucose intolerance

Question 18

Discuss the epidemiology of acromegaly

Answer 18

2.8-13.7 cases per 100,000

Often recognised in middle-aged men and women

M:F 1:1

Question 19

What is the aetiology of acromegaly?

Answer 19

95% of cases due to pituitary somatotroph adenomas

• Chronically secrete excessive growth hormone swhich stimulates insulin-like growth factor 1 production leading to the majority of the clinical manfestations of the disease

Question 20

What is GPR101 overexpression?

Answer 20

G-protein coupled receptor 1

Has a role in the pituitary gland, both in the growth of cells in the gland and in the release of hormones from the gland