Acromegaly Flashcards
What is the most common cause of acromegaly?
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
When would acromegaly be screened for?
If a patient has;
- A pituitary adenoma
- Profuse sweating
- Acral growth
- Coarsening of facial features
- Carpal tunnel syndrome
- Glucose intolerance
What % of the population have pituitary adenomas?
15-20%
Found on autopsy
What % of pituitary tumours are growth hormone-secreting?
20%
What is the best way to describe the onset of acromegaly?
Insidious - means there is often diagnostic delay
Is acromegaly more common in men or women?
Neither - M=F
Discuss the pathophysioogy of acromegaly
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
Describe some symptoms of acromegaly
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
Discuss the consequences of a pituitary tumour
- Headaches
- Eyesight changes
- Menstrual cycle changes (women)
- Loss or lack of sex drive
- Erectile dysfunction (men)
Discuss the diagnosis of acromegaly
- 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
Discuss the link between prolactin secretion and acromegaly
What are the risk factors for acromegaly?
GPR101 overexpression
Multiple endocrine neoplasia type 1 syndrome
Isolated familial acromegaly
McCune-Albright syndrome
Carney complex
What is the 1st line treatment of acromegaly?
Transsphenoidal surgery
Via the sphenoid sinus (via the nose)
60-90% remission in microadenomas (<1cm)
50% remission in macroadenomas (=>1cm)
What is the second line treatment for acromegaly?
Somatostatin analogues e.g. octreotide or lanreotide or pasireotide
What is octreotide?
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
What is acromegaly?
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
What would cause a clinician to screen for acromegaly?
Pituitary adenoma, profuse sweating, acral growth, coarsening of facial features, carpal tunnel, arthralgia and glucose intolerance
Discuss the epidemiology of acromegaly
2.8-13.7 cases per 100,000
Often recognised in middle-aged men and women
M:F 1:1
What is the aetiology of acromegaly?
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
What is GPR101 overexpression?
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
