Clinical Aspects of Pituitary Disease Flashcards
What tends to cause hypersecretion in pituitary disease?
Tumours
What tends to cause hyposecretion in pituitary disease?
Tumours
What structure do pituitary tumours often compress?
Optic chiasm
Hypersecretion of GH leads to what?
Acromegaly
Hypersecretion of ACTH leads to what?
Cushing’s disease
Hypersecretion of prolactin leads to what?
Hyperprolactinaemia
What is the main issue in acromegaly?
Soft tissue overgrowth
What are the features of acromegaly?
Spade like hands Wide feet Coarse facial features Thick lips and tongue Carpal tunnel syndrome Sweating + oily skin (caused by hypertrophy of sweat glands) May notice ring size going up
What are the complications of acromegaly?
Headache Chiasmal compression DM HTN Cardiomegaly Sleep apnoea Accelerated OA Colonic polyps and cancer
What are >95% of cases of acromegaly caused by?
Pituitary adenoma secreting xs GH
What does chiasmal compression cause?
Bitemporal hemianopia
Are GH levels diagnostic of acromegaly?
No - as they naturally fluctuate during the day
How do you diagnose acromegaly?
Measure IGF-1
If elevated/equivocal do OGTT to confirm diagnosis
How does the OGTT work to diagnose acromegaly?
Normally GH is supressed to <2mu/l with hyperglycaemia, but in acromegaly there is no suppression of GH
Apart from IGF-1, and OGTT what other investigation may be useful in acromegaly?
MRI to demonstrate pituitary adenoma
What is the first line treatment for acromegaly?
Transphenoidal surgery
What medications can be used to manage acromegaly?
Somatostatin analogues
Dopamine agonists
Pegvisomant
How do somatostatin analogues work?
Directly inhibits release of GH
Give an example of a somatostatin analogue
Octreotide
Give an example of a dopamine agonist
Bromocriptine
How does pegvisomant work?
GH receptor antagonist - prevents dimerization of GH receptor
What may be a last resort treatment in those who fail to respond to medical/surgical Mx/ or are older?
External irradiation
Cortisol is an anabolic/catabolic hormone.
Catabolic
What is cushing’s syndrome?
XS corticosteroids
What are the features of cushing’s syndrome?
Tissue breakdown - muscle, skin, bone weakness
Sodium retention - HTN, HF
Insulin antagonism - DM
What are the high value cushing’s syndromes signs and symptoms?
Skin atrophy Spontaneous purpura Proximal myopathy Osteoporosis Growth arrest in children
What are the intermediate value Cushing’s syndrome signs and symptoms?
Pink striae
Facial mooning and hirsutism
Oedema
Central obesity HTN
What is Cushing’s disease?
When the symptoms are the result of a pituitary tumour
What are the two types of Cushing’s syndrome?
ACTH dependent
ACTH independent
