Pituitary Disorders Flashcards
(37 cards)
What are the hormones secreted by the pituitary?
Anterior - ACTH - GH - TSH - FSH and LH - Prolactin Posterior - Oxytocin - ADH
What tests do you do if there is too much of a hormone?
You try and suppress it
-e.g. oral glucose tolerance test for GH excess
What tests do you do if there is not enough of a hormone?
Try to stimulate it
- e.g. synACTHen test for steroid deficiency
What is hypopituitarism?
Failure of anterior pituitary function
- can affect a single hormonal axis or all the hormones (panhypopituitarism)
Leads to secondary gonadal/thyroid/adrenal failure
Need multiple hormone replacement
Name some possible causes of hypopituitarism.
Tumours Radiotherapy Infarction/haemorrhage (apoplexy) - associated headache/visual disturbance - associated PPH Infiltration (e.g. sarcoid) Trauma Lymphocytic hypophysitis
Describe the deficiency replacement needed for hypopituitarism.
ACTH - hydrocortisone TSH - thyroxine (not given first as it speeds up the metabolic rate) FSH/LH - testosterone or oestrogen GH - growth hormone Prolactin - no replacement
Name some causes of high prolactin.
Prolactinomas Physiological - lactation/pregnancy Drugs (block dopamine) - tricyclics/antiemetics/carbidopa Stalk effect - due to loss of inhibitory dopamine
What important questions must you ask yourself about pituitary tumours?
How big is the tumour?
- <1cm - micro
- >2cm - macro
Is it functional?
It is inhibiting the function of the rest of the pituitary?
If it compressing any surrounding structures?
What are the three main types of pituitary tumour?
Non-functioning (majority) Functioning - prolatinoma - GH - ACTH - TSH Others - craniopharyngioma - pituitary cancer
What are the issues associated with non-functioning pituitary tumours?
Visual field defects
Headache
Stops function of other pituitary hormones
Eye movement problems
How are non-functioning pituitary tumours investigated?
Imaging
Visual field assessment
Prolactin
Other pituitary hormones
How are non-functioning pituitary tumours treated?
If aysymptomatic - it doesn’t require treatment
Symptomatic
- surgery
- radiotherapy
What are the clinical features of a prolactinoma?
Galactorrhoea Headaches Mass effect Visual field defect Amenorrhoea or erectile dysfunction
What is the most common reason for a woman presenting with amenorrhoea (outside of pregnancy)?
Prolactinoma
How are prolactinoma’s diagnosed?
Serum prolactin - over 6000 MRI pituitary Test remaining pituitary function - gonadal function and thyroid hormones affected most
How are prolactinoma’s treated?
Medical - dopamine agonist (e.g. cabergoline/bromocriptine/quinagolide) Surgery - visual field compromise - failure of medical therapy
What are the effects of acromeagly before puberty?
Don’t stop growing
Gigantism
What are the features of acromegaly?
Sweats and headache Alteration of facial features Increased hand and feet size Visual impairment Cardiomyopathy Increased inter-dental space
How is acromeagly diagnosed?
Glucose tolerance test - normally glucose suppresses GH - if it doesn't get suppressed, GH is out of control Measure IGF-1 - end product of GH product MRI
How is acromeagly treated?
Surgery (first) - tumours often can't be fully removed Drugs - somatostain analogue (inhibits GH) - dopamine agonist (prevents GH release) - GH receptor agonist Radiotherapy - residual tumour/ongoing symptoms
What is Cushing’s disease?
Pituitary tumour releasing ACTH
- a cause of Cushing’s syndrome
How is Cushing’s disease diagnosed?
Dexamethasone (steriods) suppression test
- causes ACTH to decrease in normal patients
What are the symptoms of Cushing’s syndrome?
Euphoria Moon face Red (plethoric) cheeks Increased abdominal fat Easy bruising Poor wound healing Muscle wasting in the arms and legs Thinning of the skin Hypertension Buffalo hump
How is Cushing’s disease treated?
Surgery (first line) - remove the pituitary tumour Bilateral adrenalectomy Medical therapy - ketoconazole or metyrapone Radiotherapy
