pituitary Flashcards
where does the anterior pituitary arise from
Rathke’s pouch
where does the posterior pituitary arise from
neural tissue
what does anterior pit secrete
ATH // TSH // GH // prolactin // FSH // LH // MSH
what does posterior pit secrete
ADH + oxytonin
size of a pituitary microadenoma vs macroadenoma
micro <1cm // macro >1cm
symptoms pituitary adenomas
hormone excess (cushings, acromegaly, galactorrhoe) // hypopituitarism // headaches // bitemperoal hemianopia
what type of tumours cause hypopituitarism
non-functioning (non-hormonal)
how do pituitary adenomas cause visual problems
compress optic chiasm –> bitemporal heminopia
invx pituitary adenomas
blood profile // visual field // MRI
mx non-function pit adenomas
transphenoidal transnasal hypophysectomy if growing
most common pit adenoma
prolcatinoma
function prolactin
stimulates breast + milk // decreased GnRH –> decreased LH
what increases secretion of prolactin
thyrotroptin (TRH from hypo) // pregnancy, breastfeeding // oestrogen // sleep // stress //
what drugs increase production of prolactin
dopamine antagonists eg metoclopramide, haloperidol, phenothiazine
what inhibits prolactin secretion
dopamine
what conditions raised prolactin
prolactinoma // hypothyroid (increased TRH) // PCOS // acromegaly
symptoms prolactinoma in women
amenorrhoea // infertile // galactorrhea // osteoporosis
symptoms prolactinoma men
impotence // loss of libido // galactorrhea
symptoms prolactinoma men + women
headache, vision, hypopituitarism
diagnosis prolactinoma
MRI + serum prolactin
1st line mx prolactinoma
dopamine agonist eg cabergoline, bromocriptine
SE dopamine agonists
N+V // post hypotension // hallucinations // fibrosis (bromocriptine)
2nd line mx prolactinoma
surgery - if cannot tolerate meds
what hormone is secreted in acromegaly
growth hormone
symptoms acromegaly
sharp face, big hands and feet // big tongue, bulging tongue // excessive sweating // headache, bitempotral hemianopia // galactorrhea
what can acromegaly be assoc with
MEN 1
complciations acromgealy
HTN // diabetes // cardiomyopathy // colorectal cancer
first line invx acromegaly
serum IGF1
invx to confirm acromegaly
oral glucose tolerance test // in normal patient hyperglycaemia suppresses GH <2 /// in acromegaly hyperglycaemia does not suppress GH
what blood test can monitor acromegaly
serum IGF1
imaging acromegaly
MRI
1st line mx acromgealy
trans-sphenoidal surgery
medication mx acromgealy (3)
somatostatin analogue eg ocreatide // GH receptor antagonist eg pegvisomant // dopamine agonist eg bromocriptine
what is pituitary apoplexy
haemorrhage or infarction of pit tumour –> sudden enlargement of tumour
symptoms pituitary apoplexy
sudden onset severe headache // vomiting // neck stiffness // visual symptoms // hypopituitary symptoms eg hypotension, hyponatraemia
eye symptoms pituitary apoplexy
extraocular nerve palsy // bitemporal superior quadrant defect
invx pituitary apoplexy
MRI
mx pituitary apoplexy
urgent steroids (bc decreased ACTCH) // maybe fluids, maybe surgery
causes hypopituitarism
compression by non-functional adenoma // pit apoplexy // Sheehans // hypothalamic tumour // trauma // radiation
what is Sheehans syndrome
postpartum haemorrhage –> pituitary necrosis
features hypopituitarism from the hormones
ACTH –> tired + post hypotension // FSH + LH –> amenorrhoea, infertility, low libido // TSH –> constipated, cold, slow cognition, dry skin // GH –> short stature
invx hypopituitarism
hormone profiles // insulin stress test // MRI
insulin stress test
give IV insulin –> GH + cortisol should rise (if they do not = hypopituitarism)
contraindications insulin stress test
epilepsy, IHD, adrenal insufficiency
