Pituitary Tumours - Non functional adenomas Flashcards
microadenoma vs macroadenoma?
micro = <1cm macro = >1cm
what are some possible complications of a non-functional pituitary adenoma which causes the pituitary to be too big?
compression of optic chiasm
compression of certain cranial nerves (3,4,6)
what are some complications of non-functional pituitary adenoma which causes the pituitary to be too small?
hypoadrenalism hypothyroidism hypogonadism diabetes insipidus GH deficiency
what sight problem is caused by pituitary tumour compressing on optic chiasm?
bitemporal hemianopia
what physiological things can cause increased prolactin?
breast feeding
pregnancy
stress
sleep
wht drugs can cause raised prolactin?
dopamine antagonists (metoclopramide)
antipsychotics (phenothiazides)
antidepressants, oestopgens, coccaine
name 3 pathological causes of raised prolactin?
hypothyroidism
stalk lesions (iatrogenic, car accident, tumour pressing on tumour etc)
prolactinoma
what are some clinical signs and symptoms in females of raised prolactin?
early presentation galactorrhoea menstrual irregularity amenorrhoea infertility
what are the male symptoms and signs of raised prolactin?
late presentation impotence visual field abnormal headache anterior pituitary malfunction
investigations for prolactinoma?
serum prolactin concentration
MRI of pituitary
visual field (possible bitemporal hemianiopia)
pituitary function tests
what features can be seen on MRI in prolactinoma?
macroprolactinoma or macroprolactinoma
what are the medical treatments for prolactinoma?
dopamine antagonists
- mainly cabergoline (dostinex)
- quinagolide (norprolac)
- bromocriptine
what are the side effects of dopamine agonists?
nausea/vomiting
low mood
fibrosis (heart valves/retroperitoneal)
what are the features of acromegaly?
giant (if onset before epiphyseal fusion)
thickened soft tissues (skin, large jaw, sweaty, large hands)
snoring/sleep apnoea (thickened nasopharynx)
hypertension, cardiac failure
headaches
diabetes mellitus
local pituitary effects (visual fields, hypopituitarism)
early CV death
colonic polyps and colon cancer
what causes acromegaly?
GH excess
how is acromegaly diagnosed?
check IGF1 levels
GTT suppression test
- normal = GH suppresses to <0.4 after glucose
- acromegaly = GH unchanged/ not suppressed, paradoxical rise or remains >1 after glucose
can use CT or MRI
can do pituitary function tests to exclude other hormone deficiencies as the cause of symptoms
how is acromegaly treated?
pituitary surgery external radiotherapy to pituitary fossa retest GTT (needs retreatment if GH >1) - drugs - radiotherapy - repeat surgery if curable
what is the most successful treatment for acromegaly?
surgery
- works best for microadenoma rather than macro
name 3 drugs used for acromegaly?
somatostatin analogues (octreotide) dopamine agnonists GH antagonists
what do somatostatin analogies do?
reduced GH in most people
can cause 30-50% decrease in tumour size (over 6-12 months)
can be used pre-op to relieve headache and improve outcome
what are the side effects of somatostatin analogues?
local stinging short term - flatulence - diarrhoea - abdominal pains long term - gallstones
name 3 somatostatin analogues used in acromegaly?
sandostatin LAR
lanreotide autogel
pasireotide LAR
how are dopamine agonists delivered and how effective are they in acromegaly?
cabergoline up to 3g weekly
works in 10-15%
better in co-secreting prolactin
how are GH antagonists delivered and what does it do?
SC injection 10-30 mg daily
binds to GH receptor and blocks GH activity
doesn’t cause decrease in tumour size
IGF-1 decreases but serum GH may increase
last line therapy
what is included in acromegaly follow up?
check GH - <0.4 post GTT - <2 random check pituitary hormones (esp thyroid) cancer surveillance cardio risk factors sleep apnoea
