Pituitary Tumours Flashcards
what are the sizes of pituitary tumours
> 1cm macroadenoma
=/<1cm microadenoma
what happens when a non functioning pituitary adenoma gets ‘too big’
compression on optic chiasma (if grows upwards)
compression on other structures (cranial nerve- 6th most likely to be affected) (lateral growth)
what happens when a non functioning pituitary adenoma gets ‘too little’
hypoadrenalism
hypothyroidism
hypogonadism (lack of periods, erectile dysfunction)
diabetes insipidus (posterior pituitary- ADH)
GH deficiency
what happens if the 6th cranial nerve is compressed
nerve allows you to look laterally- if compressed eye will squint inwards
what is bitemporal hemanopia
loss of temporal fields of vision
what is monomous hemianopia
vision defect all on one side (unlike bitemporal as on both sides)
what might cause prolactin too rise excessively
lack of dopamine from the hypthalamus
what are the physiological causes of raised prolactin
breast feeding
pregnancy
stress
sleep
what drugs can increase prolactin
dopamine antagonists (metoclopramide) antipsychotics, antidepressants, estrogens, cocaine
what should raised prolactin and loss of periods make you think of
pregnancy
what are the pathological causes of raised prolactin
hypothyroidism
stalk lesions (iatrogenic, road accident)
prolactinoma
what are the female clinical signs and symptoms of a prolactinoma
early presentation galactorrhoea (lactation) menstrual irregularity ammenorrhoea infertility
what are the male clinical signs and symptoms of prolactinomas
late presentation impotence visual field abnormality heachache (when very big, LATE presentation) anterior pituitary malfunction
what are the investigations into prolactinoma
serum prolactin concentration (should be raised) MRI pituitary (micro/macroprolactinoma, pituitary stalk, optic chiasma) visual fields pituitary function tests (other hormones affected)
what is the treatment for a prolactinoma
dopamine agonists- cabergoline
surgery not right treatment
what are the side effects of dopamine agonists
nausea/ vomiting
low mood
fibrosis (rare)
what is important to warm women of when starting a dopamine agonists
common to get pregnant very shortly after starting them - menstruation regained
what causes acromegaly
GH excess due to pituitary adenoma
what are the signs of acromegaly
giant (before epiphyseal fusion)
thickened soft tissues (skin, large jaw, sweaty, large hands)
snoring/ sleep apnoea (thickened nasopharynx)
hypertension (heart), cardiac failure
headaches (vascular)
diabetes mellitus (stress hormone so will increase BG)
local pituitary effects (visual fields, hypopituitarism)
early CV death
colonic polyps and colon cancer
what is IGF 1
molecule whos production is stimulated by GH, how GH has its effect on tissues
how do you diagnose acromegaly
IGF1
glucose tolerance test (should make GH to less than 0.4 micro grams, if not/ or if paradoxical rise then acromegaly
visual field, CT or MRI pituitary scan, pituitary function tests
what is the treatment for acromegaly
1st line- pituitary surgery (transphenoidal route, or from above via craiotomy)
external radiotherapy to pituitary fossa
then retest GTT
if not improved:
drugs, radiotherapy, repeat surgery if curable
growing round what structure makes a macroadenoma hard to surgically remove
the carotid artery
what drugs can be used to treat acromegaly
- somatostatin analogues
(sanostatin LAR/ lanreotide)
reduces GH in most patients
can cause tumour shrinkage or be used pre op to relive headaches
- dopamine agonists
(cabergoline, workes in 10-15% of patients, better id co secreting prolactin) - GH antagonists (pegvisomant- block GH activity, 85% response rate, tumour size doesnt decrease, IGF 1 conc decreases)- last line therapy
what are the side effects of somatostatin analogues
local stinging short term: -flatulence -diarrhoea -abdo pains
long term
-gallstones (stops gall bladder contraction)
what should be included in an acromegaly follow up
safe GH and IGF 1 levels check pituitary hormones cancer surveillance: colon and tubulo-villous adenoma CV risk factors (BP, lipids, glucose) sleep apnoea
is surgery the first line of treatment for acromegaly
yes
what is the 1st line treatment for prolactinoma
dopamine agonists
what causes an acromegalic headache
vascular
