Pituitary Tumours - Non functional adenomas

Question 1

microadenoma vs macroadenoma?

Answer 1

micro = <1cm
macro = >1cm

Question 2

what are some possible complications of a non-functional pituitary adenoma which causes the pituitary to be too big?

Answer 2

compression of optic chiasm

compression of certain cranial nerves (3,4,6)

Question 3

what are some complications of non-functional pituitary adenoma which causes the pituitary to be too small?

Answer 3

hypoadrenalism
hypothyroidism
hypogonadism
diabetes insipidus
GH deficiency

Question 4

what sight problem is caused by pituitary tumour compressing on optic chiasm?

Answer 4

bitemporal hemianopia

Question 5

what physiological things can cause increased prolactin?

Answer 5

breast feeding
pregnancy
stress
sleep

Question 6

wht drugs can cause raised prolactin?

Answer 6

dopamine antagonists (metoclopramide)
antipsychotics (phenothiazides)
antidepressants, oestopgens, coccaine

Question 7

name 3 pathological causes of raised prolactin?

Answer 7

hypothyroidism
stalk lesions (iatrogenic, car accident, tumour pressing on tumour etc)
prolactinoma

Question 8

what are some clinical signs and symptoms in females of raised prolactin?

Answer 8

early presentation
galactorrhoea
menstrual irregularity
amenorrhoea
infertility

Question 9

what are the male symptoms and signs of raised prolactin?

Answer 9

late presentation
impotence
visual field abnormal
headache
anterior pituitary malfunction

Question 10

investigations for prolactinoma?

Answer 10

serum prolactin concentration
MRI of pituitary
visual field (possible bitemporal hemianiopia)
pituitary function tests

Question 11

what features can be seen on MRI in prolactinoma?

Answer 11

macroprolactinoma or macroprolactinoma

Question 12

what are the medical treatments for prolactinoma?

Answer 12

dopamine antagonists

• mainly cabergoline (dostinex)
• quinagolide (norprolac)
• bromocriptine

Question 13

what are the side effects of dopamine agonists?

Answer 13

nausea/vomiting
low mood
fibrosis (heart valves/retroperitoneal)

Question 14

what are the features of acromegaly?

Answer 14

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

Question 15

what causes acromegaly?

Answer 15

GH excess

Question 16

how is acromegaly diagnosed?

Answer 16

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

Question 17

how is acromegaly treated?

Answer 17

pituitary surgery
external radiotherapy to pituitary fossa
retest GTT (needs retreatment if GH >1)
- drugs
- radiotherapy
- repeat surgery if curable

Question 18

what is the most successful treatment for acromegaly?

Answer 18

surgery

- works best for microadenoma rather than macro

Question 19

name 3 drugs used for acromegaly?

Answer 19

somatostatin analogues (octreotide)
dopamine agnonists
GH antagonists

Question 20

what do somatostatin analogies do?

Answer 20

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

Question 21

what are the side effects of somatostatin analogues?

Answer 21

local stinging
short term
- flatulence
- diarrhoea
- abdominal pains
long term
- gallstones

Question 22

name 3 somatostatin analogues used in acromegaly?

Answer 22

sandostatin LAR
lanreotide autogel
pasireotide LAR

Question 23

how are dopamine agonists delivered and how effective are they in acromegaly?

Answer 23

cabergoline up to 3g weekly
works in 10-15%
better in co-secreting prolactin

Question 24

how are GH antagonists delivered and what does it do?

Answer 24

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

Question 25

what is included in acromegaly follow up?

Answer 25

check GH
- <0.4 post GTT
- <2 random
check pituitary hormones (esp thyroid)
cancer surveillance
cardio risk factors
sleep apnoea