pituitary axis/prolactinoma/non-functioning pit. adenoma/acromegaly

Question 1

what are the 7 hormones of anterior pituitary

Answer 1

ACTH
TSH
GH
PRL
FSH
LH
MSH

Question 2

what are the 2 hormones of posterior pituitary

Answer 2

oxytocin
ADH

Question 3

what are the axises of the pituitary

Answer 3

Question 4

what is a paired hormone

Answer 4

ie ACTH and cortisol for the steroid axis

Question 5

what are you looking for in a pituitary blood test

Answer 5

TSH
fT4
FSH
testosterone
GH
IGF-1
Prolactin

Question 5

what are you looking for in a pituitary blood test

Answer 5

TSH
fT4
FSH
testosterone
GH
IGF-1
Prolactin

Question 6

what is the insulin stress test

Answer 6

it is a stimulation test that induces hypoglycaemia to measure growth hormone

Question 7

which cranial nerve is affected by pituitary tumour / enlargement

Answer 7

2
optic nerve

Question 8

what is a non-functioning pituitary adenoma

Answer 8

its growing large but secretions are in line

it can get:
too big - compression of potion chiasm / other structures

too small - hypoadrenalism,hypothyroidism and hypogonadism

Question 9

why can you get sight problems with pituitary pathology

Answer 9

if mass hits the optic chiasma - can affect nerves which misinterprets light information - so need to check visual fields

Question 10

what is the disease most associated with optic chiasm compression

Answer 10

bitemporal hemianopia

Question 11

how to manage a non functioning pituitary adenoma

Answer 11

transphenoidal surgery
and replace hormones

Question 12

what are causes of prolactinoma

Answer 12

physiological:
breast feeding
pregnancy
stress/anxiety
sleep

pharmacological:
dopamine antagonists
antipsychotics
antidepressants ie risperidone
other eg oestrogen

pathological:
hypothyroidism
stalk lesions - iatrogenic / rtc
prolactinoma

Question 13

what is relevant about the prolactin hormone

Answer 13

it is the only one under inhibitory control - dopamine

Question 14

what is this

Answer 14

and this is what is looks like pathologically

Question 15

signs and symptoms of prolactinoma

Answer 15

in Female:
early presentation
galactorrhea
menstrual irregularity
ammenorrhoea
infertility

in Male:
late presentation
impotence
visual field abnormal
ant. pit. malfunction

Question 16

ivx for prolactinoma

Answer 16

serum prolactin conc.
MRI of pit.
Visual fields
Pit function tests

Question 17

medical mx prolactinoma

Answer 17

Dopamine agonists

eg cabergoline / dostinex

Question 18

side effects of dopamine agonists

Answer 18

nausea vomitting
low mood
obsessive compulsive behaviour

Question 19

how does acromegaly come about

Answer 19

GH excess

(growth hormone - usually due to a secreting pituitary adenoma)

Question 20

clinical sigs of acromegaly

Answer 20

giant
large hands and feet
outward growth of jaw
increased interdental spacing & macroglossia
oily skin
thickened soft tissue
snoring/ apnea
HPT
headaches (vascular)
DM
local pit. effects
early CV death
colonic problem

Question 21

what does this guy have

Answer 21

acromegaly

Question 22

diagnostic test for acromegaly

Answer 22

too much GH

IGF-1 - age and sex matched

GTT (Glucose tolerance test) - would suspect GH to be suppressed but in acromegaly GH is not suppressed or can even rise

visual fields
pit. function tests

Question 23

tx for acromegaly

Answer 23

pituitary surgery - very effective in a microadenoma

radiotherapy

drugs:
somatostatin analogues ie
Sandostatin LAR
(subcutaneous injection)

dopamine agonists can be used as well ie
Cabergoline

GH antagonists ie
Pegvisomant
(SC injection - binds to GH receptor and blocks GH activity) this is last line in therapy, in this case tumour size does not decrease

Question 24

side effects of somatostatin analogues

Answer 24

flatulence
diarrhoea
abdominal pain
gallstones - long term

Question 25

what are the somatostatin analogues

Answer 25

sandostatin LAR
lanreotide autogel
pasireotide LAR

Question 26

what else do you need to monitor in acromegaly

Answer 26

cancer surveillance
CV risk
sleep apnea

Question 27

Question 28

pathophys. of acromegaly

Answer 28

the abundance of GH circulating results in excessive production of insulin-like growth factor (IGF-1) which is inappropriate for growth

physiologically, GH should be suppressed by somatostatin

excess GH causes metabolic disturbances including T2DM because of insulin resistance

Question 29

main diagnostic test for acromegaly

Answer 29

GLUCOSE TOLERANCE TEST
and if its not suppressed/rised then MRI to check tumour size and shape

Question 30

1st tx for acromegaly

Answer 30

trans-sphenoidal surgery

Question 31

which of the following conditions is associated with pituitary adenoma?

DM
dysphonia
bitemporal hemianopia
homonymous hemianopia
cranial nerve IX X XI palsies

Answer 31

bitemporal hemianopia

Question 32

A 34 year old lady visits her doctor because of galactorrhoea and secondary amenorrhoea. This has been going on for several months and is causing her a lot of stress and inconvenience. She has a background history of high blood pressure, mental health problems and is an ex IV drug abuser. There is no family history of note.

A blood test reveals that she has a serum prolactin level of 950 nmol/l. A scan of her brain / pituitary is normal.

Which of the following is the most likely cause of her hyperprolactinaemia?

Answer 32

Question 33

what is the initial screening test for acromegaly

Answer 33

serum IGF-1

Question 34

why can you get sleep apnea with acromegaly

Answer 34

upper airway obstruction secondary to macroglossia and soft tissue swelling