pituitary tumours

Question 1

what are the 5 types of anterior pituitary cells

Answer 1

somatotrophs
lactotrophs
thyrothrophs
gonadotrophs
corticotrophs

Question 2

what can a somatotroph tumour cause

Answer 2

acromegaly

Question 3

what can a lactotroph tumour cause

Answer 3

prolactinoma

Question 4

what can a thyrotroph tumour cause

Answer 4

tshoma (very unusual)

Question 5

what can a gonatroph tumour cause

Answer 5

gonadotrophinoma(unusual)

Question 6

what can a corticotroph tumour cause

Answer 6

cushings disease/ corticotroph adenoma

Question 7

how to classify pituitary tumours

Answer 7

1. radiological:
   size: microadenoma <1cm
   macroadenoma>1cm
   sella/suprasella
   compressing optic chiasm?
   invading cavernous sinus
   functioning or not?: secretions
   benign/malignant:

Question 8

what does hyperprolactinaemia effect the gonads

Answer 8

prolactin binds to prolactin receptors on kisspeptin neurone
kisspeptin release is inhibited
gnrh neurones are not able to travel down hypophyseal portal circulation
decrease in downstream gnrh,lh,fsh,t,oest
causes oligo amennorrhoea
low libido
infertility
osteoporosis
(symptoms of secondary hypogonadism)

Question 9

what are prolactinomas

Answer 9

commonest functioning pituitary adenoma

>5000 mu/l serum prolactin

Question 10

presntation of prolactinoma

Answer 10

menstrual disturbance
erectile dysfunction
reduced libido
galactorrhoea
subfertility

Question 11

other causes of elevated prolactin

Answer 11

pregnancy/breastfeeing
stress/exercise/seizures/venepuncture
pathological - hypothyroidism,pcos,chronic renal failure
lactrogenic - anti psychotics, ssris, antiemetics, high dose oestrogen, opiates

Question 12

what is a macroprolactin

Answer 12

sticky prolactin
polymeric form of prolactin - antigen antibody complex of prolaction and igG
recorded as elevated prolactin

Question 13

what can the stress of venepuncture cause

Answer 13

elevated prolactin

use cannulated prolactin series instead

Question 14

once confirmed prolactinoma what should you do

Answer 14

organise pituitary mri

Question 15

treatment of prolactinoma

Answer 15

medical!
dopamine recpetor agonist - Cabergoline
safe in preg
shrinks prolactinoma

Question 16

what are some symptoms/sign of acromegaly

Answer 16

sweatiness
headache
macroglossia
prominent nose
large jaw - prognathism
increased hand and feet size
snoring/obstructive sleep apnoea
hypertension
impaired glucose/ diabetes mellitus
(increased cvd)

Question 17

what are the mechanisms of GH?

Answer 17

direct effects - binds to receptors on bone

gh also travels to liver to screte igf1 and igf2(fetal growth)

Question 18

diagnosis of acromegaly

Answer 18

gh is pulsatile
can do an igf1 test - elevated
then oral glucose tolerance test- in acromegaly gh increases after oral glucose load

Question 19

treatment of acromegaly

Answer 19

trans sphenoidal pituitary surgery
can use medical beforehand to shrink tumour
somatostatin analogues - octreotide
dopamine agonists e.g cabergoline
aim is to dcrease cvd risk
radiotherapy?

Question 20

what are the signs and symptoms of cushins

Answer 20

red cheeks
fat pads
moon face
easil bruising
depression
impaired glucose tolerance

Question 21

what is cushings syndrome cause by?

Answer 21

• excess of cortisol or other glucocorticoid
  acth dependent:
  adenoma of corticotrophs - cushings disease
  ectopic acth - lung cancer
  acth independent:
  steroid use e.g in asthma ,rheum arth
  adrenal ademona/carcinoma

Question 22

how to investigate cushings disease

Answer 22

elevation of 24h urine free cortisol
salivary/blood test at night
failure to supress cortisol after dexamethasone

Question 23

after confirming hypercortisolism what should you do

Answer 23

measure acth

if high - acth dependent

Question 24

what is a feature of non functioning pituitary adenoma

Answer 24

bitemporal hemianopia
can cause hypopituitarism
sometimes high prolactin
trans sphenoidal surgery needed