Prolactinoma

Question 1

what is it?

Answer 1

physiologically dopamine inhibits the release of prolactin by the pituitary
prolactinoma is a prolactin secreting tumour (normally when prolactin is over 5000)

Question 2

what causes raised prolactin?

Answer 2

physiological 
- breast feeding 
- pregnancy 
- stress 
- sleep 
drugs
- dopamine antagonists e.g. metoclopramide 
- antipsychotics e.g. phenothiazines 
- antidepressants e.g. TCA, SSRIs 
- other, oestrogens, cocaine 
pathological 
- hypothyroidism 
- stalk lesions - iatrogenic or road accident
- prolactinoma

Question 3

how does it present in females?

Answer 3

early presentation
galactorrhoea 
menstrual irregularity 
amenorrhoea 
infertility

Question 4

how does it present in males?

Answer 4

late presentation
impotence
visual field abnormality
anterior pituitary malfunction

Question 5

how is it investigated?

Answer 5

serum prolactin concentration - is it too high
MRI pituitary - features to look for, is it oversized
- microprolactinoma (<1cm)
- macroprolactinoma (>1cm)
- pituitary stalk
- optic chiasma
visual fields - bitemporal hemianopia (not homonymous hemianopia)
pituitary function tests - are other hormones affected - is there a deficiency in other pituitary hormones

Question 6

how is it managed?

Answer 6

dopamine agonists
bromocriptine - 3 times per day oral
Quinagloide (norprolac) once per day oral
Cabergoline (Dostinex) - usually used - once to twice per week oral (lease side effects)
side effects
- nausea/vomiting
- low mood
- potential fibrosis (heart valves and retroperitoneal)