Prolactinoma Flashcards
def
a benign tumour (adenoma) which secretes prolactin
aetiology
majority are caused by sporadic mutation of pituitary cells which stimulates the increased cellular growth rate
epi
most common type of pituitary adenoma
women>men at child-bearing age
risk factors
female
child-bearing age
history
in women
1 amenorrhoea or oligomenorrhoea (missing periods or infrequent periods)
2 galactorrhoea
2 infertility
in men
1 erectile dysfunction
2 loss of libido (in women too)
why does high prolactin cause infertility
inhibits ovulation
why does high prolactin cause loss of libido
hyperprolactinaemia causes secondary hypogonadism
examination
1 gallactorrhoea
2 visual changes
-bitemporal hemianopia caused by large pituitary tumour pressing on the optic chiasm
investigations
1 bloods
-high prolactin
2 imaging (pituitary MRI)
-asymptomatic pituit
why is in important to confirm an elevated prolactin before ordering a pituitary MRI
it is common to find asymptomatic pituitary adenomas in the normal population
management
primary goal of management is to reduce prolactin levels to restore ovulation in women and to normalise testosterone and sexual function in men
additionally management to reduce the size of the tumour which may be causing visual defects
1 dopamine agonists such as cabergoline are first line
-inhibit prolactin
2 patients who do not respond to dopamine agonists are considered dopamine resistant and instead undergo surgery for prolactinoma resection
management of a pre-menopausal woman
asymptomatic - observations
symptomatic:
1 first line is a dopamine agonist (cabergoline)
2 second line is COCP, this is for woman with small prolactinomas presenting only with menstrual irregularities and no desire to become pregnant
3 prolactinoma resection
management of a men
1 first line is a dopamine agonist (cabergoline)
2 prolactinoma resection
complications
1 visual defects
-bilateral hemianopia
2 anterior pituitary failure and/or diabetes insipidus if surgery is complicated
prognosis
good prognosis
a 45y/o man presents with loss of libido and erectile dysfunction. O/E he has mild bilateral gynaecomastia and normal testes. He also has bi-temporal hemianopia. Bloods show high prolactin. Bloods also show low testosterone, LH+FSH.
prolactinoma
a 27y/o woman presents with amenorrhoea. She has been taking the COCP for the last 11yrs but has stopped this 11 months ago. O/E she has bilateral galactorrhoea. Bloods show raised prolactin levels. She has low-normal LH+FSH levels.
prolactinoma
what does prolactin stimulate
lactation
how does hyperprolactinaemia lead to hypogonadism
inhibits gonadotrophin releasing hormone which leads to reduced gonadotrophins (LH+FSH) and therefore reduced oestrogen or testosterone
where is prolactin released from
anterior pituitary
what inhibits prolactin release
dopamine
where is dopamine produced
hypothalamus
what drugs can cause hyperprolactinaemia
metoclopramide
