pathophysiology Flashcards
what is acromegaly a result of?
excess growth hormone
how common is acromegaly?
- Rare – approx. 3-4 people in every million
what is the aetiology of acromegaly?
- Most often caused by a benign pituitary tumour – can also be caused by non-endocrine tumour secreting GH
- Further divided into micro and macroadenomas (macro is most common)
- Some genetic link
are men and women affected the same with acromegaly?
yes - even split
when is acromegaly onset?
often slow and diagnosed in middle age
what are signs of acromegaly?
- Change in facial features – widening of bridge of nose, thick lips, protruding jaw and bone, macroglossia (enlarged tongue), teeth separation
- Headaches and visual disturbance – tumour
- Deeper voice
- Skin tag, excessive sweating and mild hirsutism in women (excessive growth of hair – male like patterns – usually dark and coarse)n
- Joint pain and carpal tunnel syndrome (pressure on nerve on wrist causing numbness and tingling)
- Hypertension and diabetes – extra strain
what investigations are done for acromegaly?
- Routine bloods – glucose, lipids, bone profile
- IGF-1 to exclude acromegaly if normal
- Check thyroid, prolactin, gondal and adrenal hormones – if one is abnormal you are at increased risk of others being abnormal)
- MRI to assess tumour
- CT is non endocrine tumour is suspected
- Cardiac workup – ECG, echo
- Thyroid ultrasound
what treatment is used in acromegaly?
Treatment: usually in combination
- Endoscopic trans-spinodal surgery first line with radiotherapy as an adjuvant
- Somastatin analogues eg octreside – decrease tumour size and manage symptoms
- Dopamine agonists such as bromocriptine – suppress GH hypersecretion
what is first presentation of prolactinomas?
- Usual presentation is raised prolactin – it is raised in lots of other states too ( drugs – spironolactone, NSAIDs, anti-psychotics, stress)
- Women more commonly present with irregular/ absent menstruation, galactorrhoea (milky nipple discharge unrelated to normal milk production of breast feeding), reduced libido, hirsutism
- Men have more subtle associated symptoms: erectile dysfunction, galactorrhoea, reduced beard growth, reduced libido – often presents late with osteoporosis
what symptoms do large prolactinomas tumour present as?
headaches and visual disturbances
what treatment is used in prolactinomas?
cabergoline (dopamine agonist)
what are the side effects of cabergoline?
can cause severe issues with impulse control and sleepiness
what size is a micro prolactinoma?
<1cm
what size is a macro prolactinoma?
1-4cm
what is a giant prolactinoma?
> 4cm
what condition is common following prolactinoma?
- Osteoporosis is common – around 30% lose bone density – hypogonadism and oestrogen and testosterone is required for bone mass
what does luteinising hormone do?
acts on ovaries and testes
- Adrenal gland maturation
what does LH deficiency cause in childhood?
delayed/ no puberty
what does LH deficiency do in women?
menopausal, hirsutism
what does LH deficiency do to men?
regression of sex, loss of muscle, erectile dysfunction
what does hyper LH do to a child?
early puberty, early secondary sexual characteristics
what are the complications of acromegaly?
cardiomegaly, hypotensive, T2DM – increased insulin resistance, bitemporal hemianopia (each vision field is missing outer sections on both sides), impaired glucose tolerance, colo-rectal cancer, osteoarthritis
what has an inhib effect on prolactin?
dopamine
what inhibits LH and FSH secretion?
prolactin
