Hyperprolactinaemia, Acromegaly - booklet Flashcards
1
Q
What to exclude first in hyperprolactinaemia?
A
- Pregnancy
- Full medication history - dopamine antagonists eg anti-emetics, antipsychotics
- Profound hypothyroidism
- PCOS
2
Q
What suggests prolactinoma on test results?
A
- Prolactin levels greater than 5,000 iU/L suggests active secretion rather than stalk effect from non-functioning adenoma
3
Q
Microprolactinoma
A
- Most common pituitary tumour
- Seen more in women
- Typically present with menstrual disturbance, galactorrhoea, infertility
4
Q
Distinguishing PCOS from microprolactinoma
A
- Presence of androgenic symptoms
- Less elevated prolactin (less 1000 miU/L)
- Absence of pituitary lesion on MRI
5
Q
Macroprolactinoma
A
- More than 1cm and can be very large
- Prolactin levels typicall more than 5,000 miU/L
- When levels extremely high, immunoassay can incorrectly give lower results (Hook effect) so it may be necessary to dilute sample to achieve accuracy
6
Q
Treatment prolactinomas
A
- D2 agonists - Cabergoline or Bromocriptine
- Cabergoline once/twice weekly, better tolerated usually than bromo
7
Q
Side effects D2 agonists
A
- Nausea
- Postural hypotension
- Rarer psychiatric disturbance
8
Q
What happens to macroprolactinomas as they shrink sometimes?
A
- CSF leak occurs due to rapid reduction in size
- Potential risk of meningitis
9
Q
Problem with high cumulative dose of dopamine agonists
A
- Cardiac valve abnormalities in Parkinsons disease
- But this is not a concern in prolactinoma doses
- Cardiac symptoms should be investigated though with an echo if on D2 agonists
10
Q
What causes acromegaly?
A
GH secreting pituitary tumour
11
Q
Risk of leaving acromegaly untreated
A
Increase risk of premature death from CV disease
Increase risk of bowel cancer
12
Q
Clinical features acromegaly
A
- Increase size hands and feet
- Facial features coarser
- Frontal bossing forehead
- Protruding chin
- Widely spaced teeth
Soft tissue swelling:
* Enlarged tongue and soft palete
* Sleep apnoea
* Puffiness hands +/- carpal tunnel syndrome
Whole body:
* Sweating
* Headaches
* HTN
* Diabetes mellitus
13
Q
Test for acromegaly
A
- OGTT - failure to suppress GH
- IGF-1- elevated
14
Q
Some acromegaly tumours secrete…
A
- Prolactin sinultaenously as they share same cell origin
- This may be elevated too
15
Q
Imaging acromegaly
A
- MRI pituitary gland
- Microadenomas may need contrast to see
- Increasing role of functional imaging
16
Q
Management for acromegaly
A
- Surgery
- With micro, high chanve surgical remission (complete gone)
- With macro, chance is only 60%
- Medical treatment
- Radiotherapy
17
Q
Medical treatment for acromegaly
A
- Somatostain analogue - Monthly injections
- GH receptor blockers
18
Q
Radiotherapy for acromegaly
A
- External beam or stereotactic radiotherapy (gamma knife)
- STRT provides targeted treatment at higher dose - BUT only suitable for lesions far away from optic chiasm
19
Q
Long term side effects radiotherapy for acromegaly
A
- Gradual hypopituitarism
- Cerebrovascular disease
20
Q
Monitoring acromegaly post surgery
A
- Repeat OGTT
- Long term follow up to ensure GH and IGF-1 controlled & exclude recurrence
- Periodic colonoscopy screening considered due to increase bowel cancer risk
- Assess for sleep apnoea, diabetes, CV disease and symptoms of recurrence
21
Q
Non functioning pituitary adenomas often present with…
A
- Visual field loss
- HEadache
- Hypopituitarism
22
Q
Treatment for non-functioning adenoma
A
- Surgery - transphenoidal if visual field defect or threat to vision
23
Q
Causes of hypopituitarism
A
- Pituitary adenoma
- Inflammatory and ilfiltrative disorders (Diabetes insipidus related)
- Traumatic brain injury
- Radiotherapy
24
Q
Hypopituitarism symptoms
A
- Non specific
- Lethargy
- Weight gain
- Sexual dysfunction
25
Medical emergency presentations of pituitary adenoma
* Hypo-adrenal crisis with
* Hyponatraemia
* Hypotension
26
Investigation for hypopituitarism
* Exclude adrenal insufficiency
27
Treatment hypopituitarism
* ACTH deficiency - Hydrocortisone
* TSH deficiency - Thyroxine
* Gonadrotrophin deficiency - Men testosterone, women oesttogen and progesterone (COCP or HRT)
* GH - GH sc injection if clinical benefit
28
Cushing disease characteristsics
* Central obesity
* Dorso-cervical fat pad
* Increased roundness of face
Often have:
* Red face (plethora)
* Thin skin
* Easily bruising
* Proximal myopathy
29
Associated diseases with Cushings
* HTN
* Premature osteoporosis
* Diabetes mellitus
30
What happens if Cushings is left untreated?
Significant morbidity and has 5yr mortality rate of 50%
31
Investigations for Cushings
* Alcoholism and severe depression can cause Cushingoid (pseudocushings) so screen for this
* 24hr urine free cortisol
* Low dose dexamethasone supression test
* Overnight dexamethasone supression test
* Late night salivary cortisol
32
Results for investigations Cushings
* 24hr UFC elevated
* Failure to suppress cortisol to less than 50nmol/L after LDDST or overnight suggests Cushing syndrome
* Late night salivary cortisol - elevated
33
3 causes of Cushings
* Pituitary
* Adrenal
* Ectopic ACTH
34
What suggests ectopic ACTH?
* Hypokalaemia
* History of smoking
* Weight loss
Lung cancer or another malignancy
35
What suggests adrenal tumour?
* Accelerated hirsutism (hair)
* ACTH low - negative feedback from high cortisol levels from adrenals
36
ACTH normal or high
* Suggests ectopic ACTH or pituitary
37
CRH response in Cushings
* If give CRH:
* Exaggerated response rise in ACTH and cortisol in pituitary lesion
* Flat response in ectopic
38
HDDST results Cushings
* Suppresses pituitary Cushings disease
* Does not suppress ectopic
39
What should we do if results suggest pituitary cause?
* MRI pituitary
* If no lesion seen do inferior petrosal sinus sampling
* Can confirm central ACTH secretion by showing clear gradient between central and peripheral ACTH levels after CRH injection
40
What should we do if we suspect ectopic ACTH?
* Whole body CT and PET imaging
* Carcinoma elsewhere often in thorax
41
# uspect
* If adrenal - laparoscopic adrenalectomy
* Ectopic - treat underlying malignancy and medically control cortisol
* Cushing disease - transphenoidal removal, can use Ketoconazole and Metyrapone and radiotherapy
42
43
