Clinical Aspects of Pituitary Disease Flashcards
What does primary refer to?
The gland
What does secondary refer to?
The pituitary gland
What does tertiary refer to?
Releasing hormones from the hypothalamic region acting on the pituitary
Function of parathyroid glands
Help to regulate the calcium levels in the blood
What to the adrenal glands help to trigger?
The fight or flight response
If there is a lack of hormone at a primary level, the feedback will make the hormone produce LESS or MORE hormones?
More
Hypersecretion of GH leads to….
Acromegaly
Gigantism
Hypersecretion of ACTH leads to…
Cushing’s disease
Hypersecretion of prolactin leads to….
Hyperprolactinaemia
What causes hypersecretion of hormones?
Tumours
Space occupation of the pituitary gland can lead to what?
Optic chiasmal compression
Presentation of acromegaly
Spade like hands Wide feet / increased shoe size Coarse facial features Thick and large lips and tongue Prognathism Interdental spaces Carpal tunnel syndrome Sweating and oily skin Headache Chiasmal compression DM HTN Cardiomyopathy Sleep apnoea Accelerated OA Colonic polyps and cancer Features of pituitary tumour
What happens in acromegaly due to the excess GH?
Soft tissue overgrowth
Questions to ask yourself if you think it is acromegaly
Can GH be suppressed? Is IGF-1 elevated? Is the rest of pituitary function normal? Is there a pituitary tumour on MRI? Is vision normal?
Presentation of Cushing’s syndrome
Weakness of skin, muscle and bone HTN Heart failure DM Skin atrophy Spontaneous purpura Proximal myopathy Osteoporosis Growth arrest in children Pink striae Facial mooning hirsutism Oedema (non-specific) Central obesity
Why does cushing’s syndrome cause a lot of weakness?
As cortisol is a catabolic hormone
Causes of cushing’s syndrome
ACTH dependent
- pituitary tumour (cushings disease)
- Ectopic ACTH secretion (e.g. lung carcinoid)
ACTH independent
- Adrenal tumour (adenoma or carcinoma)
- Corticosteriod therapy (e.g. for asthma, IBD)
Presentation of hyperprolactinaemia in women
Galactorrhoea 30-80%
Menstrual irregularity
Infertility
Presentation of hyperprolactinaemia in men
Galactorrhoea < 5% Impotence Visual field abnormalities Headache Extraocular muscle weakness Anterior pituitary malfunction
Physiological causes of hyperprolactinaemia
Pregnancy
Lactation
Stress
What drugs can cause hyperprolactinaemia?
DA depleting and DA antagonistic drugs
- anti-emetics
- neuroepileptics
Causes of hyperprolactinaemia
Pregnancy Stress Lactation DA depleting/antagonistic drugs Primary hypothyroidism Pituitary lesions (prolactinoma or pituitary stalk pressure)
Presentation of pituitary hypofunction in adults
Tiredness Weight gain Depression Reduced libido Impotence Menstrual problems Skin pallor Reduced body hair
Presentation of pituitary hypofunction in children
Reduced linear growth
Delayed puberty
What can lack of vasopressin lead to?
Diabetes insipidus
What test is done to detect diabetes insipidus?
Water deprivation test
Differential diagnosis for cranial diabetes insipidus?
Idiopathic Post trauma (including pituitary surgery) Metastatic carcinoma Craniopharyngioma Other brain tumours e.g. germinoma Rare causes e.g. sarcoidosis
What nerves lie in close anatomical relation to the pituitary gland?
Oculomotor Trochlear Opthalmic Abducens Maxillary
Medical Treatment of a prolactinoma
Dopamine agonist
Medical treatment for acromegaly
Somatostatin analogues
GH receptor antagonist
What does pituitary radiotherapy cause?
Hypopituitarism
Benefits of somatostatin analogues in acromegaly
Improves soft tissue overgrowth, sweating, headache and sleep apnoea in most patients
Normalise GH and IGF-1 levels in over 50% of patients
Induce tumour shrinkage in the majority
Reduce morbidity and mortality
What somatostain analogue drugs are used to treat acromegaly and how often are they given?
Octreotide and Lanreotide
Monthly injections of slow release
Side effects of somatostatin analogues
Nausea Cramps Diarrhoea Flatulence Cholesterol gallstones in 20-30% (mostly asymptomatic)
To be classed as a microprolactinoma, what size must it be?
< 10mm
What is a microprolactinoma treated with?
Dopamine agonist
To be classed as a macroprolactinoma, what size must it be?
> 10mm
What is the dopamine agonist used to treat micro-macro prolactinoma?
Cabergoline
Drugs that affect dopamine
Anti-emetics
Anti-psychotics
What puts your prolactin up?
Prolactinoma Stress Seizures Drugs Pregnancy
What visual problem is commonly seen in pituitary problems?
Bitemporal hemaniopia
What can TRH also interfere with?
Prolactin
Who commonly gets hyperparathyroidism?
Middle aged women
What do the levels of FSH/LH do post menopause? Why?
They go UP
As less oestrogen for negative feedback
What is characteristic about the levels of cortisol?
It has a circadian rhythm
When is the nadir of cortisol?
Midnight
When is the peak level of cortisol and what would this be expected to be?
> 300
What does the synacthen test stimulate?
The adrenal gland
What can compression of the pituitary stalk lead to?
Hyperprolactinaemia
What is GH used for in adults?
Bone health
Muscle health
Repair
What does transsphenoidal mean?
Up through the nose
What would be measured if suspect acromegaly?
IGF-1 (more stable to measure than GH)
Glucose tolerance test
Which hormones reduce your sugar?
Cortisol
GH
What is there an increased risk of with increased GH and therefore what is offered?
Bowel cancer
Colonoscopy screening offered
If you have more fat, what does this do to your testosterone levels?
Lowers them
Definition of polycythaemia
An abnormally increased concentration of haemoglobin in the blood, either through the reduction of plasma volume or an increase in cell numbers
Levels of sex hormones / gonadotrophins in Klinefelters XXY
Increased testosterone
Decreased FSH/LH
What is the test for Klinfelters?
Karyotype for XXY
What is testicular feminisation?
Rare disorder where born genetically male but genitals may appear between male and female due to the androgen receptors not responding properly
What is testicular feminisation also known as?
Androgen insensitivity syndrome
What is a main side effect when taking testosterone?
It thickens the blood
What has to be taken into account when taking testosterone in respect to the prostate?
Testosterone can make prostate cancer grow
So when older monitor prostate levels
What is the haematocrit?
The ratio of the volume of red blood cells to the total volume of blood
What could be used to treat very “thickened” blood?
Blood letting/venesection
What is vitamin D’s relationship to calcium?
Vitamin D helps to absorb calcium
Why do you get excessive sweating and oily skin in acromegaly?
Sweat gland hypertrophy
What is raised in acromegaly in 1/3rd of cases and therefore presents as what?
Prolactin
Galactorrhoea
Complications of acromegaly
HTN
DM (>10%)
Cardiomyopathy
CRC
Investigations of acromegaly
- Serum IGF-1 levels
- Confirmation by lack of suppression of GH following documented hyperglycaemia during an oral glucose load
Can do an OGTT
- normal patients = suppressed with hyperglycaemia
- may demonstrate impaired glucose tolerance which is associated with acromegaly
Pituitary MRI may show tumour
Why can GH not be used as an investigation for acromegaly?
GH levels vary during the day
1st line management for acromegaly in the majority of patients
Transsphenoidal surgery
Management of acromegaly
Transsphenoidal surgery
Somatostatin analogues
Pegvisomant (GH receptor antagonist)
Dopamine agonists
Who can external irridation be used in in acromegaly?
Older patient following patients or following failed medical /surgical treatment
Treatment for galactorrhoea
Bromocriptine
