Pituitary tumours Flashcards
What are the 5 types of pituitary tumours?
GH - Acromegaly //
Prolactin - Prolactinoma //
TSH - TSHoma //
Gn - gonadotrophinoma //
Corticotrophs - Cushing’s Disease (corticotroph adenoma)
What are the two radiological classifications of pituitary tumours?
Size (microadenoma <1cm, macroadenoma >1cm) // Location - sellar (compressing optic chiasm) or suprasellar (invading cavernous sinus)
What is the functional classification of pituitary tumours?
Excess secretion (functioning adenoma),
no excess secretion (non-functioning adenoma), can change other hormones of the gland
Are pituitary tumours more likely to be malignant or benign
Benign
How would you assess whether a pituitary tumour is benign or malignant?
Mitotic index (Ki-67), very rarely malignant
pituitary adenomas can have benign histology but malignant behaviour (affect surrounding structures)
What are the presentations of prolactinomas?
Menstrual disturbance, low libido, subfertility, galactorrhea
this is to prevent reproduction when there is lack of nutrition
mechanism of prolactinomas
Elevated levels of prolactin inhibit kisspeptin release therefore GnRH is not released nor FSH & LH (very common SAQ)
What are 2 physiological non-cancerous causes of elevated prolactin?
Pregnancy/Breastfeeding, Stress (exercise, venepuncture), nipple/chest wall stimulation
What are three pathological causes of elevated prolactin?
PCOS, Chronic Kidney Failure, Primary Hypothyroidism
What 5 types of drugs cause elevated prolactin?
Antipsychotics, SSRIs, Anti-emetics, high dose oestrogen, opiates
What is the first-line treatment for prolactinomas?
dopamine receptor agonists (cabergoline more specific)
bromocriptine, original
How do dopamine receptor agonists work?
Mimic dopamine, binds to D2 receptors on lactotrophs which inhibits release of prolactin (again easy SAQ)
What 2 symptoms do patients with acromegaly complain of?
Sweatiness and Headache
Aim of prolactinoma treatment
decrease serum prolactin and shrink prolactinoma
What are the 4 presentations of acromegaly?
Coarsening of facial features: macroglossia,
large jaw - prognathism,
increased hand and feet size,
sleep apnoea
What are two internal conditions that are concerned with acromegaly?
Hypertension, Impaired glucose tolerance (T2DM)
How do you diagnose acromegaly?
- Give oral glucose load, observe a paradoxical rise in GH (normally GH levels drop, but in acromegaly GH levels rise)
- elevated serum IGF-1
What is the first-line treatment of acromegaly?
Trans-spehnoidal pituitary surgery, break through sphenoidal sinus to access pituitary gland
What medication can be given for acromegaly?
Somatostatin Analogues (octreotide), shrink tumour
Dopamine Agonists (cabergoline)
What are some of the key symptoms in Cushing’s syndrome?
Proximal Myopathy (muscle weakness),
poor wound healing, not synthesising protein properly
purple striae
obese, pendulous abdomen
osteoporosis, stop making bones
impaired glucose tolerance and hypertension
What are the two types of causes of Cushing’s syndrome?
ACTH dependent (too much ACTH)
independent (ACTH unimpaired)
What are two examples of causes for each type of cause?
ACTH dependent - Cushing’s disease (corticotroph adenoma) and Ectopic ACTH (lung cancer) //
ACTH independent - steroids by mouth, adrenal adenoma
What is the difference between Cushing’s syndrome and Cushing’s disease?
Cushing’s syndrome is excess cortisol,
Cushing’s disease is corticotroph adenoma secreting ACTH
How would you diagnose Cushing’s disease in 3 ways?
Elevated 24h urine free cortisol,
Elevated late night cortisol (use saliva or blood test),
Failure to suppress low dose dexamethasone (increased cortisol secretion)
