Pituitary Tumour Flashcards
What are the 5 cell types in the anterior pituitary gland and what hormones do they make?
What do tumours of the 5 cell types make?
What are the radiological (MRI) ways to classify a pituitary tumour?
Size
Microadenoma <1cm (10mm)
Macroadenoma >1cm (10mm)
Sellar or suprasellar
Compressing optic chiasm or not
Invading cavernous sinus or not
How can you classify a pituitary tumour by function?
Excess secretion of a specific pituitary hormone
eg prolactinoma
No excess secretion of pituitary hormone (Non Functioning Adenoma)
What ways can pituitary tumours be classified?
Radiological (MRI)
Function
Benign or Malignant
Pituitary carcinoma very rare (<0.5% of pituitary tumours)
Mitotic index measured using Ki67 index – benign is <3%
Pituitary adenomas can have benign histology but display malignant
behaviour
What happens in Hyperprolactinaemia?
What are Prolactinomas?
Commonest functioning pituitary adenoma
Usually serum [prolactin] >5000 mU/L
Serum [prolactin] proportional to tumour size
How do Prolactinomas present?
Menstrual disturbance
Erectile dysfunction
Reduced libido
Galactorrhoea
Subfertility
What are other causes of an elevated prolactin?
What should you do once you have confirmed a true pathological elevation of serum prolactin?
Organise a pituitary MRI
Treatment of prolactinoma?
How do dopamine receptor agonists reduce prolactin and shrink prolactinomas?
What happens if there is excess GH?
Gigantism = children
Acromegaly = adults
How is acromegaly presented?
Often insidious presentation – mean time to diagnosis from onset of symptoms = 10y
What are the mechanisms of growth hormone action
How can acromegaly be diagnosed?
How can acromegaly be treated?
What are the presentations of Cushing’s syndrome
What is Cushing’s syndrome
Occurs due to an excess of cortisol or other glucocorticoid
What are the causes of Cushing’s syndrome?
Causes are ACTH dependent or independent
What are the ATCH dependent causes Cushing’s syndrome?
Cushing’s disease (corticotroph adenoma)
Ectopic ACTH (lung cancer)
What are the ACTH independent causes of Cushing’s syndrome?
Taking steroids by mouth (common)
Adrenal adenoma or carcinoma
Cushing’s syndrome vs Cushing’s disease?
Cushing’s syndrome = excess cortisol
Cushing’s disease is due to a corticotroph adenoma secreting ACTH
How to investigate Cushing’s disease?
What should be done after hypercortisolism is confirmed?
Measure ACTH
If ACTH high, pituitary MRI ACTH dependent
What are problems caused by Non-Functioning Pituitary Adenomas?
Don’t secrete any specific hormone
Often present with visual disturbance (bitemporal hemianopia)
Can present with hypopituitarism
Serum prolactin can be raised (dopamine can’t travel down pituitary stalk from hypothalamus)
Trans-sphenoidal surgery needed for larger tumours, particularly if visual disturbance
