Pituitary Disorders Flashcards
What is the term for a tumour that is not cancer/benign tumour of glandular epithelial origin?
Adenoma
What are the 4 ways we asses patients with pituitary disorders?
-Clinical
-Biochemical
-Imaging
-Visual fields
What are clinical assessments?
History and examination
How might a pituitary tumour present clinically?
The adenoma affect local structures putting pressure on them:
This may cause vision loss (tunnel vision) or headaches
Pituitary may abnormally produce hormones:
Hypo-secretion
Hyper-secretion
How can superior growth of a pituitary tumour affect a patient?
Causes visual field loss
Optic chiasm is superior to pituitary
The pituitary tumour squashes the optic chiasm
What is the term given to describe tunnel vision/visual field loss?
Bitemporal hemi-anopia
Which direction of pituitary tumour growth can cause Bitemporal hemi-anopia?
Superior growth
How can lateral growth of a pituitary tumour affect a patient?
Causes pain (thunderclap headaches) and can cause Double vision (Diplopia)
Diplopia caused by nerves III and IV being squashed by tumour (responsible for eye movement)
Pain caused by nerves (Va,b) being squashed or blood vessels being squashed causing haemorrhaging
How can a pituitary tumour cause Hypopituitarism?
The tumour can block the tropic hormones that are produced by the hypothalamus from ever reaching the pituitary gland. This can have significant affects
What tropic hormones can a pituitary tumour block from ever reaching the pituitary?
GHRH Means less GH made
GnRH Means less LH and FSH made
TRH Means less TSH made
CRH Means less ACTH made
PIH/Dopamine Means MORE prolactin is made
How would blockage of GHRH by a Pituitary tumour affect a patient?
Deficiency of GH
Short stature in children (long bone growth not stimulated)
Reduced quality of life in adults (muscle and bone mass loss, reduced ability to exercise, increased visceral fat)
How would blockage of GnRH by a Pituitary tumour affect a patient?
Gonadotropin deficiency so deficient LH and FSH
Delayed puberty in children
Loss of secondary sexual characteristics in adults
(Loss of periods = early sign for women)
How would blockage of TRH by a Pituitary tumour affect a patient?
Deficiency in TSH
So low thyroid hormone levels
Affects metabolism
Causes weight gain, tiredness, slow pulse, coldness
How would blockage of CRH by a Pituitary tumour affect a patient?
Deficiency of ACTH
Low cortisol
Causes tiredness, dizziness, low BP, low sodium
CAN BE LIFE THREATENING
What happens with Hyperpituitarism due to a pituitary tumour?
The tumour causes the anterior pituitary to produce excess of the hormones that it produces
What are the 3 common hormones which are produced in excess when a pituitary tumour causes Hyperpituitarism?
Prolactin
GH (Growth Hormone)
ACTH (Adrenocorticotropic Hormone)
How can we biochemically assess for pituitary disease involving the Thyroid axis, Prolactin axis and Gonadal axis?
Basal blood tests (use amino assays)
For thyroid axis testing for free circulating thyroxine levels
Prolactin axis testing for serum prolactin levels
For gonadal testing for LH, FSH, Testosterone (Men) and Oestradiol (women) levels
How do we biochemically assess for pituitary disease involving the HPA (Hypothalamic-Pituitary-adrenal) axis and GH axis?
Dynamic blood test (continuous measurements)
Cortisol levels
GH/IGF-1 levels
If IGF-1 is low it shows GH is deficient
What 2 types of tests are done in the dynamic assessment of HPA and GH axes?
Stimulation tests (if hormone deficiency suspected try stimulate it)
Suppression tests (if hormone excess suspected try and decreases it)
What test is done if thought Adrenal axis is in deficiency?
SynACTHen test
Insulin stress test
What test is done if Adrenal axis is thought to be in excess?
Dexamthasone suppression test
What test is done if GH axis is thought to be in deficiency?
Insulin stress test (since insulin stimulates GH)