pituitary Flashcards
panhypopituitarism: define the term panhypopituitarism, explain the causes, and recall the signs, symptoms and treatment
define panhypopituitarism
decreased production of all anterior pituitary hormones, or of specific hormones
2 generic causes of hypopituitarism and prevalence
congenital (rare), acquired (common)
usual cause of congenital panhypopituitarism
mutations of transcription factor genes needed for normal anterior pituitary development e.g. PROP1
hormone deficient characteristics of congenital panhypopituitarism
deficient in growth hormone and at least 1 or more anterior pituitary hormones
clinical presentation of congenital panhypopituitarism
short stature, hypoplastic (incomplete development) anterior pituitary gland on MRI
8 causes of acquired panhypopituitarism
tumours (most common), radiation, infection, traumatic brain injury, infiltrative disease, inflammatory (hypophysitis e.g. caused by autoimmune destruction), pituitary apoplexy, peri-partum infarction
2 types of tumours causing acquired panhypopituitarism
hypothalamic (craniopharyngiomas), pituitary (adenomas, metastases, cysts)
effect of radiation on acquired panhypopituitarism, including relative resistance of GH and TSH
can be caused by radiotherapy for cancer: hypothalamic/pituitary damage, with GH being most vulnerable and TSH being relatively resistant
example of infection causing acquired panhypopituitarism
meningitis
what does an infiltrative disease causing acquired panhypopituitarism often involve
pituitary stalk e.g. neurosarcoidosis
causes of pituitary apoplexy causing acquired panhypopituitarism
intra-pituitary haemorrhage, or less commonly infarction
what is the name of peri-partum infarction causing acquired panhypopituitarism
Sheehan’s syndrome
what is panhypopituitarism also called
Simmond’s disease
what is the name of the condition where there is deficient FSH/LH due to panhypopituitarism
secondary hypogonadism
clinical presentation of secondary hypogonadism
reduced libido (sexual desire), secondary amenorrhoea, erectile dysfunction
what is the name of the condition where there is deficient ACTH due to panhypopituitarism
secondary hypoadrenalism
clinical presentation of secondary hypoadrenalism
fatigue (similar to Addison’s disease which is primary hypoadrenalism)
what is the name of the condition where there is deficient TSH due to panhypopituitarism
secondary hypothyroidism
clinical presentation of secondary hypothyroidism
fatigue
what does Sheehan’s syndrome describe
post-partum hypopituitarism (most common cause is post-partum haemorrhage) secondary to hypotension
epidemiology of Sheehan’s syndrome
less common in developed countries
characteristic of Sheehan’s syndrome in pregnancy and what post-partum haemorrhage leads to
anterior pituitary naturally enlarges in pregnancy (lactotroph hyperplasia) to produce more lactin, so if large post-partum haemorrhage and large gland, not much blood will flow to it, leading to pituitary infarction
3 clinical presentations of Sheehan’s syndrome with reasons
lethargy, anorexia, weight loss (TSH/ACTH/GH deficiency), failure of lactation (prolactin deficiency), failure to resume menses post-delivery (not getting period back); posterior pituitary not usually affected
when is pituitary apoplexy often dramatically presented
when patient has pre-existing pituitary tumours (adenomas); may be first presentation of pituitary adenoma
what can precipitate pituitary apoplexy
anti-coagulants as bleeding into pituitary gland
2 clinical presentations of pituitary apoplexy
severe sudden onset headache (enlargement stretches dura), visual field defect (compressed optic chiasm - bitemporal hemianopia)
if cavernous sinus involved in pituitary apoplexy, what may it lead to
have many cranial nerves and internal carotid arteries, so can get diplopia (IV, VI) - double vision, ptosis (III) - drooping of upper eyelid
what is the usual cause of panhypopituitarism
pituitary tumour, as tumours compress pituitary cells against bone of sella turcica
is panhypopituitarism naturally associated with the aging process
no
