Pituitary Pathology Flashcards
what is the anterior pituitary also known as
adenohypophysis
what is the anterior pituitary derived from
rathke’s pouch
what hormones does the anterior pituitary secrete
trophic: TSH, ACTH, FSH, LH
non-trophic: GH and Prolactin
what is the posterior pituitary also known as
neurohypophysis
what does the pituitary consist of
extension of neural tissue consists of modified glial cells and axonal processes
what hormones does the posterior pituitary secrete
ADH (vasopressin) and oxytocin
where are posterior pituitary hormones produced
hypothalamus
how are the cells in the pituitary arranged
in islands like other endocrine glands or arranged in clusters
are pituitary adenomas benign or malignant
benign
what cells are pituitary adenomas derived from
anterior pituitary cells
how common are pituitary adenomas
relatively common (10% intra-cranial tumours)
what syndrome is associated with pituitary adenomas
MEN1 (Wermer Syndrome)
pituitary adenomas are quite characteristic
what is significant about macro-adenomas (over 1cm)
can cause symptoms due to compression
how are pituitary adenomas classified
by the cell type/hormone produced
which is the most common pituitary adenoma
prolactinoma (30%)
what can be some symptoms of large adenomas and why
visual field defects (press on optic chiasma-bitemporal hemianopia), can cause pressure atrophy of surrounding normal tissue, infarction can. lead to panhypopituitarism
what is panhypopituitarism
lose all anterior pituitary, ischaemic necrosis along with tumour
what are some symptoms of a prolactinoma
infertility, lack of labido, amenorrhea (25%)
what is the second most common pituitary adenoma
growth hormone secreting
what can GH cause
increase in Insulin Like Growth Factor (IGF)
what happens in growth hormone pituitary adenoma
stimulation of growth of bone, cartilage and connective tissue
what are some symptoms of growth hormone pituitary adenoma
giantism or acromegaly
what does ACTH secreting pituitary adenomas cause
cushings, bilateral adrenocortical hyperplasia
how common are pituitary carcinomas
rare (less than 1%)
