Pituitary Gland (path) Flashcards
Makeup of posterior pituitary
neuroendocrine
makeup of anterior pituitary
vascular glandular
color of anterior pituitary
red
overall function of pituitary
role in regulation of most other endocrine glands
Connection of hypothalamus to posterior pituitary
neuroendocrine direct stimulation by neurons
connection of hypothalamus to anterior pituitary
vascular/endocrine through hypothalamic-hypophysial portal vessels
GRH stimulates & where
ACTH secretion, anterior pituitary
GnRH stimulates & where
LH/FSH secrection, anterior pituitary
GHRC stimulates & where
GH secretion, anterior pituitary
TRH stimulates & where
TSH and PRL secretion, anterior pituitary
SRIF stimulates & where
inhibition of GH, anterior pituitary
VIP stimulates & where
stimulation of PRL secretion, anterior pituitary
Dopamine stimulates & where
inhibition of PRL secretion , anterior pituitary
most cells in pituitary make what
GH (40-50%)
% of cells that make PRL
15-25%
arrangement of cells in anterior pituitary
vascular
arrangement in clusters (hard to see)
basophilic & acidophilic cells (hard to see)
adenohypophysis
anterior pituitary
neurohypophysis
posterior pituitary
hypopituitarism common causes (8)
postsurgical postirradiation cysts tumors ischemia/hemorrhage inflammation empty sella syndrome gene defect
Infarct usual location
usually anterior lobe
% of lobe that must be lost in infarct before symptomatic
75%
causes of infarct (6)
DM CVA ^ICP hypoperfusion (trauma, etc) sheehan's syndrome pituitary apoplexy
sheehan’s syndrome
post-partum necrosis/infarct of pituitary
from edema & blood loss
no prolactin –> lack of lactation. Take’s a minute to be symptomatic when not nursing
ddx for granulomatous histology of pituitary (4)
TB, fungal, sarcoid, idiopathic giant cell
hyperpituitarism (4 causes)
hyperplasia
pituitary adenoma
ectopic secretion by nonpituitary tumor
hypothalamic disorder
pituitary hyperplasia
common?
2 types
2 patterns
example
uncommon
primary & secondary
nodular & diffuse
ACTH hyperplasia in Addison’s disease
Pituitary adenoma - common?
very - 10% of intracranial neoplasms
pituitary adenoma
ages
associated condition
usually found earlier when functional or nonfunctional?
30-50 yo
MEN
functional
pituitary carcinoma - freq?
vanishingly rare
common symptom of pituitary enlargement
optic defects - chasm is very close
most common type of pituitary adenoma
prolactin cell adenoma (disproportionately high at 20-30%)
sex pref for pituitary adenoma
equal M/F
gross morphology of pituitary adenomas
fragemented (resection artifact)
well circumscribed
macro or micro (1cm division)
larger lesions may extend to suprasellar region
histopathlogy of pituitary adenomas
sheet-like
monomorphic
loss of reticulin fiber network
fx status not predicted from std histo appearance
immunohistochemical staining confirmatory
can fx status be predicted from std histo appearance in pituitary adenoma?
no. need immunohistochemical stains
diabetes insipidus
ADH deficiency –> excretion of large V dilute urine. hypernatremia, increased osM.
after trauma, tumors, inflammatory disorder, postsurg
SIADH
ADH excess –> ectopic secretion of tumor (small cell lung cancer, often). hyponatremia, cerebral edema, neuro dysfunction.
