20 Pituitary Flashcards
Hypothalamus releases:
TRH, CRH, GnRH, GHRH, dopamine
Released into the median eminence
Passes through neurohypophylsis on way to adenohypophysis
Dopamine
Inhibits prolactin secretion
Posterior pituitary
Neurohypophysis
ADH, oxytocin
Does not contain cell bodies
ADH
Supraoptic nuclei
Regulated by osmolar receptors in hypothalamus
Oxytocin
Paraventricular nuclei in hypothalamus
Anterior pituitary
Adenohypophysis
Releases ACTH, TSH, GH, LH, FSH and prolactin
Does not have its own direct blood supply - passes through neurohypophysis (portal venous sustem)
Bi-temporal hemianopia
Pituitary mass compressing optic nerve at chiasm
Non-functional tumors
Macroadenoma
Mass effects and decreased ACTH, TSH, GH, LH, FSH
Tx: Transsphenoidal resection
Contraindications to transsphenoidal approaches
Suprasellar extension
Massive lateral extension
Dumbbell-shaped tumor
Medical treatment for pituitary tumors?
Bromocriptine (dopamine agonist)
Prolactinoma
Microadenoma
Requires >150 for symptoms
Sx: galactorrhea, irregular menses, decreased libido, infertility
Tx: bromocriptine, cabergoline, surgery for failure of medical managment
What is the most common pituitary adenoma?
Prolactinoma
Prolactinoma in pregnancy - medical treatment?
Bromocriptine
When do you resect macro prolactinoma?
Hemorrhage
Visual loss
Wants pregnancy
CSF leak
Acromegaly
Excess GH
Sx: HTN, DM, gigantism, cardiac symptoms
Dx: elevated IGF-1, GH >10
Tx: Octreotide or transshenoidal resection XRT and bromocriptine
Sheehan’s syndrome
Post-partum trouble lactating
Sx: amenhorrhea, adrenal insufficiency, hypothyroidism
Due to intrapartum pituitary ischemia
Tx: hormone replacement
Craniopharyngioma
Benign calcified cyst, remnants of rathke’s ouch, grows along pituitary stalk to suprasellar location
Sx: endocrine abnormalities, visual disturbances, HA, hydrocephalus
Tx: Surgical resection
Post-op complication of craniopharyngioma resection?
Diabetes insipidus
Bilateral pituitary masses - workup?
Check pituitary axis hormones.
If okay - probably mets
Syndrome that occurs after bilateral adrenalectomy?
Nelson’s syndrome
Increased CRH cause pituitary enlargement - amenhorrhea and bi-temporal hemianopia
Also increased B-MSH - hyperpigmentation
Tx: Steroids
Adrenal insufficiency secondary to hemorrhage?
Waterhouse-Frederichsen syndrome
Associated with meningococcal sepsis
