Endocrine pathology I Flashcards
pituitary adenoma
benign tumor of anterio pit cells. if the tumor produces hormones, it is functional. otherwise, it is non-function
how do nonfunctional tumors present?
mass effect: bitemproal hemianopsia- pressing on the optic chiasm. both eyes loose peripheral vision.
hypopituitarism: compresses normal pituitary. Sighns and symptoms of the hormones normally made by pit
headache
How do functional tumors of the pituitary present: prolactinoma?
prolactinoma- most common type. signs and symptoms: galactorrhea and amenorrhea in women (nhibits GNRH synthesis and release)
in males, you see decr. libido (no GNRH) and headache. males don’t get galactorrhea- not enough breast tissue becase no lobular units
what is the treatment of prolactinoma?
dopamine agonists- tumors shrink (bromocryptine0
surgery
What do you see in terms of presentation for grhowth hormone adenoma?
gigantism in kids
acromegaly in adults: excess growth of bones of hands, feet, and jaw. growth of visceral organs like heart- can cause cardiac failure. large tongue
often associated with secondary diabetes- GH decr. uptake of glucose into cells
how do you make dx of growth hormone adenoma
elevated GH and IGF-1
lack of suppression of GH release by glucose
tx of growth hormone adenoma
octreotide: somatostatin analog that blocks the response of anterior pituitary to GHRH
GH receptor antagonists (pegvisomant)
surgery
What is hypopituitarism
insufficient production of hormones of ant. pituitary
causes of hypopituitarism
pituitary adenoma in aduls- compresses normal pituitary
apoplexy- bleeding into adenoma causes rapid growth
craniopharyngeoma in kids
Sheehan syndrome: during preg, there is a high hornome demand. pit doubles in size- but blood flow doesn’t. susceptible to infarction if lots of blood loss happens during delivery. they present with poor lactation and loss of pubic hair.
empty sella syndrome: trauma, or congenital defect of the sella with herniation of the arachnoid into the sella- compresses normal pituitary
What 2 hormones are released by post pit? Where are they made? what do they do?
ADH and oxytocin. both made in hypothalamus and transmittted via axons.
ADH: regulates free water at distal tubules in collecting ducts
oxytocin: mediates uterine contractions and release of breast milk
Central diabetes insipidus: causes, what is it
ADH deficiency- you urinate too much.
may be d/t hypothalamic or post pit pathology
clinical features of diabetes insipidus
polyuria and polydipsia
hypernatremia and high serum osmolality
low urine osmolality and specific gravity
Dx of diabetes insipidus
water deprivation fails to incr. urine osmolality
Tx of diabetes insipidius
give ADH analog- desmopressin
what is nephrogenic diabetes insipidus?
inpaired renal response to ADH
d/t inherited mutsations or drugs (lithium)
similar to centrial DI but no response to desmopressin