Roveda- pathology of pituitary Flashcards
sits in sella turcica that is posterior from sphenoid sinus
pituitary gland
normal size of pituitary gland
1 cm
L
R
L: posterior pituitary
R: anterior pituitary
anterior pituitary is derived from ____
oral surface ectoderm
posterior pituitary is derived from _____
neuroectoderm
hormones of the anterior pituitary are produced where
anterior pituitary
hormones of posterior pituitary are produced where
hypothalamus
anterior pituitary cells
acidophils from anterior pituitary
somatotropes (GH)
lactotropes (PRL)
basophils of anterior pituitary
corticotropes (ACTH)
gonadotropes (FSH, LH)
thyrotropes (TSH)
posterior pituitary
Excess hormones
Usually limited to 1 anterior hormone
hyperpituitarism
Deficiency hormones
Usually involves all anterior hormones
hypopituitarism
Bitemporal hemianopsia due to compression of the optic chiasm (if they have an enlargement of pituitary gland)
tunnel vision (peripheral vision messed up)
sx’s of elevated intracranial pressure due to pituitary disease
N/V, HA
manifestation of pituitary disease with sudden hemorrhage and necrosis into pituitary gland—-acute onset of sx’s
pituitary apoplexy
main 2 causes of hyperpituitarism
pituitary adenoma
ectopic hormone production by extra pituitary tumors
can be functional or silent
invasive/non-invasive
micro or macro
pituitary adenomas
size of microadenoma
<1 cm
size of macroadenoma
> 1 cm
to diagnose pituitary adenoma
IHC stain
labs
radiography
L
R
L: pituitary adenoma
R: bone marrow b/t bone spicules
monotonous population of cytologically uniform cells
pituitary adenoma
pituitary ___adenoma compressing optic chiasm
macroadenoma
pituitary microadenoma
pituitary adenomas
4 most common pituitary adenomas
prolactin cell adenoma
GH cell adenoma
ACTH cell adenoma
mixed GH-PRL adenoma
pituitary adenoma
Excess hormone
Hypopituitarism (non-functioning adenomas)(if the adenoma is compressing normal pituitary tissue)
Mass effect resulting in visual field defects
pituitary adenoma
most common functioning pituitary tumor
prolactinomas
elevated ____ causes amenorrhea and galactorrhea, loss of libido and infertility in women
increased PRL
elevated _____causes impotence and gynecomastia in males
PRL
elevated _____-levels inhibit secretion of GnRH which leads to decreased FSH and LH, which leads to decreased progesterone, estrogen and testosterone which leads to amenorrhea and loss of libido
PRL
pregnancy
lactation
hypothyroidism
renal failure
interference with dopamine inhibition
other causes of elevated prolactin
in hypothyroidism, elevated ____ upregulates prolactin
TRH
can cause what
elevated prolactin
treatment for prolactinoma
transphenoidal surgery
dopamine receptor agonists
increase in _____ increases IGF-1
these act in conjunction to cause overgrowth of bones and muscle
GH
can cause gigantism in children before epiphyses closure
GH adenoma
can cause acromegaly in adults (after epiphyses closure)
also can be due to brain injury
GH adenoma
____ and ____ can cause visceral growth and bone growth
acromegaly and gigantism
hyperostosis spine
prognathism (protrusion of jaw)
cardiomyopathy
acromegaly and gigantism
to diagnose GH adenoma
elevated serum IGF-1
Imaging
to treat GH adenoma
transphenoidal surgery
Octreotide
Leads to adrenal hypersecretion of cortisol resulting in Cushing disease / syndrome
ACTH cell adenoma
pituitary adenoma is producing ACTH and acting on adrenal glands and increase in cortisol which results in cushings syndrome
Cushing disease
cushing ___ can be caused by other factors not just pituitary adenoma
syndrome
___ and ___ are formed from the cleavage of POMC (proopiomelanocortin)
ACTH and MSH
patients with ____ often have hyperpigmented skin
Cushing syndrome
Truncal obesity and thin extremities and buffalo hump; abdominal striae
Cushing disease/syndrome
Cushing syndrome
other adenomas may come to clinical attention due to mass effect and/or ______ (compression of normal pituitary tissue)
hypopituitarism
decrease secretion of anterior pituitary hormones
hypopituitarism
associated w/ posterior pituitary deficiencies
hypopituitarism originating in hypothalamus
tumors/lesions
brain injury
surgery
pituitary apoplexy
sheehan syndrome
empty sella syndrome
can all cause hypopituitarism
postpartum hemorrhage resulting in hypovolemic shock and ischemic necrosis of the pituitary
Sheehan syndrome
____ can grow so large it can compress normal functioning pituitary tissue
tumors/lesions
(defect in sella turcica); arachnoid tissue going into where pituitary sits and compression
empty sella syndrome
treat pituitary deficiencies
surgery
or
replace target gland hormone
most life threatening pituitary deficiency is ______
ACTH deficiency
pituitary apoplexy
red and dead
pituitary apoplexy
postpartum necrosis of anterior pituitary gland
usually associated w/ obstetric hemorrhage/shock
Sheehan syndrome
failure to lactate, CV collapse, hypothyroidism
Sheehan syndrome
enlarged and empty sella turcica
CSF and arachnoid can herniate into sella
empty sella syndrome
2 main posterior pituitary syndromes
diabetes insipidus
SIADH
promotes uterine contraction
stimulates myoepithelial cells breast-milk letdown
released in response to suckling and cervix dilation
oxytocin
Released in response to increased plasma osmotic pressure, left atrial distention, exercise and certain emotional states.
Results in water resorption in the collecting tubules of the kidney
ADH (vasopressin)
due to ineffective ADH axis
inappropriately dilute urine
diabetes insipidus
Excessive urination (polyuria) due to an inability of the kidney to resorb water properly from the urine
Diabetes insipidus
increase water intake
psychiatric patients
(differential for diabetes insipidus)
primary polydipsia
functions to concentrate urine and conserve water
ADH
Absence/insufficient ADH
Central Diabetes Insipidus
Renal resistance to ADH
Normal ADH secretion (kidney just unresponsive to ADH)
Nephrogenic Diabetes Insipidus
excessive urination and thirst
low urine osmolality
increased serum osmolality
hypernatremia
Diabetes Insipidus
in _____DI, kidneys are functioning so they will have increase in urine osmolality when given ADH injection
central DI
in ____DI, kidneys wont respond to ADH
nephrogenic DI
to treat central DI
Desmopressin (ADH analog)
to treat nephrogenic DI
thiazides (look this up)
indomethacin (also treats PDA)
Excess ADH
Results in resorption of excessive amounts of free water
SIADH
hyponatremia (Acute onset: cerebral edema leading to lethargy, weakness, seizures, coma, etc)
SIADH
SCLC
TB, pneumonia
head trauma
drugs
causes of SIADH
decreased serum Na+ and Posm
increase Uosm
plasma Cr normal
SIADH
to treat SIADH
fluid restriction
V2 receptor antagonists
treat cause
