Pituitary Disease Flashcards
hypothalamus is controlled by
controlled by cortical centers in brain and responds to emotions and sensory inputs
pituitary location
laterally and superiorly
laterally: cavernous sinuses
superiorly: optic chiasm
optic chiasm
crossing of the optic nerves
superior to pituitary
pituitary tumors lead to loss of peripheral vision
anterior pituitary hormones list (7)
TSH ACTH FSH LH GH PRL Endorphins
hypothalamus/pituitary
anterior communication
hypothalamus and transported to anterior lobe by pituitary portal circulation
posterior pituitary hormones list (2)
oxytocin
vasopressin (ADH_
posterior pituitary/hypothalamus communication
transported directly by neural network to the stalk and posterior lobe
products of hypothalamus
CRH GnRH GHRH Somatostatin TRH Dopamine
hypothalamus function
affects appetite, sleep, activity of autonomic NS and pituitary hormone secretions
hormones cause growth + release of hormones
HPA/Pituitary/Target:
Thyroid
TRH -> TSH -> T3/T4
thyroid gland
HPA/Pituitary/Target:
growth axis
GHRH -> GH -> IGLF-1
Liver
HPA/Pituitary/Target:
adrenal
CRH -> ACTH -> cortisol
HPA/Pituitary/Target:
gonadal
GnRH -> LH/FSH -> Testosterone/Progesterone, Estradiol/Inhibin
ovary, testes
functioning pituitary tumors
produce hormones
GH and prolactin
pituitary tumor effects depends on
- amount and kind of hormones produced
- location and size of tumor
- age/gender of patient
microadenomas
pituitary gland tumor
<10 mm
non cancer
prolactin producing
macroadenomas
pituitary gland tumor
> 10mm
growth hormone producing
carniopharyngioma
benign tumor arising from squamous cell nests
pediatric intracranial neoplasm
meningioma
typically benign and non functional pituitary gland
how do you screen for pituitary adenomas
screens for functionality by obtaining serum levels of prolactin, GH, TSH, ACTH, LH, FSH
symptoms of prolactinomas in women
menstrual irregularities or amenorrhea
vaginal dryness, pain with intercourse, and osteoporosis, galactorrhea
LH/FSH suppression and increased prolactin
symptoms of prolactinomas in men
typically present with macroadenoma and compression
decreased libido, erectile dysfunction, infertility
DDX of prolactinemia
drugs that inhibit dopamine
pregnancy***
ESRD/cirrhosis
endocrine disorder
pituitary or hypothalamic pathology
prolactinoma workup
prolactin level, TSH, and pregnancy test
MRI with contrast, thin cuts
prolactinoma treatment
yearly MRI + observation
can be treated with dopamine agonists(bromocriptine, stimulate DA r., surpasses prolactin and shrinks)
transsphenoidal pituitary adenomactomy
macroadenomas (children v. adults)
secrete growth hormone
child- epiphyses (growth plates) open and susceptible to GH, gigantism
adult - epiphyses are closed, bones larger not longer, acromegaly
GH normal function
secreted by somatotropin in anterior pituitary
pulsatile fashion
induces ILGF-1 secretion in liver
regulate muscle and bone growth + gluconeogenesis
GH secretion inhibited by
somatostatin and ILGF-1, hyperglycemia, leptin, multiple other peptides
GH secretion stimulated by
hypoglycemia
fasting or starvation
ghrelin
GH excess (macroadenomas)
acromegaly or gigantism
typically due to functional pituitary adenoma
gigantism
GH excess in children
dramatic linear growth acceleration
rare disorder
acromegaly
insidious onset
excess of GH + IGLF-1 causes insulin resistance
but NOT change in height
clinical manifestations of acromegaly
headache, visual loss
soft tissue overgrowth/skin thickening
coarsening of facial features and macroglossia
macroganthia
deepening of voice
spade hands
parasthesia/carpal tunnel
hyperhydrosis
enlargement soft tissue of tongue, larynx, pharynx
visceral enlargement
complications of acromegaly
increased CV disease
obstructive sleep apnea
diabetes mellitus
increased colon cancer
diagnosis GH macrodaenomas
random serum IGF-1
GOLD STANDARD: GH suppression test (if levels fall below 1 -normal)
thin slice MRI of pituitary
macro adenoma treatment
transphenoidal microsurgery
can do pharmacological (octreotide- somatostatin analog)
hypopituitarism
destruction of pituitary gland
rare, presents subtly
can have some or all hormone axises
symptoms, treatment depend on axis affected
hypopituitarism etiologies
- ischemia/infarction (Sheehan’s syndrome/preg.)
- tumor
- infiltrating disease
- infectious disease
- iatrogenic
hypopituitarism symptoms
GH loss
hypoglycemia
hypopituitarism symptoms
LH/FSH
failure of puberty
female- amenorrhea, loss of pubic/axillary hair, breast atrophy
male - erectile disfunction, decreased muscle mass, libido
hypopituitarism symptoms
TSH
hypothyroidism (cold intolerance, weight gain, myesdema, fatigue)
hypopituitarism symptoms
ACTH
adrenal insufficiency
shock
hypopituitarism treatment
ACTH
glugorigoid replacement only
hydrocortisone
hypopituitarism treatment
TSH
administer thyroid replacement
hypopituitarism treatment
LH/FSH
determine if fertility is desired
men treated with testosterone (no fertility) gonadotropins (fertility yes)
women HRT (no fertility) or gonadotropins (yes)
acondroplasia
short stature, genetics
gene coding for growth factor is mutated
short limbed dwarfism (proximal), brachydactyly
congenital GH deficiency
genetic mutation
patient falls off the chart by 6-12 months of age
diabetes insipidus
passage of large volumes of dilute urine
via central DI (decreased ADH secretion) or Nephrogenic (decreased ability to concentrate urine)
cardinal diabetes insipidus symptoms
polyuria, polydipsia, nocturia
polyuria
> 3 L of urine output daily
differential:
DM, DI, Primary polydipsia (psychiatric)
central DI etiologies
idiopathic
malignant or benign brain tumors
cranial surgery
head trauma
nephrogenic DI etiologies
Meds (LITHIUM)
renal disease
prganncy
hypokalemia/hyper kalemia
manifestations of diabetes insipidus
if free access to water, may be relatively asymptomatic
urine can be 3-20 L/day
normal physical exam
central DI treatment
due to DEFICIENCY of ADH secretion
DDAVP (synthetic ADH)
low salt diet and access to water
nephrogenic DI treatment
resistance of kidney to ADH
low solute diet
HCTZ +/- amiloride
why do i give someone with DI a diuretic?
decreases available water in collecting tubules (so hold onto water)
therefore proximal tubule senses less water, and takes up more water
pituitary metastases
very rare
present with mass effects
typically in posterior pituitary
often breast, GI, lung CA
