Pathology of the Pituitary Flashcards
location of pituitary
sella turcica
80% of pituitary
adenohypophysis
ADH and oxytocin production
neurohypophysis of pituitary gland
secreted by anterior pituitary
TSH PRL ACTH GH FSH LH
control of GH release
somatostatin - inhibitory
GHRH - stimulatory
cells of anterior pituitary
somatotrophs mammosomatotrophs lactotrophs corticotrophs thyrotrophs gonadotrophs
cells secreting GH
somatotrophs
cells secreting GH and PRL
mammosomatotrophs
cells secreting PRL
lactotrophs
cells secreting ACTH, POMC, and MSH
corticotrophs
cells secreting TSH
thyrotrophs
cells secreting FSH and LH
gonadotrophs
vasopressin
ADH
from posterior pituitary
ACTH and POMC
same analog
hypopituitary - loss of pigmentation
acidophil
cells of pituitary
loss of lateral visual fields
bitemporal hemianopsia
local mass effect with pituitary gland size increase
N/V, headaches, papilledema
cerebral edema
pituitary growth leading to brain swelling
milky discharge
galactorrhea
bilateral galactorrhea, onset of HAs, elevated PRL
pituitary adenoma - prolactinoma
combined features of GH and PRL excess
mammosomatotroph pituitary adenoma
types of pituitary adenomas
lactotroph - most common somatotroph mammosomatotroph corticotroph thyrotroph gonadotroph
gigantism and acromegaly
somatotroph pituitary adenoma
HRAS
pituitary carcinoma
GNAS
GH adenomas
PRKAR1A
GH and PRL adenomas
MEN1
GH, PRL, ACTH adenomas
larger pituitary adenomas
tend to be nonfunctional - more local mass effects
bleeding into pituitary adenoma
pituitary apoplexy
amenorrhea, galactorrhea, loss of libido, infertility
prolictinemia
typically female age 20-40
1/4 amenorrhea cases
lactotroph adenoma
men and older women with lactotroph adenoma
hormone manifestations may be subtle
-so not detected until large size - macroadenoma
dense core granules
think endocrine source
gigantism
children - before epiphyseal plates close
acromegaly
adults - after epiphyseal plates close
IGF-1
from liver
-stimulated by GH
causes many of the clinical manifestations of somatotroph adenomas (acromegaly and gigantism)
acromegaly growth
skin, soft tissue, thyroid, heart, liver, adrenal, bones of face, hands, and feet
increased body size with long arms and legs
gigantism
increased bone density
hyperostosis
seen in somatotroph adenomas
protrusion of jaw
prognathism
seen in somatotroph adenoma
sausage hands
acromegaly
GH excess associations
gonadal dysfunction DM muscle weakness HTN arthritis CHF GI cancer risk increase
diagnosis of GH excess
elevated serum and IGF-1
sensitive test for acromegaly
failure to suppress GH production in response to oral load of glucose**
cushings disease vs. syndrome
syndrome - elevated cortisol
disease - elevated cortisol due to corticotroph adenoma in pituitary
predominant hormone in gonadotroph adenoma
FSH
hyperthyroidism
can be due to thyrotroph adenoma
rare**
nonfunctioning pituitary adenomas
25-30% of all pituitary tumors
aka silent variant or null-cell adenomas
typically present with mass effects
can lead to hypopituitarism
middle aged men and women, impaired vision, HA, diplopia, pituitary apoplexy
gonadotroph adenoma mass effects
also impaired secretion of LH - decrased energy and libido in men and amenorrhea in premenopausal women
most common cause of hyperpituitarism
anterior lobe pituitary adenoma
macroadenoma
greater than 1cm in diameter
corticotroph adenoma
secrete ACTH
- cushing syndrome
- hyperpigmentation
25yo M IED explosion with multiple medical problems, hypopigmentation, loss of libido, impotence, loss of pubic and axillary hair
FSH and LH decrease
TSH increase
ACTH decreased
hypothyroid
wound to neck - loss of thyroid
most common causes of pituitary hypofuction
traumatic brain injury
subarachnoid hemorrhage
rathke cleft cyst
differential for hypopituitarism
pituitary growth failure
in children
hypopituitary
amenorrhea and infertility
gonadotropin deficiency
MSH
synthesized in anterior pituitary
hypopituitarism - can lead to pallor due do loss of MSH stimulation on melanocytes
ADH deficiency
diabetes insipidus
with polyuria
ADH excess
SIADH
-hyponatremia - because of excess free water absorption
52yo male smoker, confusion, HA, hyponatremia
small cell carcinoma of lung
SIADH
23yo M head trauma in MVA, confused
hypernatremia
subdural hematoma
possible diabetes insipidus
loss of ADH from pituitary
diagnosis of diabetes insipidus
neurogenic (central) and nephrogenic
large volume dilute urine, lower specific gravity, hypernatremia, hyperosmolar, thirst, polydipsia
diabetes insipidus
craniopharyngioma
compact lamellar wet keratin and cords of squamous epitheilum
3-4cm
children - adamantinomatous
adult - papillary
motor oil like with tumor aspiration
adamantinomatous craniopharyngiomas
also see calcification
prognosis of craniopharyngiomas
less than 5cm excellent
-recurrent free
larger lesions - mre invasive
malignant transformation is rare
