Pituitary Pathology - Martin- Hypo + rest

Question 1

what is hypopituitarism?

Answer 1

this is a decreased secretion of pituitary hormones due to disease of the hypothalamus or pituitary

Question 2

hypofunction of the anterior pituitary occurs when _ percent of parencyhma is lost

Answer 2

75%

Question 3

if there is posterior pituitary dysfunction _ can present and it is usually of hypothalamic origin

Answer 3

diabetes insipidus

Question 4

what are most common causes of hypopituarism involving destruction of the anterior pituitary

Answer 4

1. tumors/masses
2. traumatic brain injury and subarachnoid hemmorhage
3. surgery to the pituitary
4. pituitary apoplexy
5. ischemic necrosis of the pituitary/sheehan syndrome
6. rathke cleft cyst
7. empty sella syndrome
8. hypothalamic lesions
9. inflammatory lesions
10. genetic defects

Question 5

what is the presentation og pituitary apoplexy

Answer 5

abrupt onset of bad headache, diplopia, cardiovascular collapse, sudden death

Question 6

ischemic necrosis of the pituitary aka sheehan syndtome aka post partum necrosis can cause hypopituitarism, how?

Answer 6

in pregnancy the anterior pituitary grows 2X its orignial size with no addition of blood supply, this gives a relative hypoxia and can lead to infarctionof the anterior pituitary

it can also be caused by DIC, sickle cell, increased intracranial pressure, traumatic brain injury

Question 7

what is a rathnke cleft cyst in the pituitary? how does it cause hypopituitarism?

Answer 7

this is a cyst lined by ciliated cuboidal epithelium that can have fluid accumulation that can compress and compromise the normal pituitaty gland

Question 8

what is empty sella syndrome

Answer 8

anything that destroys all or part of the pituitary

Question 9

what is primary empty sella syndrome?

Answer 9

this is a defect in the diaphragma sella that allows arachnoid mater and csf to herniate into the sella expansing the sella and compressing the pituitary

Question 10

primary empty sella syndrome is common in? and symptoms

Answer 10

obese women with multiple pregnancies

visual field defects, hyperprolactinemia, hypopituartism (if loos of functioning pituitary is sufficent)

Question 11

what is secondary sella syndrome

Answer 11

a mass/adenoma that enlarges the sella and then it is removed or undergoes infarctio causing a loss of pituitary function

Question 12

how can hypothalamic lesions cause hypopituitarism

Answer 12

there is a def in releasing factors from the hypothalamus to the pituitary which can cause dimimished released of ADH from the posterior pituitary and cause diabetes insipidus (this is just an example)

Question 13

how can inflammatory disorders can hypopituitarism?

Answer 13

inlammatory disorders like sarcoidosis or tuberculosis can cause a def in anterior pit hormones or post pit hormones (diabetes insipidus)

Question 14

what genetic defect can cause hypopituitarism?

Answer 14

PIT1 mutations which lead to deficiences in GH, prolactin and TSH

Question 15

decreased gh leads to?

Answer 15

dwarfism and growth failure

Question 16

decreases LH and FSH can cause

Answer 16

amenorrhea, infertilitym decreased libido, impotence, body hair loss

Question 17

decreased TSH and ACTH cause?

Answer 17

hypothyroidism and hypoadrenalism

Question 18

prolactin def causes

Answer 18

post partum lactation failure

Question 19

melanotropin def causes

Answer 19

pallor

remmeber this is made from POMC precusor just like ACTH

Question 20

_ is the term used to describe def in all pituitary hormones

_ hypopituitarism is more common. In general the secretion of _ is more likely to be affected

Answer 20

panhypopituitarism

GH/growth hormone

Question 21

the signs and symptoms of anterior pituitary insufficeince may occur _ (fast/slow/both)

Answer 21

slowly or suddenly (both)

Question 22

central diabetes inspiidus is?

Answer 22

a def of ADH from the posterior pituitary

Question 23

genetic cause of central diabetes insipidus

other causes of central diabetes insipidus

symptoms

Answer 23

AVP AD mutation
AVPR2 X linked mutation

head trauma, tumors, inflammatory disorders of the hypothalamus

polyuria *** increased serum sodium and osmolality—> dehdraytion—–> polydipsia

large volumes of dilute urine (less salty, salt is staying in the blood)

usually dehydration can be combated with increased water intake

Question 24

what is syndrome of inappropriate ADH (SIADH)

Answer 24

increased ADH leads to over resportion of free water and this leads to hyponatremia (low salt in the blood because water is diluting it)

Question 25

what causes SIADH

Answer 25

ectopic ADH from small cell carcinomas of the lungs, drugs , infections, trauma

Question 26

symptoms of SIADH

Answer 26

hyponatremia, cerebral edema, neurologic dysfunction, increased TBW, normal blood volume

no peripheral edema

Question 27

if you adminster DDVAP in central diabetes insipidus what happens

Answer 27

the kidney will respond with increased water retention and increase urine sodium/osmolality

Question 28

urine output in DI vs . SIADH

serum NA in DI vs SIADH

Urine Na in Di vs SIADH

Serum OSM in DI vs SIADH

Urine OSM in DI vs SIADH

Volume status in DI ws SIADH

Answer 28

urine output in DI vs . SIADH- high for DI

serum NA in DI vs SIADH- High for DI

Urine Na in Di vs SIADH- low for DI

Serum OSM in DI vs SIADH- high for DI

Urine OSM in DI vs SIADH- low for DI

Volume status in DI ws SIADH- low for DI

DI and SIADH are opposite values

Question 29

SIADH direct effect on ADH on the brain results in inapproporiate. _

Answer 29

thirst

Question 30

hypothalamic suprasellar tumors can cause _ or _ in the anterior pituitary or posterior pituitary or a combination of both

Answer 30

hypofunction or hyperfunction

Question 31

what are the types of hypothalamic suprasellar tumors?

Answer 31

glioma and craniopharyngioma

Question 32

what is a craniophryngioma?

Answer 32

a vestigial remnant of rathke pouch that is a slow growing intracranial tumors with a bimodal peak at ages 5-15 and over 65 years old

Question 33

symptoms of craniopharyngioma

Answer 33

headache, visual disturbances, groth restriction in kids

Question 34

apperacne of a craniopharyngioma

Answer 34

3-4 cm, solid or cystic, or multioculated, encapsulated

Question 35

craniopharyngiomas can enroach on the _ and bulge into the _ and _ of the brain

Answer 35

optic chiasm

floor of the 3rd venrticle

and base of the brain

Question 36

what are the two types of craniopharyngiomas?

Answer 36

adamantinomatous and papillary

Question 37

an adamantinomatous craniopharyngioma is most often seen in _ and _ are seen on radiographs. There is a mutation in _

Answer 37

kids

calcifications

CTNNB1 (b carenin)–> activation of the Wnt signaling pathway

Question 38

how does an adamanitnomatous craniopharyngioma look

Answer 38

nets and cords of stratified epithelium embedded in a spongy reticulum

palisading of equamous epithelium

compact wet keratin

calcifications

machine oil cholesteral rich deposits

fingerlets into the epithelium adjacent to the brain giving a brisk flial rxn

cholesterol crystals

Question 39

malignant transformation of craniopharygiomas into squamous carcinomas is rare but usually occurs after _

Answer 39

radiation

Question 40

papillary craniophayngiomas are seen in _ and have solid sheets and _ lined by squamous epithelium. They lack _, _, _, and _.

there is a _ mutation

Answer 40

adults

lack lamella keratin, calclifications, cysts, peripheral palisading

BRAF mutations at codon 600