Pituitary

Question 1

most common types of pituitary adenomas

Answer 1

1 - prolactinoma

2 - nonfunctional gonadotroph adenoma

Question 2

incidence of central DI in pituitary adenomas

Answer 2

essentially zero

Question 3

pituitary lesion with DI should raise concern for what

Answer 3

metastatic lesion
craniopharyngioma
hypophysitis
sarciodosis

Question 4

postpartum female with agalactia, fatigue

Answer 4

Sheehan syndrome

Question 5

T value below this should prompt MRI pituitary central hypogonadism

Answer 5

< 150 pg/dL

Question 6

typical order of pituitary hormone deficiency after cranial irradiation

Answer 6

GH
FSH/LH
ACTH
TSH

Question 7

cause of Sheehan syndrome

Answer 7

typically massive uterine hemorrhage/hypovolemia

Question 8

treatment of pituitary apoplexy

Answer 8

empiric hydrocortisone

neurosurgical consult

Question 9

cause of empty sella syndrome

Answer 9

intrasellar herniation of the suprasellar subarachnoid space with compression of the pituitary gland producing a remodeling of the sella

Question 10

cause of mild prolactin elevation in empty sella syndrome

Answer 10

stalk stretching

Question 11

functional causes of pituitary insufficiency

Answer 11

exogenous steroids
exogenous testosterone
hypothalamic amenorrhea due to exercise, anorexia
critical illness
opiates

Question 12

antiepileptics increase catabolism of which steroids?

Answer 12

dexamethasone/prednisone > hydrocortisone

Question 13

immunohistochemical staining for corticotroph tumors

Answer 13

T-Pit

Question 14

immunohistochemical staining for gonadotroph tumors

Answer 14

SF-1

Question 15

immunohistochemical staining for thyrotrophs, somatotrophs, and lactotroph tumors

Answer 15

Pit-1

Question 16

what is the significance of silent or plurihormonal pituitary tumors?

Answer 16

aggressive behavior
invasive
high rates of recurrence
can progress to functional tumors over time

Question 17

are pituitary tumors heritable

Answer 17

< 5% are heritable
MEN1, MEN4
FIPA
Succinate dehydrogenase mutations (SDH)

Question 18

conditions that can cause “pseudotumor” of the pituitary gland

Answer 18

severe hypothyroidism
puberty
pregnancy

Question 19

medical therapy for nonfunctional adenomas

Answer 19

cabergoline

Not FDA approved but some studies that show it may be beneficial

Question 20

rate of growth of pituitary adenomas

Answer 20

typically 1-2mm per year

Question 21

in what percentage of patients with pituitary insufficiency related to NFA will there be improvement or normalization of pituitary hormone function postoperatively?

Answer 21

15-30%

Question 22

how long after surgery to re-test pituitary function?

Answer 22

6-12 weeks

Question 23

equivalent doses of subq/IV, nasal, and oral desmopressin

Answer 23

1mcg
10mcg
100mcg

Question 24

most common sodium abnormality after pituitary surgery

Answer 24

SIADH

Question 25

management of postoperative DI

Answer 25

``` free water (by mouth if thirst mechanism intact) PRN desmopressin (usually transient) rarely permanent - if so, will need to go home on desmopressin ```

Question 26

nadir of SIADH post surgery

Answer 26

5-9 days

Question 27

fluid restriction instructions for post pituitary surgery patients on discharge

Answer 27

1-1.5L of fluids/day | sodium level in 7 days

Question 28

ddx of post TSS hyponatremia

Answer 28

SIADH hypothyroidism adrenal insufficiency

Question 29

typical pattern of pituitary hormone deficiency

Answer 29

``` GH FSH/LH TSH ACTH Prolactin ```

Question 30

how common are pituitary carcinomas

Answer 30

extremely rare. < 0.2% or pituitary carcinomas

Question 31

most common manifestation of pituitary metastatic disease

Answer 31

DI

Question 32

only pituitary hormone primarily regulated by negative feedback

Answer 32

prolactin (constant negative feedback via dopamine)

Question 33

effect of estrogen on prolactin level

Answer 33

increases

Question 34

physiologic states with elevated prolactin

Answer 34

pregnancy, lactation | stress, exercise, nipple stimulation

Question 35

how high can prolactin levels go in pregnancy

Answer 35

200-300 ng/mL

Question 36

definition of galactorrhea

Answer 36

discharge of milk from the breast not associated with pregnancy or lactation

Question 37

can cabergoline be used in pregnancy

Answer 37

probably safe, but stop if possible

Question 38

when to re-image macroprolactinoma after starting cabergoline

Answer 38

3 months

Question 39

how long for prolactin to normalize on dopamine agonist therapy?

Answer 39

weeks-months

Question 40

how long is medical therapy required for prolactinomas?

Answer 40

usually lifelong, but can try to stop as ~20% of patients will be cured

Question 41

rhinorrhea in a pt with macroprolactinoma after starting on cabergoline

Answer 41

CSF leak from rapid shrinkage

Question 42

indications for surgery on macroprolactinoma

Answer 42

intolerance to medical therapy unresponsive to medical therapy young female desiring pregnancy (to avoid medical therapy while pregnant)

Question 43

normal function of GH in children and adults

Answer 43

children - linear growth | adults - metabolic effects

Question 44

does GH directly affect peripheral tissues?

Answer 44

Very little. Most effects are mediated thru IGF-1.

Question 45

single biggest clue in examining a patient suspected of having acromegaly?

Answer 45

old photographs

Question 46

metabolic effects of acromegaly

Answer 46

``` HTN DM cardiomyopathy OSA 30% higher mortality rate ```

Question 47

which pituitary hormones are glycoproteins

Answer 47

FSH LH TSH

Question 48

Ddx for transient increase in serum T4 and normal/elevated TSH

Answer 48

Took Lt4 right before lab test (noncompliant) other meds (amiodarone, amphetamines, heparin, NSAIDS) Acute psychiatric illness Acute liver disease

Question 49

Ddx for patients with permanent increase in serum T4 and normal/elevated TSH

Answer 49

``` TSHoma thyroid hormone resistance HAMA antibodies (heterophile antibodies) FDH (familial dysalbuminemic hyperthyroidism) excessive TBG ```

Question 50

how to differentiate between TSHoma and resistance to thyroid hormone

Answer 50

elevated alpha subunit - TSHoma elevated SHBG - TSHoma T3 suppression test - TSHoma won't suppress

Question 51

treatment of choice for TSHoma

Answer 51

surgery

Question 52

medical therapies for TSHoma

Answer 52

octreotide | thionamides/bblockers preoperatively

Question 53

what can happen to the pituitary gland in longstanding hypothyroidsm

Answer 53

pseudotumor due to pituitary hyperplasia

Question 54

is thyroid hormone resistance typically de novo or hereditary

Answer 54

hereditary, autosomal dominant

Question 55

in functional pituitary gonadotropinomas, is the FSH or LH typically higher

Answer 55

FSH

Question 56

which pituitary hormones are commonly elevated in ESRD patients

Answer 56

prolactin (avg 65 ng/mL, range 48-195) | GH (increased peripheral tissue resistance)

Question 57

pt with panhypopit is started on GH. Free t4 concentration drops. Reason?

Answer 57

GH increased conversion from T4 to T3.

Question 58

effect of testosterone supplementation on TBG

Answer 58

decreased TBG (and subsequent increase in free t4)

Question 59

female with panhypopit on oral estradiol and GH who wants to change to transdermal estradiol. what to do with GH dose?

Answer 59

decrease by 50%. women on oral e2 require 2-3x dose of GH replacement, so changing to transdermal requires dose reduction

Question 60

female pt with hx of metastatic breast ca who presents with adrenal crisis and then gets hypotensive with brisk UOP after steroid replacement. Cause?

Answer 60

unmasking of central DI after starting on glucocorticoids