Disorders of Anterior Pituitary 1

Question 1

what is the most common pituitary tumor

Answer 1

• prolactinoma

Question 2

75% of the nonsecratory tumors involve which subunit

Answer 2

• alpha

Question 3

prolactin stimulates what process

Answer 3

• milk production by an estrogen primed mammary gland

Question 4

prolactin decreases levels of

Answer 4

• gonadotropins (LH and FSH) by inhibiting GnRH

- and estrogen

Question 5

estrogen (stimulates/inhibits) prolactin

Answer 5

• stimulates

Question 6

what hormone from the hypothalamus stimulates release of prolactin

Answer 6

• TRH (due to hypothyroidism)

- has no true release hormone though

Question 7

drugs that can cause hyperprolactinemia

Answer 7

• antihypertensives (verapamil)
• GI (metoclopramide, H2 blockers)
• antipsychotics
• antidepressants

Question 8

clinical manifestations of hyperprolactinemia in women

why

Answer 8

• galactorrhea (due to increased prolactin)
• amenorrhea (due to decrease of estrogen)
• infertility (loss of mid cycle surge of LH and FSH)
• osteoporosis (loss of protective estrogen effect)

Question 9

clinical manifestations of hyperprolactinemia in men

Answer 9

• impotence
• visual field abnormalities
• headache
• extraocular muscle weakness

Question 10

what is oligomenorrhea

how does hyperprolactinemia cause this

Answer 10

• infrequent menstruation
• progressive increase in prolactin results in defective LH and FSH secretion which results in lower estrogen (because FSH produces estrogen)

Question 11

tests to order when assessing for hyperprolactinemia

Answer 11

• prolactin
• FSH/LH
• TSH
• creatinine (rule out renal failure)
• pregnancy test

Question 12

history when assessing for hyperprolactinemia should focus on

Answer 12

• medication usage

Question 13

in hyperprolactinemia, assess visual fields when MRI shows

Answer 13

• optic chiasm compression

Question 14

how does craniopharyngioma cause hyperprolactinemia

Answer 14

• inhibit dopamine release from hypothalamus `

Question 15

treatment for pathological hyperprolactinemia

Answer 15

• dopamine agonist therapy

- surgery and radiotherapy have limited use

Question 16

what dopamine agonists do we give for treatment of hyperprolactinemia

Answer 16

• cabergoline

- bromocriptine

Question 17

side effects of dopamine agonist therapy

Answer 17

• nausea/vomiting

- orthostatic hypotension

Question 18

Acromegaly is due to

Answer 18

• excessive growth hormone secretion

- generally due to pituitary adenoma

Question 19

pathologic changes due to acromegaly

Answer 19

• acral (peripheral body parts) changes (prominent chin and increased hand size)
• sweating
• thickening of skin
• hypertension
• neoplasia
• cardiomyopathy

Question 20

how do we diagnose acromegaly

Answer 20

• measure IGF-1 levels (will be high since GH stimulates release of IGF-1) - FIRST LINE
• measure GH levels after glucose administration (normally should decrease as GH decreases after glucose admin. in patients with acromegaly, it will remain a high level)

Question 21

growth hormone is most commonly released at what point during the day

Answer 21

• at night during sleep

Question 22

acromegaly with what condition has the lowest survival

Answer 22

• cardiac disease

Question 23

goals of acromegaly treatment

Answer 23

• return life expectancy to normal

- restore normal levels of GH and IGF-1

Question 24

treatment for acromegaly

Answer 24

• surgery (transsphenoidal hypophysectomy) FIRST LINE
• radiotherapy - delayed response of tumor and you destroy the pituitary
• medical therapy

Question 25

medical therapy for acromegaly

AND WHAT DRUG IS THIS

which is first line

Answer 25

• somatostatin analog - OCTREOTIDE
• dopamine agonist (binds to D2 receptors on anterior pituitary which blocks release of GH. tumor will have increased number of D2 receptors) - BROMOCRIPTINE/CABERGOLINE
• GH receptor antagonist - PEGVISOMANT (first line)