Chapter 20: Pituitary Flashcards Preview

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Flashcards in Chapter 20: Pituitary Deck (35):
1

Releases TRH, CRH, GnRH, GHRH, and dopamine into median eminence; passes through neurohypophysis on way to adenohypophysis

Hypothalamus

2

Inhibits prolactin secretion

Dopamine

3

Neurohypophysis

Posterior pituitary

4

Supraoptic nuclei, regulated by osmolar receptors in hypothalamus

ADH

5

Paraventricular nuclei in hypothalamus

Oxytocin

6

Does not contain cell bodies

Neurohypophysis

7

80% of pituitary gland

Anterior pituitary (adenohypophysis)

8

What does the anterior pituitary release?

ADH, TSH, GH, LH, FSH, PROLACTIN

9

Blood supply of anterior pituitary

Does not have its own direct blood supply; passes through neurohypophysis 1st (portal venous system)

10

Pituitary mass compressing optic nerve (CNII) at chiasm

Bi-temporal hemianopia

11

Almost always macro adenomas; present with mass effect and decreased ACTH, TSH, GH, LH, FSH. Tx: transsphenoidal resection

Nonfunctional tumors

12

Tx: nonfunctional pituitary tumors

Transsphenoidal resection

13

Contraindications to transsphenoidal approaches

Suprasellar extension, massive lateral extension, dumbbell-shaped tumor

14

Most pituitary tumors respond to...

Bromocriptine (dopamine agonist)

15

- MC pituitary adenoma
- Mostly microadenomas

Prolactinoma

16

Tx: prolactinoma

- Most patients do not need surgery

17

When do symptoms occur with prolactinoma?

Prolactin is usually > 150 for symptoms to occur

18

Galactorrhea, irregular menses, decreased libido, infertility

Prolactinoma

19

Tx: prolactinoma

Bromocriptine (safe in pregnancy) or cabergoline (both are dopamine agonists) for most or transsphenoidal resection for failure of medical management

20

When do you resect macroadenomas in prolactinoma?

Resection with hemorrhage, visual loss, wants pregnancy, CSF leak

21

HTN, DM, gigantism; can be life-threatening secondary to cardiac symptoms (valve dysfunction, cardiomyopathy)
- Usually macroadenomas

Acromegaly (growth hormone)

22

Dx: Acromegaly

Elevated IGF-1 (best test), growth hormone > 10 in 90%

23

Tx: acromegaly

Octreotide or transphenoidal resection; XRT and bromocriptine can be used as secondary therapies

24

- Post partum trouble lactating (usually 1st sign)
- Can also have amenorrhea, adrenal insufficiency, and hypothyroidism

Sheehan's syndrome

25

What causes Sheehan's syndrome?

Due to pituitary ischemia following hemorrhage and hypotensive episode during childbirth

26

Tx: Sheehan's syndrome

Hormone replacement

27

Benign calcified cyst, remnants of Rathke's pouch; grows along pituitary stalk to suprasellar location

Craniopharyngioma

28

Most frequently presents with endocrine abnormalities, visual disturbances, headache, hypocephalus

Craniopharyngioma

29

Tx: craniopharyngioma

Surgery to resect cyst

30

Frequent complication s/p craniopharyngioma

Diabetes insipidus

31

What to look for in bilateral pituitary masses?

Check pituitary axis hormones; if OK, probably metastases

32

- Occurs after bilateral adrenalectomy resulting in amenorrhea and visual problems (bi temporal hemianopia)
- Hyperpigmentation

Nelson's syndrome

Tx: steroids

33

Why amenorrhea and visual problems in Nelson's syndrome?

Bilateral adrenalectomy -> increased CRH causes pituitary enlargement resulting in amenorrhea and visual problems (bitemporal hemianopia)

34

Why hyperpgimentation in Nelson's syndrome?

Bilateral adrenelecotmy -> beta-MSH, a peptide byproduct of ACTH

35

Adrenal gland hemorrhage that occurs after meningococcal sepsis infection, can lead to adrenal insufficiency

Waterhouse-Friderichsen syndrome