Pituitary, Adrenal, MEN Flashcards Preview

Surgery > Pituitary, Adrenal, MEN > Flashcards

Flashcards in Pituitary, Adrenal, MEN Deck (49):
1

Location of pituitary gland + structures in proximity

Located in sella turcica in sphenoid bone
optic chiasm is anterior
hypothalamus is above
cranial nerves 3, 4, 5, 6 and carotid arteries are close by

2

What happens when pit tumor compresses optic chiasm?

Bitemporal hemianopsia (can't see on side in each eye)

3

Parts of the pituitary gland

Anterior lobe = adenohypophosis
Posterior lobe = neurohypophysis

4

Hormones of the anterior pit

Makes its own hormones:
FSH
LH
ACTH
TSH
Prolactin
GH
All under the control of hypothalamic hormones that travel directly from hypothal thru portal circulation to the anterior pit, which makes the hormones

5

Hormones of the posterior pit

These are made in the hypothalamus and then transported to the posterior lobe:
vasopressin (ADH)
oxytocin

6

T/F most prolactin-secreting tumors are not malignant

True

7

What is the difference between a prolactinoma that is a macroadenoma and one that is a microadenoma

Macro enlarges the pit gland, micro does not enlarge it.
Macro- more common in men
Micro- more common in women

8

What is the most common pituitary neoplasm?

Prolactinoma

9

HPE for prolactinoma

Macroadenomas usu cause headache as tumor enlarges.
Women- irreg menses, amenorrhea, galactorrhea
Extraocular mvmt deficits (3,4,6)

10

Dx Eval for prolactinoma

Serum prolactin >300ug/L = pit adenoma
if >100 it's suggestive
Use MRI to see micro vs macro

11

Rx for prolactinoma

Asx w micro- just follow.
If hyperprolactinemia- trial of bromocriptine or cabergoline
If drugs fail- transsphenoidal resection

If macro w compressive sx- bromocriptine (may decrs tumor size) and/or surgical resection.
Resection has high recurrence rates.
Can give radation for long term control but will get pan-hypo-pituitarism

12

What hormones does GH stimulate?

Stims production of growth-promoting hormones- somatomedin and insulinlike GH

13

Overproduction of GH leads to...

acromegaly
almost always dt pit adenoma

14

HPE of GH overproduction

sweating, fatigue, headaches, voice chg, arthralgia, jaw malocclusion, all over many years.
some pts have kidney stones
physEx for acromegaly- bony overgrowth of face/hands, rough features, increased nose, lips, tongue.
LVH and HTN

15

Dx eval of acromegaly

Serum GH elevated-
GH is NOT suppressed by insulin challenge- give insulin and GH should go down.. but it doesn't.
Do MRI to see lesion size.

16

Rx for acromegaly

Resection of tumor, radiation, and/or bromocriptine.
Surgery is better for pts w lower GH levels pre-op
Radiation can cause panhypopituitarism
Bromocriptine is usu not effective by itself

17

HPE for FSH and LH tumors

Headache/visual field defect from compression.
Tumors can be large, so may get panhypopituitarism.
Women have no hormonal sx. Men with FSH secreting tumors can have lower libido

18

Rx for FSH and LH tumors

Surgery to relieve compression- they can grow large.

19

Where are the adrenal glands located?

just above kidneys
anterior to the posterior diaphragm
R gland- lateral and just posterior to IVC
L gland- inferior to stomach, near pancreatic tail

20

Blood supply to adrenal glands?

Superior supra-adrenal (comes from inferior phrenic artery)
Middle supra-adrenal (comes from aorta)
Inferior supra-adrenal (comes from renal artery)

21

Venous drainage of adrenal glands?

R adrenal gland- to IVC
L adrenal gland- to renal vein

22

Structure of adrenal gland, what each part secretes

Cortex and medulla
Cortex- glucocorticoids (cortisol), mineralocorticoids (aldosterone), sex steroids
Medulla- catecholamines (epi, norepi, dopamine)

23

What is the precursor for glucocorticoids and mineralocorticoids?

Cholesterol- first it is converted to pregnenolone (rate limiting step)

24

What states stimulate cortisol production?

hypovolemia
hypoxia
hypothermia
hypoglycemia

25

How is cortisol secreted?

ACTH from the pituitary signals the adrenal cortex. ACTH was controlled by CRF (corticotropin releasing factor) which is secreted from the hypothalamus.

26

How does cortisol affect insulin and glucagon?

Stimulates glucagon rls
Inhibits insulin rls

27

What effects do exogenous (given) corticosteroids have?

immune suppression
impaired wound healing
block inflam cell migration
inhibit Ab production
inhibit histamine rls
inhibit collagen formation
inhibit fibroblast fn
(all of these are bad for pts that are on steroids for a long time)

28

How is aldosterone secretion controlled?

By renin-angiotensin system.
decreased renal bld flow or hyponatremia --> JG cells secrete renin
Renin cleaves ang to ang I
Ang I is cleaved to ang II
Ang II causes vasoconstriction and also causes aldosterone rls.
Aldosterone stims the distal tubule to reabs sodium --> increased water retention, restores circulating blood volume, bld prs

29

What is cushing's syndrome?

Overproduction of cortisol.
In 80%, it's dt ACTH hypersecretion.
In 80% of the ACTH hypersecretion pts, it's dt a pit adenoma (cushing's dz); other % is from other tumors- smlcc of lung, carcinoid tumors

Sometimes (10-20%), adrenal adenoma is the cause of the cortisol hypersecretion.

30

HPE of cushing's

weight gain, easy bruising, lethargy, weakness
appearance: truncal obesity, striae, hirsuitism
HTN, prox musc weakness, impotence/amenorrhea, osteoporosis, glucose intolerance, ankle edema

31

Dx Eval for cushings

24hr urine collection shows increased cortisol.
If ACTH levels are low- probably dt adrenal problem (bc cortisol suppresses ACTH)

Dexamethasone suppression (of ACTH) test-
in pts w pit microadenomas, dexamethasone CAN suppress ACTH production- but only from the pit. so if the source is adrenal or ectopic, it will not be suppressed.

32

Rx for cushings

remv source of increased cortisol production
pit- resect
adrenal- adrenalectomy if it's an adenoma; if carcinoma, resect.

33

What are the causes of hyperaldosteronism?

Adrenal adenoma in 80%
Idiopathic bilateral hyperplasia in 15%
adrenal carcinoma, ectopic production (rare)

34

HPE for hyperaldosteronism

Usu mild sx- fatigue and nocturia
HTN most common finding

35

Dx Eval for hyperaldosteronism

Hypokalema- bc sodium is absorbed in the distal tubule preferentially- so there is kaluresis (peeing out potassium)
Aldo lvls in serum and urine are increased
Serum renin is decreased.
CT or MRI to evaluate adrenals- if mass >1cm, probably neoplasm.

36

Rx for hyperaldosteronism

Surgical excision for adenoma
For carcinoma- excision and/or debulking + chemo.

If idiopathic bilat hyperplasia, give K+ sparing diuretics and dexamethasone.

37

T/F if an adrenal neoplasm secretes excess sex steroids and virilization occurs, this suggests malignancy.

True- Rx is surgical removal.

38

What pts are at risk for adrenal insufficiency?

Long-term steroid use.

39

HPE of adrenal insufficiency

abd pain, vomiting
obtundation, hypotension, hypovolemia, hyperkalemia --> shock, cardiac arrhythmias

40

If a surgical pt is at risk for adrenal suppression/insufficiency, what should you do?

Perioperative steroids.
Continue after surgery if pt is in critical condition.
MUST id pts before surg!

41

What is a pheochromocytoma?

Tumor that produces excess catecholamines (epi, ne, dopamine)

42

HPE for pheochromocytoma

headaches, tachycard, palpitations, anxiety, sweating, chest/abd pain, nausea

43

Dx eval for pheo

SBP can reach 300mmHg
Urine- elevated epi and ne, also their metabolites are elevated- metanephrine, normetanephrine, VMA.
CT/MRI for tumor location/size
If extra-adrenal tumor- use radioactive meta-iodo-benzyl-guanidine scan.

44

Rx for pheochromocytoma

Surgical removal- but prep pt first so no HTN crisis-
give Ablockers, then B blockers
Always give alpha first!! to prevent cardiovascular collapse

45

When should an incidental adrenal mass be excised?

if there is sxtic or biochemical evidence of activity
or if it's >4cm

46

What kind of lab workup should you do for an incidental adrenal mass?

24hr urine (for cortisol)
dex suppression test
serum Na, K
serum epi, ne and their metabolites

47

MEN I

3 Ps:
Parathyroid hyperplasia
Pancreatic islet cell tumors
Anterior pituitary adenomas

48

MEN IIa

MTC (med thyroid carc)
Pheo
Parathyroid hyperplasia

49

MEN IIb

MTC
Pheo
mucosal neuromas
+body habitus w thick lips, kyphosis, pectus excavatum