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Endocrine > Hypercortisolism > Flashcards

Flashcards in Hypercortisolism Deck (54):
1

What is the definition of Cushing's syndrome?

Complex resulting from prolonged supraphysiological concentrations of glucocorticoids

2

What is the width of the abdominal striae?

Greater than 1 cm

3

What causes the thin skin and poor wound healing with Cushing's?

Inhibition of fibroblasts

4

What muscles are particularly weak with Cushing'?

Proximal muscles

5

What are the two causes of insulin resistance with Cushing's?

DM2 or impaired glucose tolerance

6

What are the supraclavicular findings of Cushing's disease?

Fullness

7

What are the three endogenous causes of Cushing's?

Primary (adrenal issue)
Secondary (increased ACTH)
Tertiary (increased CRH)

8

What is the most common cause of Cushing's?

Iatrogenic exogenous steroid administration

9

ACTH independent cause of Cushing's = ?

Exogenous or primary

10

What are the ACTH dependent causes of Cushing's?

Pituitary or hypothalamic causes

11

What is the most common cause of ACTH dependent Cushing's?

Pituitary microadenoma (true Cushing's disease) from a mutated corticotroph cell

12

What are the common causes of ectopic ACTH production?

Bronchial or thymic carcinoid
SCLC

13

What are the ACTH levels of ectopic production of ACTH relative to Cushing's disease?

5-10x greater than pituitary ACTH overproduction

14

What other findings are common with ectopic ACTH production? (2)

-Hirsutism from adrenal androgen production
-hyperpigmentation from ACTH precursor

15

True or false: ectopically producing ACTH tumors cause hyperpigmentation

True

16

What are the two breakdown products of POMC?

ACTH
MSH

17

Are ectopic ACTh secreting tumors fast or slow onset?

Fast

18

Which are more common: adrenal adenoma or carcinomas? Are these usually unilateral, or bilateral?

Unilateral adenoma

19

What are the two major etiologies of bilateral adrenal disease?

Micronodular hyperplasia
Macronodular hyperplasia

20

What are the three major steps of diagnosing Cushing's?

1. Confirm hypercortisolemia
2. Determine subtype
3. Localize source of overproduction

21

Why is testing for Cushing's done as an outpatient?

Increased stress in the hospital may give false positives

22

What are the three major tests that can be done to assess for hypercortisolemia?

-24 hour urinary free cortisol excretion
-2300 salivary or serum cort
-Low dose dexamethasone suppression test

23

How is the low dose dexamethasone test performed?

Give Cort at 2300, return at 0800 to check ACTH levels

24

What are the ranges for normal, borderline, and high 24 hr urinary cortisol collection concentrations?

Less than 50 mcg: unlikely
50-150 = borderline
More than 150 = likely

25

True or false: a normal 24 urine collection test usually rules out Cushings

False-- may have a secretory type Cushing's

26

What, besides Cushing's, will cause an abnormally elevated 24 hours UFC?

Pseudo Cushing's

27

How can the 24 hour urine cortisol test be made more accurate?

done x4 over a month

28

What is pseudo-cushing's? Causes?

Underlying issue that stimulates that HPA axis

-EtOH-ism
-Depression
-Severe stress/surgery/infection

29

What is the medication that causes a decreased clearance of cortisol?

Carbamazepine

30

What is the best test to do on patients who may have pseudo-Cushing's?

Overnight low-dose Dexamethasone suppression test

31

Why is the midnight salivary cortisol testing useful to diagnose Cushing's?

Should be very low at this time, but Cushing's will disrupt the normal diurinal pattern

32

What are the ranges of the midnight salivary test for Cushing's?

-less than 5 mcg = no
-5-7.5 mcg = indeterminant
-More than 7.5 = likely cushing

33

What are the ranges of serum cortisol for the low dose dexamethasone test?

Normal = less than 2 mcg/dL
Indeterminant = 3-10 mcg/dL
More than 10 = Likely Cushing's

34

Hypercortisolemia + low ACTH = what?

Adrenal pathology

35

High ACTH + high cortisol levels = ?

Pituitary, hypothalamic, or ectopic pathology

36

What is the best way to assess for a pituitary problem causing hypercortisolemia? Adrenal? Ectopic?

-Pituitary = MRI the head
-Adrenal = CT the abo
-Ectopic = CT the chest

37

What is the treatment for adrenocortical adenomas? What are the complications that can arise from this?

-Surgical resection
-Atrophy of contralateral gland or pituitary corticotroph atrophy, leading to hypocortisolism

38

How malignant is adrenal carcinoma? Prognosis? Treatment?

Highly malignant
Poor
Surgical debulking, RT, non-specific chemo

39

What are the three etiologies of ACTH dependent Cushing's?

Pituitary, Hypothalamic, or ectopic tumor secreting ACTH

40

What are the two tests that can be performed to determine if a small pituitary mass is secreting ACTH?

-Inferior petrosal sinus sampling
-High dose dexamethasone test

41

What is the dose for low and high dose dexamethasone?

1 vs 8 mg

42

What is the role of the high dose dexamethasone test?

Pituitary will show partial suppression of ACTH, but ectopic will NOT

43

What is done with inferior petrosal sinus sampling?

Give CRH

Comparing the concentration of ACTH in the sinus vs the concentration of ACTH in the periphery--helps localize source of ACTH

44

What is the anatomic site of where the pituitary drains?

Petrosal sinus

45

What is the outcome of the Inferior pituitary sinus sampling test that will identify it as a pituitary source?

If IPS : P ratio is more than 2:1, then it is a pituitary source

46

What are the options for treating Cushing's disease?

Irradiation
Surgery
Adrenal surgery
Drug therapy

47

What is the indication of performing bilateral adrenalectomies in patients with an ACTH secreting pituitary adenoma?

If cannot remove the pituitary problem, then remove the source of cortisol

48

What is the mortality rate of pituitary surgery?

1%

49

What are the complications of pituitary surgery?

Anterior pituitary deficits
DI from post op swelling

50

What are the downsides of stereotactic radiosurgery on the pituitary? (2)

Slow therapeutic response
Post radiation panhypopituitarism

51

What is the use and MOA of aminoglutethimide?

Anticonvulsant that blocks the conversion of cholesterol to pregnenolone,

Leads to Decreased cortisol, aldosterone, and androgens

52

What is the use and MOA of ketoconazole?

Antifungal used to lock 11 beta hydroxylase to decrease cortisol, aldosterone, DHEA

53

What is the use and MOA of mitotane?

Blocks 11 beta hydroxylase
Decreases all cortical adrenal stuffz

54

What is the treatment for an ectopic site of ACTH production that is not well localized?

RT/chemo
Bilateral adrenal adrenalectomy
Meds