Adrenal cortex and cushing's syndrome Flashcards Preview

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Flashcards in Adrenal cortex and cushing's syndrome Deck (38):
1

Which steroids are produced by the adrenal cortex

Glucocorticoids
Mineralcorticoids
Androgens

2

Process of steroid hormone release

CRF-->ACTH-->steorid release, negative feedback

3

Definition cushing's syndrome (3 aspects)

+Glucocorticoid excess
Loss of negative feedback
Loss of normal cyclical pattern of GC relese

4

Chief cause of cushing's syndrome

Iatrogenic- oral steroids

5

80% of endogenous cushing's caused by, commonest endogenous

ACTH excess
Pituitary adenoma- cushings disease

6

Broad categories of cushing's

ACTH dependent
ACTH independent

7

ACTH dependent causes (2)

Cushings disease
Ectopic ACTH- Small cell lung, pancreatic, medullary thyroid
Rarely CRF tumor

8

ACTH independent causes (4)

Adrenal adenoma/cancer
Adrenal nodular hyperplasia
Iatrogenic

9

What is cushing's disease

Bilateral adrenal hyperplasia, due to +ACTH from pituitary microadenoma

10

Epidemiology in cushings disease

30-50 yo

11

How does low dose and high dose dexamethasone test change cortisol levels in CD

Low dose, no effect
High dose (>8mg) can halve morning cortisol levels

12

Specific features in ectopic ACTH production

Pigmentation
Hypokalemic metabolic alkalosis
Weight loss
Hyperglycemia

13

When ectopic ACTH, does high does dexamethasone suppress cortisol levels

No

14

Clinical features

Weakness
Insomnia
Mood disorders
Impaired cognition
Easy bruising
Oligo/Amenorrhea
Hirsutism and acne

15

Which symptoms are ACTH dependent

Hirsutism and acne

16

Signs

Central obesity
Mood face
Supraclabicular and dorsal fat pads
Facial plethora
Muscle wasting
Purple abdominal striae
Skin atrophy
Acanthosis nigricans
HTN
Hyperglycemia
Osteoporosis
Pathalogical fractures
Hyperpigmentation
Hyperandrogenism

17

Key diagnostic factors

Risk factors
Facial plethora
SC fat pads
Striae
Absence of pregnancy
Menstural irregularities
Absence of malnutrition, alcoholism
Absence of physiological stress
Linear growth deceleration in children

18

Strong risk factors

Exogenous cortisol use
Pituitary adenoma
Adrenal adenoma
Adrenal carcinoma

19

History

Iatrogenic steroid use
Features unusual for age->osteoporosis
Unexplained psychiatric
Nephrolithiasis
Multiple/progressive symptoms
PCOS
Pituitary adenomas
Adrenal adenomas

20

First line diagnostic test->use one of

Late night salivary cortisol >4nmol/L, at lease 2 readings
Overnight 1mg dex suppression testing >50nmol/L
24 hour urinary free cortisol-> >3 times upper limit of normal, at least 2 readings
48 hour 2mg dex suppression testing

Should repeat the diagnostic tests
Confirmed if any two are positive

21

Algorithm for cushing diagnosis

Cushings expected-->exclude exogenous-->Perform one of high sensitive tests

If negative->Cushings unlikely
If positive->exclude physiological causes->confirm positive test and perform 1 or 2 additional studies->referral to endocrinologist

If positive->cushings->measure plasma ACTH
If negative->cushings unlikely

Suppressed ACTH->independent of ACTH->imaging of adrenals
XSuppressed ACTH= ACTH-dependent-->MRI of pituitary

22

Physiological causes of cushing's

Physical stress
Malnutrition
Alcoholism
Depression
Pregnancy
Morbid obesity/metabolic syndrome

23

Other tests to perform

Glucose
Pregnancy

24

If a pituitary adenoma is found on MRI, at what size should you proceed to treatment

6mm

25

Management->ACTH secreting tumor

Transphenoidal pituitary adenomectomy
Adjunct:
Medical therapy prior to surgery--> mifepristone or pasiretide or ketoconazole
Post surgical cortisol replacement->hydrocortisone
Non-cortisol replacement->levothyroxine +/- testosterone, estrogen, medroxyprogesterone, somatotropin, desmopressin

26

What is pasireotide and how does it work

Somatostatin analogue->binds to receptor expressed by corticotrophs in adenomas->decreaseing cortisol

27

What tole does ketoconazole have

Steroidogenesis inhibitor

28

What is the role of mifepristone

Glucocorticoid receptor antagonist->blocks cortisol at receptor levels and attenuates effects of elevated cortisol

29

When treated with medical therapy before surgery, what must be monitored for

Adrenal insufficiency

30

Postoperatively what symptoms should be checked for

BP
Orthostatic hypotension
General sense of energy/fatigue

31

Which hormones may be needed (not including cortisol) post surgery

Levothyroxine
Testosterone
Estrogen + progestin (10 days/month)
?GH
Desmopressin

32

Other options for management of ACTH tumor

Repeat surgery
Pituitary radiotherapy
Bilateral adrenalectomy

33

Management of ectopic ACTH or CRH syndrome

Surgical resection/ablation of tumor/metastasis
Medical therapy- mifepristone, pasireotide, ketoconazole
Chemo/radiotherapy for primary tumor

34

Management of ACTH independent->unilateral adrenal carcinoma or adenoma

Unilateral adrenalectomy/tumor resection
Medical therapy before surgery
Chemo/radiotherapy for adrenal carcinoma

35

Management of ACTH independent due to bilateral adrenal disease

Bilateral adrenalectomy
Permanent post surgical corticosteroid replacement therapy
Medical therapy before surgery

36

Which conditions are unlikely to having clinical features of cushings

Physical stress
Malnutiriton
Anorexia
Intense chronic exercise
Hypothalmic amenorrhea
CBG excess

37

Interpreting high dose dexamethasone suppression test

8mg dexamethasone at 11pm- Next morning 8am cortisol Cushing syndrome of pituitary origin

38

What is the inferior petrosal sinus sampling for

Confirm side of hypersecretion