2/13 Adrenal Gland - Lubitz Flashcards

1
Q

adrenal gland

A

adrenal cortex (“gfr” & “deeper you go, sweeter it gets)

  1. zona glomerulosa → mineralocorticoids (salt)
  2. zona fasciculata → glucocorticoids (sugar)
  3. zona reticularis → androgens (sex)
    • androstenedione, DHEA

adrenal medulla → catecholamines

  • norepi, epi, dopamine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

endocrine causes of HTN

A

adrenal diseases

  • Cushing’s Syndrome (hypercortisolism)
    • thick violaceous striae, buffalo hump/dorsocervical fat pad, supraclavicular fat pad, abd obesity, moon facies, ecchymoses, hirsutism, acne
  • Conn’s Syndrome (hyperaldosteronism)
  • pheochromocytoma

this type of HTN is curable with surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cushing’s syndrome

signs/sx

A
  • DM, HTN
  • abnl fat deposition: central obesity, moon facies, dorsocervical and supraclavicular fat pads
  • skin abnormalities
    • violaceous striae, easy buising, acne, hirsutism
  • psych abnormalities
  • menstrual irregs, decr lebido in men
  • myopathy
  • osteoporosis
  • inf (reactivated TB, candidiasis, etc)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

regulation of ACTH and cortisol

A

hypothal: CRH → pit: ACTH → adrenal: cortisol

  • circadian pattern of release (highest cortisol in early am); sleep-wake cycle can alter release pattern
  • incr cortisol seen in physio and patho states
    • physio: stress, strenuous exercise, preg
    • patho: pseudo-Cushing’s, ACTH-dep CD, ACTH-indep CD, exogenous ACTH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

pseudo-Cushing’s syndrome

A

NOT primary overproduction of ACTH

instead, some stressor triggering overproduction of CRH/ACTH/cortisol

  • exercise
  • pregnancy
  • uncontrolled diabetes
  • sleep apnea
  • pain
  • alcoholism
  • psych disorders
  • stress
  • extreme obesity

tx: TREAT UNDERLYING CONDITION!!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Cushing’s Syndrome

dx

A
  • 24h urine free cortisol
  • dexamethasone suppression test (low dose)
    • high dose test used to see where ACTH is coming from
  • midnight cortisol
  • midnight salivary cortisol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

etiologies of Cushing’s Syndrome

A

ACTH-dependent (either form pit or from ectopic source)

  • Cushing’s Disease (pit) 68
  • ectopic ACTH syndrome (ex. sm cell lung cancer)

ACTH-independent (low ACTH, from adrenal glands)

  • adrenal adenoma 10
  • adrenal carcinoma 8
  • micronodular hyperplasia
  • macronodular hyperplasia

**MEDICATION (most common cause of Cushing’s)

  • oral, IM, inhaled, skin cream (rare)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Cushing’s Syndrome localization

A

Cushing’s Disease : from pituitary

Cushing’s Syndrome : from any source (even exogenous)

primary adrenal : over prod of cortisol

  • will actually dampen CRH and ACTH production through neg feedback
    sooo. ..measure plasma ACTH to diagnose location
  • if ACTH low → issue is adrenal glands (ACTH independent disease)
  • if ACTH high → issue is either pituitary or ectopic (ACTH-producing tumor)

to differentiate between pituitary or ectopic…

CRH stimulation test

  • no change in ACTH → ectopic source
  • shrink/decr in pit gland activity → pituitary source

high dose dexamethasone suppression test

  • no change in ACTH → ectopic source
  • depression of ACTH/cortisol prod → pituitary source

bilat inf petrosal sinus sampling (measure amt of ACTH in sinus vs in periphery)

  • more ACTH in periph → ectopic source
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

dexamethasone suppression tests

A

low dose

  • 1mg dex at 11pm, pl cortisol check at 8am
    • if pt has Cushing’s Syndrome (any cause), AM cortisol will not be suppressed

high dose

  • 8gm dex at 8am
    • if pt has Cushing’s Disease (pit source), AM cortisol will be suppressed to 50% baseline
      • if ectopic production, cortisol UNSUPPRESSED
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

ectopic ACTH production

A
  1. oat cell (sm cell) lung carcinoma
  2. thymoma
  3. pancr islet cell carcinoma
  4. carcinoid tumors (lung, gut, pancreas, ovary)
  5. thyroid medullary carcinomas
  6. pheochromocytoma and others
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Conn’s Syndrome

(primary mineralocorticoid excess)

etiology

clinical pres

A
  • bilat adrenal hyperplasia 60
  • aldosterone producing adrenal adenoma 40
  • adrenal carcinoma 1
  • glucocorticoid remediable hyperaldosteronism

presentation

  • HTN
  • hypoK
  • metabolic alkalosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

RAAS system graphic

A

remember: NO ROLE FOR THE PITUITARY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

dx of primary hyperald

tx

A
  • HIGH aldosterone level w LOW renin level
  • salt loading (oral or IV) to try to suppress aldosterone
  • localization
    • CT scan of adrenal glands; adrenal vein sampling

tx

  • unilateral adenoma? surgical resection
    • cant operate? medical tx
  • bilat hyperplasia? medical tx

medical therapy = SPIRONOLACTONE (aldosterone antagonist)

  1. anti-androgen (side effect: gynecomastia in men)
    • also used for PCOS for this effect!
  2. K sparing diuretic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

adrenal (cortex) insufficiency

types x3

dx: screening/confirmation

how to distinguish between primary and secondary adrenal insuff

A
  1. primary: Addison’s disease
    • lose all three layers of cortex → loss of mineralocorticoid, glucocorticoid, androgens
  2. secondary (pituitary)
    • loss of glucocorticoid >>> loss of androgen
    • RAAS is intact (bc pituitary has no role here!!!)
  3. tertiary (hypothalmic)

dx

  • screening: morning cortosol level (not good test)
  • confirmation: cortrosyn or cosyntropin stim test (synth ACTH)
    • WONT tell you whether its a pit problem or an adrenal gland prob…why? if the issue is pit, why would the adrenals not respond to synth ACTH?
    • if you dont have ACTH stimulating the adrenal gland daily, the adrenals deteriorate → i.e. won’t respond to synth ACTH in this case
    • sooo…how do you tell if its primary or secondary?
      • check ACTH level (not super helpful)
      • check RAAS (check K - will be high in primary! in secondary, K will be ok)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

adrenal insufficiency

key signs/sx

A
  1. cortisol deficiency
    • ​​wt loss, fatigue, weakness
    • anorexia, n/v, abd pain
    • fasting hypoglycemia, inability to excrete free water
    • decr responsiveness to catecholamines
  2. mineralocorticoid deficiency (in PRIMARY)
    • ​​inability to conserve Na/waste K → hypoNa, hyperK, dehydration, hypotn, azotemia, decr CO
  3. lack of androgenic steroids
    • ​​lack of axillary/pubic hair in women
  4. excess ACTH and MSH (in PRIMARY)
    • ​​hyperpigmentation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

why does adrenal insuff cause hyperpigmentation

A

ACTH made up 39 a.a.s

  • regulates adrenal cortex, synth of adrenocorticosteroids
  • alphaMSH (first 13 aa of ACTH) → stim melanocytes! darkens skin

therefore, overprod of ACTH can lead to hyperpig due to alphaMSH

17
Q

etiology of primary adrenal insuff

A
  • autoimmune (most common cause in U.S.)
  • infectious
  • hemorrhage
  • metastatic disease
  • drugs (either decr synth or incr catabolism)
  • familial
18
Q

adrenal hemorrhage in sepsis

(Waterhouse-Friderichsen Syndrome)

A
  • bacterial inf (classic: N. meningitidis)
  • progressive hypotension → shock
  • DIC with purpura
19
Q

secondary adrenal insufficiency

etiology

A
  • exogenous steroid admin (most common)
  • pituitary/hypothalamic disease
    • infiltrative tumor, granuloma
    • hemorrhage, autoimmune
  • surgery
  • congenital
20
Q

adrenal crisis

A

endocrine emergency!!!

presentation: SHOCK

  • fever, hypotension, vomiting, abd pain, anemia, renal failure, hypoglycemia, mental status changes, coma, death

tx: IV fluid, high dose IV glucocorticoids, IV mineralocorticoids (if primary)

21
Q

pheochromocytoma

A

disorder of adrenal medulla

pheo is derived from chromaffin cells (neural crest derivatives)

can be benign or malignant, isolated or familial

  • MEN2a or MEN2b
  • vHL
  • NF1
  • familial paranganlioma
  • uberous sclerosis
  • sturge Weber
  • ataxia telangectasia
  • Carney’s Triad
22
Q

MEN1

A
  1. pancreatic
  2. parathyroid
  3. pituitary
23
Q

MEN2a

A

ret proto-oncogenes

  1. pheochromocytoma
  2. medullary cancer of thyroid
  3. hyperparathyroidism

Marfanoid habitus

24
Q

MEN2b

A
  • pheochromocytoma
  • medullary cancer of thyroid
  • ganglioneuromas of tongue
25
Q

paragangliomas

A

pheochromocytomas developing in extra-adrenal paraganglia

26
Q

pheochromocytoma

5Ps

classical triad

A
  1. pressure: HTN 90
  2. pain: headache 80
  3. perspiration 71
  4. palpitation 64
  5. pallor 42
  6. paroxysms: 15-20min, daily-monthly, spontaneous

triad:

  • pain (headache)
  • perspiration
  • palpitations
27
Q

pheo dx

confirmation, localization

A

confirmation:

  • urine fractionated metanephrines, catecholamines
  • plasma metanephrines
  • urine vanillylmandelic acid (VMA)

localization

  • CT/MRI of adrenals
  • I-131 metaiodobenzylguanidine (MIBG) scan
28
Q

pheo tx

prep for tx

A

once diagnosed, surgery

prep:

  1. alpha blockade with phenoxybenzamine (1-2wk)
  2. beta blockade (at least 3d)

during surg:

  • aggressive bp and fluid management

why? bc if just beta blockade, unopposed alpha would lead to HTN crisis → death

29
Q

neuroblastoma

A
  • adrenal medullary disorder
  • derived from neuroblasts (pluripotent sympathetic cells), can occur anywhere along symp chain (neck → pelvis)
  • most common tumor dx < 1yr

presentation: abd distension, large abd mass assoc w fever, weight loss

  • elevated catecholamines 90
    • homovanillic acid elevated (bc DA breakdown pdt)
  • overexp of N-myc oncogene
  • variable course : can metastasize widely or spontaneously regress or dif into benign ganglioneuroma
30
Q

incidentaloma

A

adrenal mass usually incidentally discovered during imaging

HAVE TO WORK IT UP → could be fxal with subclinical sx

ddx:

  • benign cortical adenoma
  • cortisol secreting benign adrenocortical adenoma
  • aldosterone secreting benign adrenocortical adenoma
  • pheo
  • adrenocortical carcinoma
  • metastatic cancer
31
Q

adrenocortical carcinoma

A

rapid growth, irreg margins, bad prognosis (5 yr survival 20-35%)

  • mass effect (abd pain)
  • rapid onset of hypersecretion signs/sx
    • androgens (hirsutism, acne, amenorrhea, oily skin)
    • cortisol (Cushing’s)
    • aldosterone (hypoK)
    • estrogen (gynecomastia)
32
Q

adrenal hormone synthesis pathways

A

cholesterol → pregnenolone → progesterone (precursor for all 3 pathways)

  1. mineralocorticoid pathway → aldosterone
  2. glucocorticoid pathway → cortisol, hydrocortisone
  3. adrenal androgen pathway → androstenedione, DHEA

each layer of cortex makes the hormones it does due to more/less levels of the enzymes req for each pathway

33
Q

congenital adrenal hyperplasia

most common type

dx

A

disorders of adrenal steroid biosynthesis tesulting in glucocorticoid and mineralocorticoid deficiencies

  • bc of deficient cortisol synth, ACTH levels are increased → adrenal hyperplasia → overprod of steroids preceding blockage
  • all AUTOSOMAL RECESSIVE
  • “classic” syndrome at birth
  • “non-classic” dx later

most common: CYP21 (21-hydroxylase) deficiency (95%)

  • just makes a ton of male hormones
  • dx: w HIGH levels of 17-hydroxyprogesterone level
34
Q

11beta hydroxylase deficiency

A
  • cant make cortisol
  • make tons of DOC (most potent mineralocorticoid) → HTN, hypoK
  • adrenal androgen excess
35
Q

17alpha hydroxylase deficiency

A
  • cant make cortisol
  • mineralocorticoid excess
  • adrenal androgen deficiency (males → pseudoherm)