disorders of the adrenal glands Flashcards
1
Q
List the 3 sections of the adrenal cortex and what each produces
A
- zona glomerulosa: mineralocorticoids: aldosterone
- zona fasciculata: glucocorticoids: cortisol
- zone reticularis: adrenal androgens: mostly DHEA
2
Q
cortisol is excreted in the urine in what form
A
17 hydroxysteroid (17OHS)
3
Q
androgen is excreted in the urine in what form
A
17 ketosteroids (17KS)
4
Q
what is the sign and symptom complex resulting from prolonged expsore to glucocorticoid hormones
A
cushings syndrome
5
Q
List the causes of ACTH-dependent cushing’s syndrome
A
- excessive ACTH production from pituitary (pituitary adenoma): most common cause
- ectopic ACTH producing tumor
- small cell lung CA is most common
- excessive CRH production from hypothalamus
6
Q
List the causes of ACTH-independent cushing’s syndrome
A
- adrenal tumor
- neuroendocrine tumors
- pheochromocytoma
7
Q
which type of cushing’s syndrome, ACTH dependent or independent, is more common? Is it more likely in males or females
A
- ACTH dependent: 70%
- 8-10x more likely in females
8
Q
clinical presentation
- weight gain/obesity
- facial plethora “moon face”
- truncal obesity with extremity wasting
- buffalo hump
- fatigability and weakness
- mostly proximal muscles
- abdominal straie
- acne and abnormal hair growth
- edema
- HTN
- insulin resistance
- vertebral fx, hypercalcuria, kidney stones
- dysphora, depression, paranoia
A
cushing’s syndrome
9
Q
What two hormone levels do you get to work up possible cushing’s syndrome
A
- plama cortisol level
- 8AM
- 4PM
- serum ACTH level
- 8AM
- 4PM
10
Q
what is an abnormal result for plasma cortisol level
A
- > or = 25 ug/dl at 8 AM
- less than the anticipated drop of 1/3 to 2/3 at the 4PM reading
11
Q
what is abnormal serum ACTH levels
A
- > 80 pg/ml at 8am; >50 pg/ml at 4pm
- < 20 pg/ml at any time
12
Q
Are cortisol and ACTH levels expected to be high or low in ACTH independent
A
- cortisol: high
- ACTH: low
13
Q
Are cortisol and ACTH levels expected to be high or low in ACTH dependent
A
- cortisol: high
- ACTH: high
14
Q
Why is 11-deoxycortisol measured at 8am when working up for cushing’s syndrome
A
- 11-deoxycortisol is a cortisol precursor
- it should be converted to cortisol and be undetectable at 8am
15
Q
What is the gold standard for screening for cushing’s syndrome? What is an abnormal result
A
- Dexamethasone suppression test (DST): given at night, expect ACTH and cortisol levels to be low the next morning
- abn result: cortisol > 5 ug/d is highly suspicious
16
Q
What is the main stay for diagnosis for cushing’s syndrome? What is an abnormal result
A
- 24 hour urine free cortisol
- measures 17-OCHS
- abnormal: cortisol > 125 ug/d is indicative of cushings
17
Q
describe salivary sampling used to work up cushing’s syndrome or adrenal insufficiency
A
- free cortisol diffuses freely into saliva
- sample saliva obtained after rinsing mouth but before brushing teeth at
- 9:00 am 3 mornings in a row when evaluating for adrenal insufficiency
- 11:00pm 3 nights in a row when evaluating for cushing’s syndrome
18
Q
abnormal results for salivary sampling in cushing’s syndrome vs adrenal insufficiency
A
- cushing’s syndrome: late evening salivary cortisol elevated
- adrenal insufficiency: morning salivary cortisol low
19
Q
MOA of Mitotane
A
- induces permanent destruction of the adrenocortical cells
- AKA medical adrenalectomy
20
Q
MOA of Ketoconazole in cushing’s syndrome? major side effect?
A
- antifungal with cortisol-reducing effects in higher doses
- liver toxicity
21
Q
MOA of Metyrapone in cushing’s syndrome?
A
- inhibits cortisol synthesis
22
Q
What is the most common cause of cushing’s syndrome
A
ACTH producing pituitary adenoma
23
Q
What is the most common cause of cushingoid symptoms
A
exogenous steroid use
24
Q
what is the inadequate production of mineralocorticoids, glucocorticoids, and or sex androgens
A
- adrenal insufficiency
- when all three are present -> addison’s disease
25
what is the most common cause of primary adrenal insufficiency
addison's disease: autoimmune destruction of adrenal gland
26
what are some infectious agents that can cause adrenal insufficiency
* histoplasmosis
* TB
* coccidiodomycosis
27
What is the most common cause of secondary adrenal insufficiency
* suppression of HPA axis through abrupt cessation of exogenous steroid
28
list drugs that reduce corticosteroids and can cause secondary adrenal insufficiency
* phenytoin
* opiates
* ketoconazole
* rifampin
29
list the hallmark tetrad of adrenal insufficiency
* **weakness/fatigue**
* **weight loss/anorexia**
* **hyperpigmentation**
* **hypotension (orthostatic)**
30
clinical presentation suggest deficiency in which hormone
* weakness
* fatigue
* hypoglycemia
* weight loss
* anorexia
* nausea
* vomiting
* abd pain
glucocorticoid deficiency
31
clinical presentation suggest deficiency in which hormone
* Na++ wasting
* hyponatremia, salt craving
* hypovolemia
* orthostatic hypotension
* hyperkalemia
* mild metabolic acidosis
Mineralocorticoid deficiency
32
clinical presentation suggest deficiency in which hormone
* loss of axillary and pubic hair in females
* amenorrhea
adrenal androgen deficiency
33
What is an abnormal result in the plasma cortisol level in the work up for adrenal insufficiency
* \< 5 ug/dl in the AM
34
What is an abnormal result in the serum ACTH level in the work up for adrenal insufficiency
* \> 80 at 8am; \> 50 at 4 pm
* \< 20 at any time
35
what do you expect cortisol and ACTH levels to be in primary and secondary adrenal insufficiency
* primary (addison's disease: cortisol low, ACTH high
* secondary: corticol low, ACTH low
36
explain the Cosyntropin stimulation test
* evaluates the ability of the adrenal gland to respond to ACTH administration: **gold standard for diagnosis**
* procedure
* obtain baseline cortisol level
* administer bolus of ACTH
* measure cortisol at 30 min and 60 min
* abormal result: cortisol level fails to increase \> 18 mcg/dl
37
What is the benefit of the Metyrapone stimulation test
* can be completed while on glucocorticoid supplementation
38
what is an abnormal response on the Metyrapone stimulation test in regards to 24 hour 17-OCHs excretion, serum cortisol, plasma ACTH, and serum 11-deoxycortisol
* 24 hour 17-OCHs excretion: less than doubling from baseline
* serum cortisol: \> 5
* plasma ACTH: \< 75
* serum 11-deoxycortisol: \< 7
39
Management of glucocorticoid deficiency
* hydrocortisone
* prednisone
* dexamethasone
40
Management of mineralcorticoid deficiency
fludrocortisone
41
Management of adrenal androgen deficiency
* DHEA
42
What should be done to the dose of glucocorticoids in the face of highly stressful events
increase dose
43
Two causes of primary hyperaldosteronism (Conn's syndrome)
* adrenalcorticol adenoma
* cortical hyperplasia
44
elevated plasma and urine aldosterone, low plasma renin levels are indicative of
primary hyperaldosteronism (Conn's syndrome)
45
management of primary hyperaldosteronism (Conn's syndrome)
* surgical removal of adenoma
* medical = spironolactone and antihypertensive agents
46
clinical presentation
* HTN
* hypokalemia
* muscle weakness
* paresthesias
* HA
* polyuria and polydipsia
primary hyperaldosteronism (Conn's syndrome)
47
What is a pheochromocytoma
* rare, catecholamine-producing tumor of neurochromaffin cells
* 10-15% malignant
* fatal if undiagnosed and untreated
48
extra-adrenal pheochromocytomas are called
paragangliomas
49
majority of pheochromocytomas arise from
adrenal medulla
50
pheochromocytomas can also occur in what autosomal dominant hereditary syndromes
* MEN2
* von hippel-lindau syndrome
* neurofibromatosis type 1
51
pheochromocytomas is characterized by classic paroxysm attacks of
* **HA**
* **sweating**
* **palpitations**
* **profound acute HTN at the time of episode**
* usually last 30-40 min
* may be precipitated by displacement of abdominal contents
* tend to increase in frequency and severity over time
52
what test is used to definitively diagnose pheochromocytomas
* clonidine suppression test
53
clonidine suppression test procedure
* stop hypotensive meds x 24 hours, fast overnight
* baseline BP, pulse and labs taken
* administer clonidine
* continue to monitor BP, pulse, and labs
* results:
* expect suppression of NE and epi
54
tx for pheochromocytoma
* IV nitroprusside for crisis
* chemical sympathectomy: pure alpha blocker, then beta blocker
* surgical excision is definitive tx
55
what is the rule of 10s in Pheochromocytoma
* 10% w/o HTN
* 10% extraadrenal
* 10% extraabdominal
* 10% children
* 10% familial
* 10% bilateral
* 10% metastatic disease at diagnosis
56
after the initial workup for pheochromocytomas, what should be done
* anatomic localization
* CT, MRI, PET, MIBG scan, OctreoScan
57
what is a adrenal incidentaloma
* mass lesion greater than 1 cm discovered incidentally by radiologic exam
* prevalence higher in obese, HTN, and DM patients
* 85-90% are non-functional
58
an adrenal incidentaloma that is lipid rich is more indicative of a
benign lesion
59
evaluation of hormonal secretion after finding a adrenal incidentaloma
* plasma cortisol, serum ATCH, serum DHEA, plasma aldosterone
* sxs of cushing?
* yes: 24 hr urinary free cortisol
* no: 1 mg overnight dexamethasone suppression
* suspicion for pheo?
* 24 hr urine metanephrines, catecholamines
60
when is a fine needle aspiration indicated in adrenal incidentaloma
* if primary malignancy elsewhere
* dont use if
* evidence of pheo
* known widespread metastatic dz
61
when is resection indicated for adrenal incidentaloma
* \> 2 cm
