Adrenal Disorders - Endo Flashcards
Pathophysiology Overview
Hyperadrenalism
- Hypercortisolism (Cushing’s Syndrome)
- Hyperaldosteronism
- Adrogenital (Virilizing) Syndrome
Hypoadrenalism
- Adrenal Insufficiency
- -acute (Adrenal Crisis)
- -chronic (1⁰=Addison’s Disease, and 2⁰)
Adrenal Neoplasm
-adenoma, carcinoma, pheochromocytoma
Hyperadrenalism
- Hypercortisolism (Cushing’s Syndrome)
- Hyperaldosteronism
- Androgenital (Virilizing) Syndrome
Hypercortisolism
nomenclature
- Cushing’s Syndrome = any cortisol excess
- Cushing’s disease = pituitary ACTH excess causing Cushing’s Syndrome
Etiology
-mcc = iatrogenic (when we prescribe exogenous corticosteroids)
other causes
-Cushing’s Disease (65%) - pituitary adenoma ↑ ACTH, which causes increased adrenal cortisol production
-Adrenal Tumor (25%) - usu an adrenal adenoma
-Ectopic ACTH Excess (10%) (aka Paraneoplastic Cushing’s Syndrome)- small cell lung cancer, pancreatic cancer, carcinoid
S/S
- Spontaneous bruising, proximal myopathy (type II fast-twitch m.fiber atrophy), striae, hypokalemia
- central obesity, round facies, dorsocervical fat pad, hirsutism
- DM, HTN, oligomenorrhea, osteoporosis
- Menstrual irregularities
- Round facies (moon facies)
- Central obesity/Cervical fat pad (buffalo hump)
- Urinary cortisol and glucose
- Striae, Skin thinning
- HTN, Hyperglycemia, Hirsutism, HypoK
- Immunosuppression
- Neoplasm of pituitary 2nd mcc (Cushing’s Dz)
- Glucose intolerance
Cushing work- up
1 of these initial tests
- 24hr Urinary Free Cortisol (UFC)
- Dexamethasone Suppression Test (DST)
- 11pm Salivary Cortisol (SC)
-if +, or – with high suspicion, repeat
-if still +, then check serum ACTH level
-low ACTH = adrenal tumor, get adrenal imaging
-nl or high ACTH, check 48hr high dose DST
-no suppression = consider Bilateral Inferior Petrosal Sinus vein Sampling (BIPSS) and think Ectopic ACTH
+ suppression = get pituitary MRI, consider BIPSS and think Cushing’s Disease
- check 24hr UFC or DST or SC
- if +, check ACTH levels
- if low ACTH, think Adrenal Tumor (so much cortisol release that is negatively feedback on the pituitary to decrease ACTH release)
- if nl or high ACTH, think Cushing’s Disease (a pituitary ACTH-secreting tumor) or an Ectopic Source of ACTH
- in either case, get imaging (pituitary, adrenals, or both, or lung)
Cushing - tx
- taper steroids if possible
- surgical resection of any tumor found
- pituitary adenoma, adrenal tumor, ectopic ACTH-secreting tumor
- if unsuccessful, consider pit-XRT or surgical B adrenalectomies or medical adrenalectomy with mitotane/Lysodren
- pt will then need lifelong gluco- and mineralocorticoid replacement therapy
- manage comorbidities of HTN, DM, obesity, infections
Hyperaldosteronism - etiology
primary
- adrenal hyperplasia (70%)
- adrenal adenoma (Conn’s Syndrome) (25%)
- adrenal carcinoma (5%)
secondary
-many; any renal-renin-secreting tumor (rare), renovascular dz, edematous states with decreased effective arterial volume (diuretics, CHF, cirrhosis, nephrotic syndrome)
Hyperaldosteronism - s/s, W/u, tx
S/S
- HTN (especially if multidrug resistant) and edema
- HA, weakness, polydipsia (due to hyperNa) -> polyuria
- abnl neuron and muscle action from hypoK
Labs
-mild hyperNa + classically hypoK (but often normal) + metabolic alkalosis
W/U
- screen anyone that has HTN (especially if refractory) + hypoK +/- adrenal mass
- check serum aldosterone levels, renin levels and plasma aldosterone:renin ratio
- high renin, high aldo = secondary hyperaldosteronism
- low renin, high aldo = primary hyperaldosteronism (adrenal hyperplasia/adenoma/carcinoma -> get imaging)
Tx
-correct underlying secondary cause
-surgical excision
i-f symptomatic, then spironolactone (aldo-antagonist)
Androgenital Syndrome
etio
- adrenocortical virilizing carcinoma
- congenital adrenal hyperplasia
- a group of autosomal recessive disorders with defective steroid biosynthesis, usu d/t a defective enzyme called 21-hydroxylase -> mainly decreases cortisol production
- decreased cortisol = ↑ pituitary ACTH = stimulation of adrenal gonadocorticoid production
S/S
-virilizing symptoms = female masculinization (ambiguous genitalia, hirsutism), male precocious puberty
Hypoadrenalism
Adrenal Insufficiency -acute (Adrenal Crisis) -chronic 1⁰ (Addison’s Disease) 2⁰
Acute Adrenal Insufficiency/Crisis - etiology
sudden withdrawal of exogenous steroids
- daily steroids can suppress the adrenal glands
- the patient becomes “dependent” on the po steroids
- if quickly stopped, it takes time for the suppression to be lifted, so the patient suffers adrenal insufficiency because their adrenals can’t make cortisol, and they aren’t getting any more by mouth.
-any physiological stress in a chronic adrenal insuff patient (tips them into acute insuff)
Waterhouse-Friderichsen Syndrome
-hemorrhagic adrenalitis commonly due to severe bacterial infection (mc = neisseria meningitidis)
- post B adrenalectomies or pituitary destruction
- post etomidate (used in intubation/anesthesia)
- meds: ketoconazole (antifungal)
Acute Adrenal Insufficiency/Crisis - s/s and tx
s/s
due to no cortisol
-weakness/fatigue, abdominal pain/N/V/D, confusion + orthostatic hypotension
due to no aldo
-ortho hypo, hyperK, hypoNa
Tx
- immediate volume resuscitation
- draw blood for cortisol level THEN IV hydrocortisone
- supportive, correct electrolytes
Chronic Adrenal Insufficiency - etiology
1⁰: some adrenal gland problem = Addison’s Disease
- autoimmune (80%)
- infection (namely TB or HIV)
- hemorrhagic adrenal damage during sepsis
- mets
- deposition diseases: hemochromatosis, sarcoid, amyloid
- 21-hydroxylase deficiency
2⁰: something other than an adrenal gland problem, namely a lack of ACTH production
-mainly due to daily exogenous glucocorticoids or any cause of hypopituitarism (any of the panhypopit etiologies)
Chronic Adrenal Insufficiency - s/s
due to no cortisol
-weakness/fatigue, weight loss, abdominal pain/N/V/D, myalgias/arthralgias, ortho hypo +/- anxiety and mental irritability
due to no aldo
-ortho hypo, hyperK, hypoNa
skin hyperpigmentation
-only present in 1⁰ insufficiency (when ACTH are chronically elevated, MSH production rises too)
+/- panhypopit sxs (see elsewhere)
Chronic Adrenal Insufficiency - w/u
- 8am cortisol level 18 rules it out)
- antiadrenal antibody assay
ACTH levels
- ↑increased in 1⁰ insufficiency (Addison’s) because there is an absence of cortisol, which means a loss of neg feedback to the hypothal -> ↑ ACTH
- ↓ or low-nl in 2⁰ insufficiency (this is the definition of 2⁰ insuff)
Cosyntropin Stimulation test
- cosyntropin is a synthetic ACTH
- given intramuscularly, then serum cortisol checked 45 mins after
- if serum cortisol rises, then etiology is 2⁰ and not Addison’s
Chronic Adrenal Insufficiency - tx
-correct secondary causes if possible
hormone replacement therapy
- daily hydrocortisone
- daily fludrocortisone is a better Na-sparing agent
- may be better for refractory ortho-hypo and hypoNa/hyperK
- DHEA given to some
- IM dexamethasone syringe for self application in emergency (a chronic adrenal insuff pt who gets into an acute phase, like an acute infection)
