Pituitary/Adrenal Glands Flashcards
Enzyme converts to NE to epi?
PNMT, found only in adrenal medulla
Pheochromocytoma 10% rule
10% are: malignant, bilateral, in children, part of MEN, extra-adrenal (organ of Zuckerkandl at Ao bifurcation = most common)
Preop tx of pheochromocytoma
alpha block first, then beta block if tachycardic
Nelson syndrome
post adrenalectomy (10%), incr ACTH, pigmentation, vision changes from incr pituitary response
Waterhouse Friedrickson syndrome
adrenal hemorrhage a/w meningococcal sepsis
Conn’s syndrome
hyperaldosteronism = 80% adenoma, 20% bilateral hyperplasia (see with postural stimulation test). HTN, low K, high Na
Addison’s disease
low aldosterone and glucocorticoids = low Na, high K, hypoglycemia. Crisis presents similar to sepsis with hypoTN, fever; steroids are diagnostic and therapeutic ADDison’s = ADrenals Down
Congenital Adrenal Hyperplasia
21-hydroxylase deficiency = most common
Classic vision change with pituitary mass affect
Bitemporal hemianopsia
Chromophobe pituitary adenoma
non-functional, see decr GH, FSH, LH, TSH, ACTH
Sheehan syndrome
postpartum lack of lactation, persistent amenorrhea
Adrenal venous drainage left vs right?
Left: adrenal vein –> left renal vein Right: adrenal vein –> IVC
Three zones of adrenal cortex?
Glomerulosa: aldosterone Fasciculata: glucorticoids Reticularis: androgens
Adrenal medulla origin and produces what?
Neural crest Catecholamines: NE, epi, dopamine
Actions of angiotensin 2
Vasoconstriction Release of aldosterone: Na retention, K excretion
Primary hyperaldosteronism (Conn’s syndrome) sx, dx and tx
Sx: HTN, hypokalemia Dx: CT adrenal protocol, serum aldosterone:renin ratio is >30:1 Tx: >1 cm macroadenoma: lap adrenalectomy <1 cm: adrenal venous sampling hyperplasia: manage medically
Cushing syndrome sx
buffalo hump moon face central obesity
Cushing syndrome causes
ACTH secreting pituitary tumor Ectopic ACTH secreting tumor (small cell lung cancer) Adenomas: Cortisol producing adrenal tumors
Cushing syndrome dx
screening - 1 mg dex suppression test confirm - serum ACTH and DHEA levels low
Causes of primary adrenal insufficiency
MCC US: autoimmune MCC Worldwide: TB
Symptoms of adrenal insufficiency
Fatigue, anorexia, abd pain, skin hyperpigmentation
Addisonian crisis
Refractory shock CV collapse Dx: stim test Tx: treat empirically if high suspicion, can give dex so it does not interfere with stim test
When to tx an adrenal incidentaloma?
<4 cm with benign characteristic on CT scan: observe, repeat imaging in 6 months Functional, >6 cm, worrisome imaging: adrenalectomy 4-6 cm: individualized treatment Myeolipoma or cyst: does not need to be resected unless symptomatic
Adrenocortical carcinoma tx
Open adrenalectomy to avoid tumor spillage 60% are hyperfunctioning
Pheochromocytoma dx
Screening: plasma metanephrine Confirmatory: 24hr urine metanephrine
Pheochromocytoma tx
alpha-blockade (phenoxybenzamine) -> beta-blockade -> resect unopposed alpha stimulation = dangerously high blood pressures lap adrenalectomy or RP approach
MC site for extra-adrenal pheochromocytoma?
Organ of Zuckercandl - aortic bifurcation
What does alpha-1 receptor mediate?
Vasoconstriction Pupillary dilation Intestinal relaxation Uterine contraction
What does alpha-2 receptor mediate?
Vasoconstriction Feedback inhibition of NE release from sympathetic neurons Inhibits renin release and insulin release
What does beta-1 receptor mediate?
Increases force and rate of cardiac muscle contraction Increases lipolysis Increases amylase production
What does beta-2 receptor mediate?
Relaxes smooth muscle Increases glycogenolysis Increases insulin and glucagon secretion Increases renin secretion
Which familial syndromes are a/w pheochromocytoma?
Isolated familial pheochromocytoma MENIIa MENIIb Von Recklinghausen neurofibromatosis
Classic post-op complications after pheochromocytoma removal?
Persistent HTN Hypotension Hypoglycemia - decreased circulating catecholamines, increased insulin release Bronchospasm - decreased beta-2 activation
Recurrence rate of pheo after resection?
5-10% Monitor catecholamine levels annually for the first 5 years
What percentage of patients with VHL syndrome have a pheo?
50%
What should be done prophylactically in patients with known adrenal insufficiency undergoing surgery?
Stress dose steroids 100 mg cortisol IV on the day of surgery and then every 8hr Taper as tolerated post-op to maintenance dose
MEN Syndromes
Diamond, square, triangle
MEN I, IIA, IIB:
- Chromosome
- Inheritance pattern
- Medullary thyroid cancer?
- MTC course
- Parathyroid disease?
- Pheo?
- Phenotype
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