Endocrine Tumors Lecture Powerpoint Flashcards
The right adrenal gland’s main vein (right suprarenal vein) drains directly into the ___, the left drains ___
- vena cava
- renal vein
Layers of the adrenal gland and hormones secreted in each (4)
Zona Glomerulosa - aldosterone
Zona fasciculata - cortisol
Zona reticularis - androgens
Medulla - catecholamines
4 common extramedullary locations of pheochromocytoma (catecholamine secreting paragangliomas that only secrete norepi)
- Organ of Zuckerkandl (near bifurcation of abdominal aorta along spine)
- neck
- upper abdomen (most common)
- bladder
Classic triad of pheochromocytoma and another pathognomonic finding
- palpitations
- sweating
- headache
-feeling of impending doom
Other associated conditions with pheochromocytoma (3)
- MEN II a and B
- neurofibromatosis
- von hipple-lindau (retinal hemiangioblastomas, CNS hemiangioblastomas, multiple renal cysts)
Pheochromocytoma diagnostic studies (4)
- 24 hour catecholamine (metanephrine, norepi, VMA (most diagnostic))
- CT to localize
- MIBG (idonine scan where pheo takes up as well as thyroid so give Lugols solution)
- PET scan
Pheochromocytoma treatment options (1) and what is the pre op prep?
- surgical resection only (dissection with minimal tumor manipulation to prevent catecholamine surge, venous drainage first*** then arterial)
- Pre op prep involving preventing hypertension and tachycardia beginning 1 week before (alpha adrenergic antagonist like phenoxybenzamine THEN B receptor antagonist like propranolol
Aldosteronoma pathognomonic findings (2)
- hypertension
- hypokalemia (not on diuretics)
Recall the RAAS system
- at the level of the kidneys hypovolemia causes release of renin from juxtaglomerular aparatus
- angiotensinogen released from liver is converted by renin to angiotensin I
- angiotensin I is converted by lungs that release ACE into angiotensin II
- angiotensin II causes aldosterone secretion at the adrenal gland and has peripheral vasoconstriction effects
- aldosterone causes retention of sodium and therefore water but loss of potassium
Diagnostic labs of aldosteronoma (4)
- increased plasma aldosterone but decreased plasma renin (inappropriate release of aldosterone)
- rule out bilateral adrenal hyperplasia (unknown cause) via CT scan
- oral sodium loading (should suppress aldosterone secretion)
- captopril administration test (should cause decrease in adlosterone and increased renin but in primary hyperaldosteronism there is no change)
Cushing syndrome vs cushing dz
Syndrome is signs and symptoms associated with elevated cortisol level vs in cushing dz see pituitary tumor hypersecreting ACTH resulting in excess cortisol
Glucocorticoid producing tumor diagnostic studies (3)
- increased 24 hr urine free cortisol
- dexamethasone suppression test
- CT scan
Cushing syndrome signs and symptoms (8)
- weight gain
- peripheral muscle wasting
- hirsutism
- buffalo hump
- moon face
- menstrual irregularity
- amenorrhea
- impotence
Cortisol release pathway
- cortosol levels sensed in hypothalamus and releases CRH when low
- Anterior pituitary receives CRH and this stimulates release of ACTH
- this acts at the adrenal gland increasing cortisol in the blood stream to be sensed in hypothalamus
Cushings disease has __ ACTH and ___ cortisol, noncushings disease cushings syndrome has ___ ACTH and ___ cortisol
Elevated, elevated, low, elevated
Dexamethasone suppression test
-24 hr urine for 3 consecutive days, .5 mg of dexamethasone given every 6 hours on day 2 and 3, urinary free cortisol should be <10mcg/day on day 2, if not suppressed then must have adenoma
Adrenal cortex incidentaloma
Seen in patients often getting CT or screening for something else, if it isn’t presenting symptomatic then don’t need surgical intervention, can do fine needle aspiration after ruling out a pheo*** to determine cause
How far is the ampulla of vater from the pylorus
7cm
Majority of islets of langerhans cell types for the pancreas are located in what part of it?
The tail
Pancreatic islet cell tumors localization techniques (5)
- CT scan
- visceral angiography
- transhepatic portal venous sampling
- intraoperative exploration
- intraoperative ultrasound
Most common functional pancreatic endocrine tumor
Insulinoma
Whipples triad and what is it pathognomic of?
- symptoms of hypoglycemia, blood glucose level <50mg/dl, and relief of symptoms following ingestion of glucose
- pathognomonic of insulinoma
Diagnosis of insulinoma (3)
- insulin and glucose determinations during a 72 hr fast
- insulin to glucose ration >.3 after overnight fast
- elevated c peptide and proinsulin levels
Proinsulin is cleaved to insulin from removal of a free ___, measuring this rules out ___ insulin as a source
C peptide, exogenously injected
Zollinger Ellison syndrome/gastrinoma suspicious findings (5)
- ulcers in unusual locations (not antrum or prepyloric area)
- persistent ulcers despite medical management and chronic diarrhea
- ulcers and manifestations of other endocrine tumors
- strong family history of ulcer dz
- recurrent ulcers after antiulcer surgery
Gastrinoma diagnostic studies (2)
- fasting gastrin >200 or >1000 highly suspicious
- secretin stimulation increasing gastrin levels >200 is diagnostic***
Gastrinoma treatment options (2)
- control gastric hypersecretion (gastrin, Ach from vagus, histamine all contributors) so give PPI
- surgical localization, assess for mets, and remove
Pyramidal lobe of the thyroid
Remnant of thyroglossal duct sometimes present extends upward torward cricoid cartilage from isthmus
Thyroid arterial supply (2)***
- Inferior thyroid artery from the thyrocervical trunk
- Superior thyroid artery off carotid
Thyroid venous supply (3)***
- Inferior thyroid vein draining into subclavian
- middle thyroid vein (has NO arterial equivalent)
- superior thyroid vein draining into jugular
