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CC Sept 2017 Pheochromocytoma

echoecho's version from 2018-04-30 00:43


Question Answer
Define?rare neuroendocrine tumors that arrise from chromaffin cells in the adrenal medulla (85% of cases) or in sympathetic or parasympathetic ganglia
Which gender are they seen in more?occur with equal frequency in men and women
What decade of life are they seen most in?3rd to 5th decades of life
How many cases per million per year are seen in the USA?2-8 cases
What is the prevalence ranges among patients w/ HTN?prevalence ranges between 0.1% and 0.6%
*** About 1/3 of cases occur as part of hereditary syndromes, names 3?1) Hippel-Lindau syndrome 2) multiple endocrine neoplasia type2A and 2B 3) neurofibromatosis type 1
What is the oft described "rule of tens"? These numbers are anecdotal and do not apply to pheochromocytomas due to what?1)refers to 10% malignancy rate, 10% bilateralism and 10% occurring outside the adrenals 2) hereditary syndromes
What do pheochromocytomas release?catecholamines (norepinephrine, epinephrine and dopamine) in a periodic pattern that is responsible for usual symptoms
What is the symptom presentation?1) headache 2) palpitations 3) diaphoresis 4) severe high blood pressure
What is the duration of these symptoms?occur in episodes lasting minutes to hours that may be several months apart or occur several times a day
Can the HTN be sustained or episodic?yes
List other associated symptoms?1) nausea 2) weakness 3) anxiety 4) tremor 5) epigastric pain
These paroxysms may lead to life-threatening?1) HTN 2) heart failure 3) pulmonary edema 4) intracranial hemorrhage 5) fatal arrhythmias
List precipitating events that can precipitate pheochromocytomas?1) surgery 2) positional change 3) exercise 4) pregnancy 5) use of medications (TCAs, opiates or metoclopramide)
A pheochromocytoma may be asymptomatic for several years or discovered on imaging performed for other indications, true or false?true
Dx of pheochromocytomas require documentation of elevated levels of what?catecholamines
While these levels are markedly elevated during acute paroxysms, are they continually produced at abnormally high levels and can be detected even when patients are asymptomatic?yes
The diagnostic test of choice is what?Elevated fractionated metanephrines and catecholamines in a 24 hour urine collection
What is the sensitivity and specificity of this 24 hour urine collection test?98%
Can plasma tests for catecholamines and free metanephrines be used?yes (more convenient to obtain)
Why should a CT or MRI be obtained only AFTER biochemical confirmation of the disease?because of the relatively high prevalence of adrenal nodules
What is the treatment of pheochromocytoma?1) surgical excision 2) perioperative medical therapy is imperative and includes alpha-blockers for blood pressure control (typically started at least 7 days prior to surgery) 3) IV hydration 4) liberal salt intake
When should beta-blockers only be used?should only be used following administration of alpha-blockers (if there is persistent HTN or tachycardia)
Most pheochromocytomas aren paragangliomas are _____ (benign vs cancerous)? What is the long-term prognosis?1) benign 2) excellent prognosis
*** SUMMARY = Pheochromocytoma is a _______-secreting tumor arising in the adrenal medulla or in cells derived from the sympathetic or parasymptomatic paraganglia?catecholamine
*** SUMMARY = Most tumors are benign and sporadic but may also in association with various _____ syndromes and genetic mutations?hereditary
*** SUMMARY = Adrenal imaging is performed only AFTER demonstration of elevated ______ and _______?1) metanephrines 2) catecholamines
*** SUMMARY = What is the therapeutic goal?complete surgical excision