ADRENOMEDULLARY DYSFXN Flashcards
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What is pheochromocytoma (PHCM)?
PHCM is a tumor of the adrenal medulla that secretes catecholamines
What percentage of pheochromocytomas are malignant?
Approximately 10% of pheochromocytomas are malignant
What are the common clinical features of pheochromocytoma?
Features include hypertension
What is the clonidine suppression test used for?
It evaluates pheochromocytoma by suppressing catecholamine release in normal subjects but not in affected patients.
What is the treatment for pheochromocytoma?
The primary treatment is surgical removal of the tumor
What dietary restrictions are required before biochemical tests for pheochromocytoma?
Patients should avoid foods like bananas
What is the significance of metanephrine measurement in pheochromocytoma diagnosis?
Metanephrines are reliable markers for pheochromocytoma
What imaging modalities are used to localize pheochromocytomas?
CT
What are APUD tumors?
APUD tumors are a group of neoplasms
What are paragangliomas?
Paragangliomas are extra-adrenal pheochromocytomas found in chromaffin tissues derived from neuroectoderm.
What is the role of metyrosine in pheochromocytoma management?
Metyrosine inhibits catecholamine synthesis and is used pre-operatively to reduce tumor activity.
What biochemical tests are used for pheochromocytoma screening?
Tests include measurements of catecholamines
What is the prognosis of benign pheochromocytoma after surgery?
The 5-year survival rate exceeds 95%
What is the importance of follow-up in pheochromocytoma patients?
Follow-up includes monitoring catecholamine levels and blood pressure to detect recurrence or persistent hypertension.
What are the complications of untreated pheochromocytoma?
Complications include severe hypertension
What is multiple endocrine neoplasia (MEN) syndrome?
MEN is a hereditary disorder associated with endocrine tumors
What is the common cause of carbohydrate intolerance in pheochromocytoma patients?
It is due to catecholamine-induced insulin suppression and increased hepatic glucose output.
What are the features of malignant pheochromocytoma?
Features include metastases
What are the indications for genetic testing in pheochromocytoma?
Genetic testing is indicated in cases of bilateral tumors
What are the dietary sources that can interfere with biochemical tests for pheochromocytoma?
Bananas
What is the common cardiovascular manifestation in pheochromocytoma?
Hypertension
What role does histamine play in pheochromocytoma paroxysms?
Histamine can precipitate severe paroxysms by causing catecholamine release from the tumor.
How does a pheochromocytoma crisis typically present?
Crisis presents with abrupt onset of headache
What are the common catecholamines secreted by pheochromocytomas?
Adrenal pheochromocytomas secrete epinephrine and norepinephrine
How does clonidine suppress catecholamine secretion in normal subjects?
Clonidine inhibits catecholamine release via central alpha-2 adrenergic receptors but fails to suppress secretion in pheochromocytoma.
