Adrenal Flashcards
(25 cards)
Catecholamine-producing tumors derived from the sympathetic or parasympathetic nervous system.
pheochromocytoma
These may arise sporadically or be inherited as features of
- multiple endocrine neoplasia type 2
- von Hippel–Lindau disease
- pheochromocytoma-associated syndromes
The clinical presentation is variable, ranging from an .
adrenal incidentaloma to a hypertensive crisis with associated cerebrovascular or cardiac complications
The mean age at diagnosis of pheochromocytoma is
40 y.o
The classic “rule of tens” for pheochromocytomas states that
- 10% are bilateral,
- 10% are extraadrenal,
- 10% are malignant.
well-vascularized tumors that arise from cells derived from the
- sympathetic (e.g., adrenal medulla)
- parasympathetic (e.g., carotid body, glomus vagale) paraganglia
Pheochromocytomas and paragangliomas
The name pheochromocytoma reflects the black-colored staining caused by___; although a variety of terms have been used to describe these tumors, most clinicians use this designation to describe symptomatic catecholamine-producing tumors, including those in extra-adrenal retroperitoneal, pelvic, and thoracic sites.
chromaffin oxidation of catecholamines
The term paraganglioma is used to describe ___ in the skull base and neck; these tumors may secrete little or no catecholamine.
catecholamine-producing tumors
- inactivation has been demonstrated for the VHL
- activate receptor tyrosine kinase activity.
- Biallelic gene
- RET mutations
reduce protein degradation, resulting in upregulation of components involved in cell cycle progression, glucose metabolism, and oxygen sensing.
VHL mutations
Its clinical presentation is so variable that pheochromocytoma has been termed
“the great masquerader”
typical clinical features and these manifestations constitute a classic triad of pheochromocytoma.
episodes of palpitation, headache, and profuse sweating
The presence of all three manifestations in association with ___ makes pheochromocytoma a likely diagnosis.
hypertension
can lead to heart failure, pulmonary edema, arrhythmias, and intracranial hemorrhage.
Catecholamine crises
The diagnosis is based on documentation of ___ by biochemical testing and localization of the tumor by imaging.
catecholamine excess
traditionally the first step in diagnosis of pheochromocytoma
measurement of catecholamines or metanephrines (their methylated metabolites)
Catecholamines and metanephrines can be measured by different methods
- high-performance liquid chromatography,
- enzyme-linked immunosorbent assay,
- liquid chromatography/ mass spectrometry.
re more convenient and include measurements of catecholamines and metanephrines.
Plasma tests
re the most sensitive and are less susceptible to false-positive elevations from stress, including venipuncture.
Measurements of plasma metanephrine
In this circumstance, it is important to exclude dietary or drug-related factors (withdrawal of levodopa or use of sympathomimetics, diuretics, tricyclic antidepressants, alpha and beta blockers) that might cause false-positive results and then to repeat testing or perform a
clonidine suppression test
Test that are of relatively low sensitivity and are not recommended.
phentolamine test and the glucagon provocation test,
similar in sensitivity and should be performed with contrast
CT and MRI
is optimal for detecting pheochromocytomas and is somewhat better than CT for imaging extraadrenal pheochromocytomas and paragangliomas.
T2-weighted MRI with gadolinium contrast
The primary treatment for a pheochromocytoma is
surgery to remove the tumor
