Adrenal Incidentalomas¶
Matthew Gonzalez
Background¶
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Adrenal mass >1cm, discovered by chance on radiographic imaging
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Less than 1% are malignant
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Supportive of benign: <4 cm in size, smooth borders, homogenous appearance, <10 HU (Hounsfield units), rapid contrast washout (on "adrenal phase" imaging)
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Supportive of malignancy: >4 cm in size, irregular borders, > 20 HU on unenhanced CT, delayed contrast washout, tumor calcifications, increase in size over time, presence in young pts and hx cancer
Evaluation¶
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All incidentalomas should be screened for pheochromocytoma (~3% incidence) before operative intervention
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Cortisol secreting adenoma (~6% incidence) causing Cushing's syndrome: baseline serum DHEAS, low dose (1mg) overnight dexamethasone suppression test
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Aldosterone secreting adenoma (<1% incidence) causing hyperaldosteronism: if hypertensive (HTN) or hypokalemic order plasma aldosterone and renin, confirmatory testing with sodium loading (oral vs IV) and 24-hour urine aldosterone, sodium, and creatinine
Management¶
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If benign appearing and not hormone producing: interval imaging in ~1 year, and repeat hormone work up
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Unilateral adrenal incidentaloma
- If progression free (stable size, and not hormone producing) can consider monitoring cessation after 4 years
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Pheochromocytomas should undergo surgical evaluation for removal
- Alpha blockade (phenoxybenzamine) + propranolol prior to resection to avoid HTN crisis
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Aldosteronoma: should undergo surgical evaluation for definitive treatment; if unable to undergo surgery can treat with medical management with long term mineralocorticoid antagonist (e.g. spironolactone)
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Cortisoloma: if clinically significant should undergo surgical removal, will need perioperative glucocorticoid administration to avoid iatrogenic adrenal insufficiency
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Macroadenomas (masses >4 cm) are usually malignant and should be considered for surgical resection due to higher risk of carcinoma