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Adrenal Incidentalomas

Matthew Gonzalez


  • Adrenal mass >1cm, discovered by chance on radiographic imaging

  • Less than 1% are malignant

  • Supportive of benign: <4 cm in size, smooth borders, homogenous appearance, <10 HU (Hounsfield units), rapid contrast washout (on "adrenal phase" imaging)

  • 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


  • All incidentalomas should be screened for pheochromocytoma (~3% incidence) before operative intervention

  • Cortisol secreting adenoma (~6% incidence) causing Cushing's syndrome: baseline serum DHEAS, low dose (1mg) overnight dexamethasone suppression test

  • 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


  • If benign appearing and not hormone producing: interval imaging in ~1 year, and repeat hormone work up

  • Unilateral adrenal incidentaloma

    • If progression free (stable size, and not hormone producing) can consider monitoring cessation after 4 years
  • Pheochromocytomas should undergo surgical evaluation for removal

    • Alpha blockade (phenoxybenzamine) + propranolol prior to resection to avoid HTN crisis
  • 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)

  • Cortisoloma: if clinically significant should undergo surgical removal, will need perioperative glucocorticoid administration to avoid iatrogenic adrenal insufficiency

  • Macroadenomas (masses >4 cm) are usually malignant and should be considered for surgical resection due to higher risk of carcinoma

Last update: 2022-06-20 12:09:37