Adrenal Nodule Monitoring Guidelines

Initial Hormonal Screening

The American Urological Association recommends that all patients with adrenal incidentalomas ≥1 cm must undergo a 1 mg overnight dexamethasone suppression test to screen for autonomous cortisol secretion, regardless of imaging characteristics or symptoms 1, 2, 3
For patients with hypertension and/or hypokalemia, the Endocrine Society recommends measuring plasma aldosterone-to-renin ratio to screen for primary aldosteronism, with a ratio >20 ng/dL per ng/mL/hr having excellent sensitivity and specificity for hyperaldosteronism 1, 2, 5
The American Urological Association recommends screening for pheochromocytoma only if the mass measures ≥10 Hounsfield Units (HU) on non-contrast CT or if symptoms of catecholamine excess are present, using plasma free metanephrines or 24-hour urinary metanephrines and normetanephrines 1, 2, 3

The Canadian Urological Association recommends reimaging at 12 months from diagnosis, then clinical follow-up annually for 4 years for benign-appearing adenomas <4 cm with <10 HU on non-contrast CT and normal hormonal workup 4
For benign-appearing adenomas 4-6 cm, the National Comprehensive Cancer Network recommends repeat imaging at 3-6 months, then at 6-12 month intervals for 1-2 years, with consideration of adrenalectomy if the mass enlarges by >1 cm in 1 year 4, 7
For indeterminate masses on initial imaging, the National Comprehensive Cancer Network recommends obtaining washout CT or chemical-shift MRI, then repeat imaging in 3-6 months, with continued annual imaging for 1-2 additional years if stable 4, 7

The Endocrine Society does not recommend repeat hormonal testing if initial values were normal for non-functional adenomas, but other guidelines such as AACE/AAES and CUA recommend annual hormonal panels for 5 years after diagnosis 4
For masses with growth >5 mm/year, the Praxis Medical Insights recommends repeat complete functional workup before considering surgical intervention 2

The European Society for Medical Oncology recommends follow-up every 3 months for 2 years with abdominal CT (or MRI), thoracic CT, and monitoring of initially elevated steroids for patients who underwent complete resection of adrenocortical carcinoma, with continued follow-up for at least 10 years due to risk of late recurrence 8
For patients who underwent successful surgery for pheochromocytoma, the European Society for Medical Oncology recommends repeat biochemical testing 14 days post-surgery to check for residual disease, then every 3-4 months for 2-3 years, followed by every 6 months thereafter, with lifelong surveillance recommended especially for patients with extra-adrenal primary disease, tumor size >5 cm, or SDHB mutations 8

The American Urological Association recommends not skipping dexamethasone suppression testing even in small, benign-appearing masses, as autonomous cortisol secretion is present in 5.3% of incidentalomas 3
The National Comprehensive Cancer Network recommends not performing adrenal biopsy routinely, only considering when diagnosis of metastatic disease from an extra-adrenal malignancy would change management, and always ruling out pheochromocytoma before biopsy to avoid precipitating a hypertensive crisis 1, 2, 3, 7
The Endocrine Society recommends not relying solely on CT imaging to distinguish unilateral aldosterone-producing adenoma from bilateral hyperplasia, as adrenal vein sampling is the gold standard 6, 1