Evaluation of Adrenal Masses

Introduction to Adrenal Mass Evaluation

The American College of Radiology recommends that all adrenal incidentalomas undergo biochemical evaluation for hormonal hypersecretion and radiological characterization using non-contrast CT as the first-line study 1
The American Urological Association suggests that all patients with adrenal incidentalomas ≥1 cm should undergo hormonal screening, regardless of imaging characteristics or symptoms 1, 2

The Endocrine Society recommends a 1 mg dexamethasone suppression test to detect autonomous cortisol secretion, with a cortisol level ≤50 nmol/L (1.8 μg/dL) excluding hypersecretion, 51-138 nmol/L (1.9-5.0 μg/dL) suggesting possible autonomous secretion, and >138 nmol/L (>5.0 μg/dL) indicating hypersecretion 1, 2, 3
The American Heart Association indicates that the aldosterone-to-renin ratio is useful in patients with hypertension and/or hypokalemia, with a ratio >20 ng/dL per ng/mL/hr having excellent sensitivity and specificity for hyperaldosteronism 1, 2
The National Institutes of Health recommends that plasma metanephrines or 24-hour urinary metanephrines/normetanephrines be measured if the mass has ≥10 HU on non-contrast CT or if there are symptoms of catecholamine excess (episodic hypertension, headache, palpitations, diaphoresis) 1, 2

The American College of Radiology suggests that non-contrast CT is the initial study of choice to distinguish benign from potentially malignant lesions, with homogeneous, well-circumscribed lesions with <10 HU being benign adenomas that do not require further imaging studies 1, 4, 5
The Society of Radiologists in Ultrasound recommends that CT with contrast washout be used to evaluate indeterminate masses, with adenomas demonstrating rapid washout (>60% absolute washout or >40% relative washout at 15 minutes) 1, 5

The Endocrine Society recommends a focused clinical history and physical examination to identify signs and symptoms of hormonal excess, including Cushing's syndrome (weight gain, central obesity, moon face, buffalo hump, purple striae, easy bruising, proximal muscle weakness, hypertension, diabetes, osteoporosis) 1, 3
The American Heart Association indicates that patients with primary aldosteronism may present with resistant hypertension, hypokalemia, muscle weakness, and cramps 3

The American Urological Association recommends that biopsy of an adrenal mass should not be performed routinely, but rather only when diagnosis of metastatic disease from an extra-adrenal neoplasm would be of clinical value 1, 3
The Society of Surgical Oncology suggests that a multidisciplinary team approach be considered when the imaging is not consistent with a benign lesion, there is evidence of hormonal hypersecretion, the tumor has grown significantly during follow-up (>5 mm/year), or adrenal surgery is being considered 1, 3

The American College of Radiology recommends that masses <3 cm are likely benign, but endocrinological evaluation should be considered since 5% have subclinical hyperfunction 6
The Society of Radiologists in Ultrasound suggests that masses 3-5 cm should undergo CT follow-up and chemical shift MRI 6
The American Urological Association recommends that masses >5 cm should be removed due to a higher risk of malignancy 6