From the Guidelines
The workup of an adrenal nodule should begin with a focused history and physical examination, followed by a non-contrast CT scan as first-line imaging to distinguish benign lesions from those requiring further radiologic investigation, as recommended by the most recent guideline endorsed by the AUA 1. The initial evaluation should aim to identify signs/symptoms of adrenal hormone excess, adrenal malignancy, and/or extra-adrenal malignancy.
- A low threshold for multidisciplinary review by endocrinologists, surgeons, and radiologists is recommended when the imaging is not consistent with a benign lesion, there is evidence of hormone hypersecretion, the tumor has grown significantly during follow-up imaging, or adrenal surgery is being considered 1.
- All patients with adrenal incidentalomas should be screened for autonomous cortisol secretion using 1 mg dexamethasone suppression testing as the preferred screening test 1.
- Patients with adrenal incidentalomas and hypertension and/or hypokalemia should be screened for primary aldosteronism with an aldosterone-to-renin ratio, and adrenal vein sampling is recommended prior to offering adrenalectomy in patients with primary aldosteronism 1.
- For patients with adrenal incidentalomas that display >10 HU on non-contrast CT or who have signs/symptoms of catecholamine excess, screening for pheochromocytoma with plasma or 24-hour urinary metanephrines is recommended 1.
- Adrenalectomy should be performed for patients with unilateral cortisol-secreting adrenal masses, aldosterone-secreting adrenal masses, and pheochromocytomas, with minimally-invasive surgery (MIS) being the preferred approach when feasible 1.
- The management of indeterminate non-functional adrenal lesions should involve shared decision-making between patients and their clinicians, considering options such as repeat imaging or surgical resection 1.
From the Research
Adrenal Nodule Workup
- The workup for adrenal nodules typically involves evaluating for hormonal activity, including a 1-mg overnight dexamethasone suppression test, total 24-hour urinary metanephrines and fractionated catecholamines, and, in the hypertensive patient, a serum potassium level and plasma aldosterone concentration to plasma renin activity ratio 2
- A study found that nodule length and width were the only two variables that significantly differed between patients with nonfunctional nodules and those with possibly or definitely functional nodules, with a nodule length threshold of 1.5 cm providing 93.1% sensitivity for predicting possible or definite autonomous cortisol secretion 3
- Autonomous cortisol secretion in patients with adrenal nodules correlates with increasing nodule size, and a nodule length threshold of 1.5 cm can be used to predict possible or definite autonomous cortisol secretion 3
Diagnostic Tests
- The dexamethasone suppression test (DST) is the standard method to diagnose autonomous cortisol secretion (ACS) from an adrenal adenoma 4
- A study found that low basal dehydroepiandrosterone sulfate (DHEAS) is a sensitive and specific screening test for subclinical hypercortisolism in adrenal incidentalomas, with a ratio of 1.12 being sensitive (>99%) and specific (91.9%) for the diagnosis of subclinical hypercortisolism 5
- Measuring plasma metanephrine during adrenal venous sampling (AVS) may help overcome the issue of concurrent hypercortisolism confounding AVS results in patients with primary aldosteronism 6
Management
- All hormonally active tumors should be removed, and hormonally inactive tumors are resected based on size, imaging phenotype, and interval growth 2
- Laparoscopic adrenalectomy has become the surgical procedure of choice for most benign functioning and nonfunctioning tumors of the adrenal gland 2
- Clinical policies are needed to improve DST completion and the management of adrenal adenomas, as approximately 7% of patients with adrenal tumors completed a DST 4