From the Guidelines
Adrenal gland nodules should be evaluated with a focused history and physical examination, and a low threshold for multidisciplinary review 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.
Evaluation and Management
The evaluation of adrenal gland nodules should include a non-contrast CT as first-line imaging to distinguish benign lesions from those which require further radiologic investigation 1.
- Patients found to have an indeterminate incidental adrenal mass should undergo second-line imaging with either washout CT or chemical-shift MRI.
- Adrenal mass biopsy should not be performed routinely for the work-up of an adrenal incidentaloma.
- All patients with adrenal incidentalomas should be screened for autonomous cortisol secretion, with 1 mg dexamethasone suppression testing being the preferred screening test when clinically appropriate 1.
Hormone Screening
- Patients with adrenal incidentalomas and hypertension and/or hypokalemia should be screened for primary aldosteronism with an aldosterone-to-renin ratio.
- Adrenal vein sampling is recommended prior to offering adrenalectomy in patients with primary aldosteronism 1.
- Patients with adrenal incidentalomas that display >10 HU on non-contrast CT or who have signs/symptoms of catecholamine excess should be screened for pheochromocytoma with plasma or 24-hour urinary metanephrines.
Treatment
- Patients with unilateral cortisol-secreting adrenal masses and clinically apparent Cushing's syndrome should undergo unilateral adrenalectomy of the affected adrenal gland, with minimally-invasive surgery (MIS) being performed when feasible 1.
- Adrenalectomy should be performed for patients with unilateral aldosterone-secreting adrenal masses and pheochromocytomas, with MIS being performed when feasible.
- Minimally-invasive adrenalectomy can be offered to patients with suspected adrenocortical carcinomas that can be safely resected without rupturing the tumor capsule, while open adrenalectomy should be considered for patients with larger adrenocortical carcinomas or those presenting with locally advanced tumors, lymph node metastases or tumor thrombus in the renal vein/inferior vena cava 1.
From the Research
Adrenal Gland Nodules: Detection and Evaluation
- Adrenal nodules are detected with increasing frequency, and guidelines for their management have been produced by the National Institute of Health (NIH), American College of Radiology (ACR), and the American Association of Clinical Endocrinologists and American Association of Endocrine Surgeons (AACE/AAES) 2.
- Adrenal incidentalomas are adrenal mass lesions >1 cm in diameter serendipitously discovered by radiological examination, and they require structural assessment to distinguish common benign pathologies from the rare malignant ones, and biochemistry to exclude hypersecretion syndromes resulting from excess cortisol, aldosterone or catecholamines 3.
Diagnosis and Treatment
- The diagnosis of primary hyperaldosteronism requires correlating CT findings with endocrinologic studies, as significant diagnostic errors can occur if CT findings are not correlated with results of endocrinologic studies 4.
- Utilizing standardized macros that make specific recommendations for hormonal evaluation in patients with adrenal incidentalomas leads to improved adherence to clinical guidelines 5.
- Increasing size of adrenal nodules is associated with more severe hyper-cortisolism and less dexamethasone suppression, and these cases need further evaluation and possibly surgery because of increased risks of metabolic syndrome and cardiovascular mortality 6.
Characteristics of Adrenal Nodules
- Adrenal nodules can be unilateral or bilateral, and the mean maximum diameter of unilateral nodules measured on CT was larger on the right than on the left 6.
- The mean baseline serum cortisol level was significantly higher in patients with incidentalomas than in control subjects, and there were significant correlations between maximum nodule diameter on CT and serum cortisol levels after the dexamethasone suppression test and at baseline 6.