Incidental adrenal masses are common and require a multidisciplinary approach to evaluation and management that includes family physicians, urologists, endocrinologists, and radiologists. The purpose of this guideline is to provide an updated approach to the diagnosis, management, and follow-up of adrenal incidentalomas, with a special focus on the areas of discrepancy/controversy existing among the published guidelines from other associations.
This guideline was developed by the Canadian Urological Association (CUA) through a working group comprised of urologists, endocrinologists, and radiologists and subsequently endorsed by the American Urological Association (AUA). A systematic review utilizing the GRADE approach served as the basis for evidence-based recommendations with consensus statements provided in the absence of evidence. For each guideline statement, the strength of recommendation was reported as weak or strong, and the quality of evidence was evaluated as low, medium, or high.
The CUA working group provided evidence- and consensus-based recommendations based on an updated systematic review and subject matter expertise. Important updates on evidence-based radiological evaluation and hormonal testing are included in the recommendations. This guideline clarifies which patients may benefit from surgery and highlights where short term surveillance is appropriate.
Incidentally detected adrenal masses require a comprehensive assessment of hormonal function and oncologic risk. This guideline provides a contemporary approach to the appropriate clinical, radiographic, and endocrine assessments required for the evaluation, management, and follow-up of patients with such lesions.

OBJECTIVE: Adrenal incidentalomas are being discovered with increasing frequency, and their discovery poses a challenge to clinicians. Despite the 2002 National Institutes of Health consensus statement, there are still discrepancies in the most recent guidelines from organizations representing endocrinology, endocrine surgery, urology and radiology. We review recent guidelines across the specialties involved in diagnosing and treating adrenal incidentalomas, and discuss points of agreement as well as controversy among guidelines.
METHODS: PubMed®, Scopus®, Embase™ and Web of Science™ databases were searched systematically in November 2019 in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement to identify the most recently updated committee produced clinical guidelines in each of the 4 specialties. Five articles met the inclusion criteria.
RESULTS: There is little debate among the reviewed guidelines as to the initial evaluation of an adrenal incidentaloma. All patients with a newly discovered adrenal incidentaloma should receive an unenhanced computerized tomogram and hormone screen. The most significant points of divergence among the guidelines regard reimaging an initially benign appearing mass, repeat hormone testing and management of an adrenal incidentaloma that is not easily characterized as benign or malignant on computerized tomography. The guidelines range from actively recommending against any repeat imaging and hormone screening to recommending a repeat scan as early as in 3 to 6 months and annual hormonal screening for several years.
CONCLUSIONS: After reviewing the guidelines and the evidence used to support them we posit that best practices lie at their convergence and have presented our management recommendations on how to navigate the guidelines when they are discrepant.

BACKGROUND: Approximately 5% of all abdominal computed tomography (CT) and magnetic resonance imaging (MRI) scans reveal an adrenal incidentaloma. Although most adrenal incidentalomas are benign non-functioning adenomas, lesions may be hormonally active and/or malignant. The aim of this study was to determine adherence to recommended international guidelines and potential influencing factors when an adrenal incidentaloma is identified in routine clinical practice.
METHODS: A retrospective study was performed of all CT and MRI reports from December 2009 to December 2011 using a key phrase search to identify patients with an incidental adrenal lesion.
RESULTS: A total of 125 patients with incidental adrenal lesions were identified, of which 74 patients were considered appropriate for further endocrine/radiological workup. Of the 74 patients, only 19 (26%) were initially referred to the endocrine service for investigation; 21/74 (28%) had complete biochemical workup and 24/74 (32%) had imaging follow-up arranged. The reporting radiologist provided advice for follow-up in 31/74 (42%), and action was more likely to be taken when this recommendation was given. Follow-up of the patients who had not received investigation was attempted resulting in assessment of a further 23 patients. Of the 44 patients who have undergone full assessment, four patients were found to have clinically significant lesions (one each of: Cushing\'s syndrome, phaeochromocytoma, Conn\'s syndrome and plasmacytoma).
CONCLUSIONS: This study suggests that the majority of adrenal incidentalomas may not be investigated according to current international guidelines. The recommendations by the reporting radiologist appear to influence whether a patient is referred for further investigation.

OBJECTIVE: To determine the clinical outcomes and follow-up imaging characteristics for incidentally discovered adrenal nodules at a large metropolitan health care center, as well as compliance with National Institutes of Health guidelines for the evaluation of these lesions.
METHODS: Between October 2003 and June 2005, computed tomographic (CT) scanning performed at Harvard Vanguard Medical Associates detected 165 adrenal nodules (incidentalomas) in 129 patients without extra-adrenal malignant lesions or evidence of adrenal hyperfunction. Nodule characteristics, including size at baseline, change in size at follow-up, CT attenuation values, biochemical data, and clinical outcomes, were analyzed.
RESULTS: Of the 165 adrenal incidentalomas, 96% were smaller than 4 cm. When attenuation values were determined, 65% were low (<10 Housfield units). Ninety-eight patients (76%) with 142 nodules (86% of all incidentalomas) had at least 1 follow-up CT scan. Of these 142 lesions, 20 (14%) changed significantly in size (grew or became smaller by 0.5 cm or more). Growth was detected within 12 months in 5 of the 7 lesions (71%) that grew. For 95% of patients, the adrenal nodule did not necessitate intervention, including change in medication or surgical treatment. Biochemical studies for adrenal hyperfunction were done in 39 of the overall 129 patients (30%), but in only 20 of 109 patients (18%) not seen by endocrinologists.
CONCLUSIONS: Most adrenal incidentalomas are benign, nonfunctional tumors. Growth typically occurs within 12 months after detection. Despite the 2002 National Institutes of Health guidelines, 82% of patients at our medical center with adrenal nodules who were not seen by endocrinologists did not have hormonal testing. More physician education about the evaluation of incidentalomas should be provided, and prospective studies to establish the appropriate duration of follow-up should be conducted.