Structured Evaluation of adRENal Tumors Discovered Incidentally - Prospectively Investigating the Testing Yield

Rationale: Standard diagnostic work-up for adrenal incidentalomas (AI) consists of periodical biochemical analysis and CT-scanning in case the initial work-up does not demonstrate the presence of hormonal hypersecretion or adrenocortical carcinoma (ACC),respectively. With respect to the diagnosis of ACC, the health benefits of this strategy are controversial for the following reasons: a. critical appraisal of literature has revealed a much lower ACC frequency of 1.9% than previously presumed; b. CT sensitivity and specificity are suboptimal; c. risk of unnecessary adrenalectomies; d. exposure to ionising radiation; e. risk of CT contrast reactions (nephropathy, allergic reaction); f. health care related and economical costs. The hypothesis to be tested is that incorporation of a single baseline urinary steroid profiling (USP) into the management algorithm of AI is more cost-effective than a strategy solely based on repeat CT-scanning. Objective: SERENDIPITY aims to improve the cost-effectiveness of the diagnostic strategy for AI by the application of a single baseline USP. In addition, we aim to examine the psychological impact for patients with AI being currently subjected to repeated laboratory tests and CT-scanning during several years. Study design: This is a prospective observational multicenter study. Study population: Patients are eligible if they meet the following inclusion criteria: adrenal mass \> 1 cm in diameter incidentally discovered during CT or MRI-scanning, performed for reasons other than an evaluation for adrenal disease and age 18 years or older. The exclusion criteria are: extra-adrenal malignancy (i.e. active or past medical history of malignancy, except for basal cell carcinoma), radiologic diagnosis of simple cyst or bilateral adrenal masses, allergy to radiocontrast, renal insufficiency (i.e. eGFR \< 30 ml/min/1.73m2), pregnancy or inability to understand written Dutch.