Prevalence and Characteristics of Adrenal Tumors in an Unselected Screening Population : A Cross-Sectional Study.

<bold>Background: </bold>With the widespread use of advanced imaging technology, adrenal tumors are increasingly being identified.<bold>Objective: </bold>To investigate the prevalence and characteristics of adrenal tumors in an unselected screening population in China.<bold>Design: </bold>Cross-sectional study. (ClinicalTrials.gov: NCT04682938).<bold>Setting: </bold>A health examination center in China.<bold>Patients: </bold>Adults having an annual checkup were invited to be screened for adrenal tumors by adrenal computed tomography.<bold>Measurements: </bold>The participants with adrenal tumors had further evaluation for malignancy risk and adrenal function.<bold>Results: </bold>A total of 25 356 participants were screened, 351 of whom were found to have adrenal tumors, for a prevalence of 1.4%. The prevalence increased with age, from 0.2% in participants aged 18 to 25 years to 3.2% in those older than 65 years. Among 351 participants with adrenal tumors, 337 were diagnosed with an adrenocortical adenoma, 14 with another benign nodule, and none with a malignant mass. In 212 participants with an adenoma who completed endocrine testing, 69.3% were diagnosed with a nonfunctioning adenoma, 18.9% with cortisol autonomy, 11.8% with primary aldosteronism, and none with pheochromocytoma. Proportions of nonfunctioning adenomas were similarly high in various age groups (72.2%, 67.8%, and 72.2% in those aged <46, 46 to 65, and ≥66 years, respectively).<bold>Limitation: </bold>Only 212 of 337 participants with an adrenocortical adenoma had endocrine testing.<bold>Conclusion: </bold>The prevalence of adrenal tumors in the general adult screening population is 1.4%, and most of these tumors are nonfunctioning regardless of patient age. Cortisol and aldosterone secretion are the main causes of functional adenomas.<bold>Primary Funding Source: </bold>National Key Research and Development Program of China and National Natural Science Foundation of China. [ABSTRACT FROM AUTHOR]