Prevalence and characteristics of adrenal tumors in an unselected screening population Summary Background With the widespread use of advanced imaging technology, adrenal tumors are increasingly being identified. Aim: To investigate the prevalence and characteristics of adrenal tumors in an unselected screening population in China. Design: Transversal study. (ClinicalTrials.gov: NCT04682938) Adjustment: A health examination center in China. Patients: Adults undergoing annual screening were invited to undergo adrenal tumor screening using adrenal computed tomography. Measurements: Participants with adrenal tumors had additional evaluation of malignancy risk and adrenal function. Results: A total of 25,356 participants were examined , of whom 351 were found to have adrenal tumors, with a prevalence of 1.4%. Prevalence increased with age, from 0.2% in participants aged 18 to 25 years to 3.2% in those aged 65 years and older. 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. The proportions of nonfunctioning adenomas were equally high in various age groups (72.2%, 67.8%, and 72.2% in those younger than 46, 46 to 65, and ≥66 years, respectively). Limitation: Only 212 of 337 participants with an adrenocortical adenoma underwent endocrine testing. Conclusion: The prevalence of adrenal tumors in the general adult screening population is 1.4%, and the majority of these tumors are non-functioning regardless of the patient’s age. The secretion of cortisol and aldosterone are the main causes of functional adenomas. |
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The incidence of adrenal tumors has increased 10-fold in the last 2 decades, in parallel with the increasing number of abdominal computed tomography (CT) scans.
The observed increase in the incidence of adrenal tumors was mainly due to the more frequent discovery of smaller adrenal incidentalomas in older patients. However, because an abdominal CT scan is usually ordered to evaluate a medical problem, imaging bias is very likely to occur in any prevalence study that relies on the availability of imaging.
A cross-sectional study of more than 25,000 adults found that with increased screening, the prevalence of adrenal tumors in an unselected community population was 1.4%. Prevalence increased with age, from 0.2% in adults 18 to 25 years of age to 3.2% in adults over 65 years of age. However, approximately 70% of the tumors identified were non-functioning, meaning they did not produce additional hormones, regardless of the participant’s age. The findings are published in Annals of Internal Medicine .
Most adrenal tumors found incidentally are non-functioning regardless of the patient’s age.
The detection rate of adrenal incidentaloma , or a nodule found incidentally that does not cause clinical symptoms, has increased as screening techniques have improved and become more common. However, most of the published literature on the prevalence of adrenal incidentalomas consists of retrospective surveys based on radiographic diagnoses in a medical records system, which could underestimate or overestimate the prevalence.
Researchers from the First Affiliated Hospital of Chongqing Medical University, Chongqing, China, conducted a cross-sectional study of 25,356 participants who received annual health assessments between November 2020 and November 2021. The authors report that of the 25,356 participants, identified that 351 people had adrenal tumors.
Of these, 337 participants with adrenal tumors were diagnosed with an adrenocortical adenoma and 14 were diagnosed with another benign nodule. No participant was diagnosed with a malignant mass. The authors also report that of 212 participants who completed endocrine testing, 69.3% were diagnosed with non-functioning adenoma, 18.9% were diagnosed with cortisol autonomy, 11.8% were diagnosed with primary aldosteronism, and no participants were diagnosed with pheochromocytoma. .
An accompanying Mayo Clinic editorial highlights how this research provides important information about the prevalence of adrenal tumors and supports current recommendations for universal hormone testing in any patient with an incidentally discovered adrenal tumor. However, the author cautions that the study is limited by the lack of hormonal testing in 37% of participants, particularly because people who declined hormonal testing were older and more likely to have hypertension. As such, both mild autonomic cortisol secretion and primary aldosteronism might have been more common in this group.
