Endocrine Abstracts

Background: Adrenal masses are detected in 5-7% of adults. The European guidelines on managing adrenal incidentalomas published in 2016¹ have standardised the management of these patients. However, evidence of the guidelines’ impact on clinical care is still lacking.

Methods: We conducted a retrospective, comprehensive review of clinical presentation, radiological characteristics, final diagnosis, and outcome of a large cohort of patients with adrenal masses referred to our tertiary centre (Queen Elizabeth Hospital Birmingham, UK) between 1998 and 2022. We performed a sub-analysis comparing the characteristics and outcomes before and after implementing the 2016 guidelines.

Results: We included 1397 patients (55.7% women; median age 60 years, [interquartile range, IQR, 49-70]). Incidental discovery was the most frequent mode of presentation (67.9%). Overall, 14.7% of patients had bilateral masses, and 32.8% had masses≥4 cm (median 2.9 cm, [IQR 1.9-4.7]). Unenhanced computed tomography (CT) Hounsfield Units (HU) were available for 763 patients; of these, 32.9% had heterogeneous tumours or HU>20. 44.3% of patients had hormonally inactive adrenal masses. After standardised workup, the most common diagnoses were adrenocortical adenoma (ACA, 56.0%), phaeochromocytoma (12.7%), adrenocortical carcinoma (10.6%), and metastases from an extra-adrenal malignancy (5.7%). Eventually, 65% of patients referred for indeterminate masses were diagnosed as having benign lesions, while 18% remained indeterminate. At multivariable regression analysis, the significant predictors in discriminating malignant from benign lesions were HU>20 or heterogeneous mass (odds ratio, OR, 28.40, 95%confidence interval, 95%CI [5.87-137.56]), followed by increased serum androgens (OR 27.67, 95%CI [4.05-189.00]), mass detection during cancer surveillance (OR 11.34, 95%CI [3.32-38.70]), size≥4 cm (OR 6.11, 95%CI [2.22-16.86]) and male sex (OR 3.06, 95%CI [1.12-8.34]). After implementing the guidelines, there was no significant difference comparing patients seen before (n=386) and after 2016 (n=990) in the use of additional imaging in the entire cohort or among patients with indeterminate radiological appearance (HU>20 or heterogeneous density or size≥4 cm). Nevertheless, the proportion of patients with non-functioning benign adrenal masses that underwent multiple follow-up visits significantly decreased from 89.6% to 70.2%, while the discharge rate after the initial workup increased from 4.4 to 25.3% (P <0.001).

Conclusion: From our extensive review of patients with adrenal masses including a high proportion of large and heterogenous lesions, ACAs remained the commonest aetiology. Implementing the European 2016 guidelines positively impacted clinical practice, reducing the number of follow-up visits, and increasing the discharge rate of benign, non-functioning masses.

Reference: 1. Fassnacht M, et al. Eur J Endocrinol 2016 175