High prevalence of adrenal imaging abnormalities in Cushing’s disease

Introduction: Cushing’s disease (CD) is the most common cause of endogenous Cushing’s syndrome. Adrenocorticotropic hormone (ACTH) has trophic and mitogenic effects on the adrenal cortex that may cause diffuse adrenal enlargement and nodular lesions. Aim: To evaluate the prevalence of adrenal structural abnormalities in patients with CD. Methods: Retrospective cohort study. We conducted a computerized search in our medical centers databases for the diagnosis of CD recorded between the years 1995–2024. Out of 124 patients with ACTH dependent Cushing’s syndrome, we identified 68 patients with CD who underwent adrenal imaging. We analyzed the clinical, biochemical, and imaging data. Results: Our cohort included 68 patients (51 females, 75.0%; mean age at the time of adrenal imaging, 44.6 ± 14.9 years). Sixteen (23.5%) patients had an adrenal nodule ≥10 mm (median size, 27.5 mm, IQR 14.3–38.3), and 19 others (27.9%) had adrenal hyperplasia or nodules <10 mm. The prevalence of adrenal nodules increased with age from 16.7% in patients aged 26–35 years to 26.3% in those aged above 55. Patients with adrenal nodules were older compared to those with normal adrenal glands (mean age, 49.0 ± 12.4 vs 39.1 ± 14.9 years; p = 0.03), and had lower ACTH level (0.7 x ULN, IQR 0.5–1.2, vs 1.2 x ULN, IQR 0.9–1.8, p = 0.02). Conclusions: We identified abnormal adrenal imaging in 51.5% of patients with CD. The prevalence of adrenal nodules in our study was 10-fold higher than in the normal population, for all age groups. This suggests that chronic ACTH secretion in CD is associated with adrenal nodules appearance.