Adrenal nodules in patients with Cushing's disease: prevalence, clinical significance and follow-up.

Adrenal glands in Cushing's disease (CD) range from normal to showing diffuse enlargement in most cases. The finding of nodular lesions has been reported, but information about prevalence and evolution is described in few reports. Aim: To investigate the prevalence of nodular adrenal glands in patients with CD and assess its evolution after disease remission. Subjects and methods: We assessed 41 CD patients' abdominal computed tomography (CT) scans obtained during the active phase of the disease and evaluated the dynamics of ACTH and cortisol secretion. CT was repeated after disease remission in patients with adrenal nodules. Results: Fifteen of 41 patients had nodular and the remaining 26 had normal or enlarged adrenal glands. Patients with nodules were older (45.1 +/- 8.8 vs 36.9 +/- 12.7 yr; p=0.03) and had longer-standing disease (57.3 +/- 56.9 vs 32.9 +/- 29.1 months; p=0.05) than patients with normal/enlarged adrenal glands. ACTH (45.4 +/- 21.3 vs 70.5 +/- 39.1 pg/ml; p=0.04) and urinary free cortisol levels (606.1 +/- 512.3 vs 301.0 +/- 224.7 mu g/day, p=0.01) were significantly lower in patients with adrenal nodules while there were no differences between the groups in terms of dynamic tests results. Post-operative follow-up showed regression or shrinkage of the nodules in 8 out of 10 patients in disease remission. Conclusions: We found that adrenal nodular glands are a frequent finding in CD in particular in older patients and in those with a longer-standing disease. Nevertheless, a high percentage of nodules regression or shrinking was evidenced in our series after disease remission.