Surgical versus conservative management for subclinical Cushing syndrome in adrenal incidentalomas: a prospective randomized study.

OBJECTIVE: To compare the clinical outcome of patients with subclinical Cushing syndrome (SCS) due to an adrenal incidentaloma (the autonomous hypersecretion of a small amount of cortisol, which is not enough to cause clinically-evident disease) who underwent surgery or were managed conservatively.

SUMMARY BACKGROUND DATA: The most appropriate management of SCS patients is controversial, either adrenalectomy or close follow-up being recommended for their treatment.

METHODS: Over a 15-year period, 45 SCS patients were randomly selected to undergo surgery (n = 23) or conservative management (n = 22). All surgical procedures were laparoscopic adrenalectomies performed by the same surgeon. All patients were followed up (mean, 7.7 years; range, 2-17 years) clinically by 2 experienced endocrinologists 6 and 12 months after surgery and then yearly, or yearly after joining the trial, particularly monitoring diabetes mellitus (DM), arterial hypertension, hyperlipidemia, obesity, and osteoporosis. The study end point was the clinical outcome of SCS patients who underwent adrenalectomy versus those managed conservatively.

RESULTS: All 23 patients in the surgical arm had elective surgery. Another 3 patients randomly assigned to conservative management crossed over to the surgical group due to an increasing adrenal mass >3.5 cm. In the surgical group, DM normalized or improved in 62.5% of patients (5 of 8), hypertension in 67% (12 of 18), hyperlipidemia in 37.5% (3 of 8), and obesity in 50% (3 of 6). No changes in bone parameters were seen after surgery in SCS patients with osteoporosis. On the other hand, some worsening of DM, hypertension, and hyperlipidemia was noted in conservatively-managed patients.

CONCLUSIONS: Based on the results of this study, laparoscopic adrenalectomy performed by skilled surgeons appears more beneficial than conservative management for SCS patients complying with our selection criteria. This trial is registered with Australian Clinical Trials Registry number, ANZCTR12608000567325.