Is unilateral adrenalectomy an alternative treatment for ACTH-independent macronodular adrenal hyperplasia?: Long-term follow-up of four cases.

Objective: ACTH-independent macronodular adrenal hyperplasia is a rare cause of Cushing's syndrome. Bilateral adrenalectomy is considered the treatment of choice, but the patient is obliged to receive lifetime steroid replacement therapy and is susceptible to adrenal insufficiency crisis. New therapeutic alternatives are being proposed as new etiopathological features of the disease are known. Unilateral adrenalectomy of the largest gland can be a safe and effective alternative, but only short-term follow-up is reported in the literature. We present four consecutive patients with ACTH-independent macronodular hyperplasia and long-term remission of Cushing's syndrome after unilateral adrenalectomy.

Subjects: Four consecutive patients (two males and two females, mean age 50.3 years) with Cushing's syndrome due to ACTH-independent macronodular adrenal hyperplasia underwent unilateral adrenalectomy of the largest gland.

Results: The weight of the resected glands ranged from 26.8 to 210 g. Two patients suffered transient post-surgical adrenal insufficiency and had steroid replacement therapy for 60 and 14 months respectively. After a mean follow-up of 78.8 months (range 30-137 months) all the patients persist without any evidence of Cushing's syndrome. Urinary free cortisol and serum cortisol, after the adrenal insufficiency stage, have always stayed within their normal ranges, but cortisol circadian rhythm and suppressibility after dexamethasone have never normalized. No further enlargement of the contralateral gland has been documented 62 to 126 months after surgery in three of the four patients.

Conclusions: Unilateral adrenalectomy can be an effective and safe alternative treatment for ACTH-independent macronodular adrenal hyperplasia, and can achieve long-term remission of Cushing's syndrome.