Nelson's syndrome after bilateral adrenalectomy for Cushing's disease

Abstract

Background: Presentation and outcome of Nelson's syndrome after bilateral adrenalectomy is variable.

Methods: Clinical records of 39 patients who underwent bilateral adrenalectomy for primary or recurrent Cushing's disease during a 15-year period were analyzed for frequency and evolution of Nelson's syndrome.

Results: The study included 32 females and 7 males with a mean age of 31 years; 20 patients had a hypophysectomy as the initial procedure, and 19 had an adrenalectomy. Of the group, 17 patients received prophylactic radiation therapy to the pituitary gland. A total of 11 patients, none of whom had received prophylactic radiation therapy, developed Nelson's syndrome (determined by skin hyperpigmentation, elevated serum ACTH levels, and enlargement of a previous pituitary tumor or development of a new tumor in patients with no previous pituitary abnormality) over a mean follow-up period of 53 months. Treatment for Nelson's syndrome included valproic acid, radiation therapy, and hypophysectomy as monotherapy or combined therapy. Of the remaining 28 patients, 10 (7 without prophylactic radio therapy) developed skin hyperpigmentation and increased ACTH levels without a tumor.

Conclusions: Nelson's syndrome is a frequent complication after bilateral adrenalectomy in the absence of prophylactic radiotherapy (28%). The syndrome can be successfully controlled by medical treatment and or radiotherapy; patients rarely require hypophysectomy.