Complete remission of Nelson's syndrome after 1-year treatment with cabergoline

In this case report we demonstrated that treatment with the long-acting Da receptor agonist cabergoline for 1 year induced normalization of plasma ACT H levels and disappearance of the pituitary tumor in a patient with Nelson' s syndrome. A young man underwent bilateral adrenalectomy and subsequent pi tuitary irradiation for Gushing's disease after unsuccessful neurosurgical treatment. Thereafter, he was given cortisone acetate replacement at the do se of 62.5 mg a day. Fifteen months after pituitary irradiation, he develop ed Nelson's syndrome, having skin hyperpigmentation, high plasma ACTH level s (376 ng/l) and a pituitary microadenoma (5 mm) documented at magnetic res onance imaging (MRI) of the pituitary region. After 6 months of cabergoline treatment, given at the dose of 1 mg a week, plasma ACTH levels were signi ficantly decreased (from 376 to 113 ng/l) but they were not normalized. Cab ergoline dose was then increased up to 2 mg a week. Six months later plasma ACTH levels were normalized (22 ng/l) and MRI demonstrated the disappearan ce of the pituitary adenoma. In order to investigate on the direct effect p layed by cabergoline treatment on the remission of Nelson's syndrome, the t reatment was withdrawn. Plasma ACTH levels significantly increased (119 ng/ l) after 3 months of treatment withdrawal. At the last follow-up, during ca bergoline treatment at the dose of 2 mg/week plasma ACTH levels were normal ized (40.4 ng/l). This case demonstrated that cabergoline treatment is able to induce the remission of Nelson's syndrome and may be a valid therapeuti c alternative in this syndrome. (J. Endocrinol. Invest. 22: 860-865, 1999) (C) 1999, Editrice Kurtis.