Nelson's syndrome

Last reviewed 07/2021

This is a rare condition which may follow bilateral adrenalectomy for Cushing's syndrome. It results from the loss of feedback control of serum cortisol which leads to the development of an enlarging pituitary adenoma in 15-20% of cases.

Clinically, the patient presents with increased pigmentation associated with the very high levels of ACTH but not directly due to it.

Post-operative pituitary irradiation reduces the risk of this condition although adrenalectomy itself is now rarely performed.