EARLY DIAGNOSIS OF NELSONS SYNDROME

Nelson's syndrome is a specific form of Gushing's disease treated by b ilateral adrenalectomy, presenting with a deep hyperpigmentation cause d by a pituitary adenoma (corticotropinoma). These ACTH-secreting tumo rs are frequently aggressive, so early diagnosis is of prime importanc e. We have studied 33 patients with Nelson's syndrome, 28 women and 5 men, aged 14-56 yr at the time of adrenalectomy and 16-58 yr at the ti me of Nelson's syndrome diagnosis (observed for 5-32 yr). Methods of e xamination included simultaneous adrenocorticotropic hormone (ACTH) an d cortisol measurements during routine hydrocortisone replacement ther apy, computed tomography (CT), pituitary magnetic resonance imaging (M RI), and visual field examination. The results obtained in a group of six patients diagnosed in the last 3 yr were compared with those obtai ned in a group of 27 patients examined before 1992. High plasma ACTH l evels accompanied by normal serum cortisol concentration were characte ristic for a late stage of the disease. Absolute temporal scotomas wer e an early finding. MRI, especially with the gadolinium enhancement, w as superior to CT in demonstrating pituitary microadenomas in Nelson's syndrome. Thus, MRI diagnosis allowed for an early neurosurgical trea tment of the patients with Nelson's tumors.