Pituitary Cushing's disease without adenoma

Recent reports of patients with Cushing's disease who have been explored via the transsphenoidal route indicate that the great majority has pituitary adenomas. We report a patient with biochemically documented pituitary-based hypercortisolism who had a clinical and biochemical remission following hypophysectomy. Serial sections of the pituitary tissue removed showed hyperplasia of corticotroph cells but no adenoma. Hypophysectomy was complete as documented by serum levels of FSH, LH, TSH, prolactin, hGH and ACTH at the lower limits of the respective assays, with no response to appropriate stimuli. This case demonstrates that a minority of patients with Cushing's disease has corticotroph cell hyperplasia without a pituitary adenoma.