Cyclical Cushing's syndrome first diagnosed after pituitary surgery: a trap for the unwary.

Three patients were studied after transsphenoidal microsurgery for Cushing's disease because their symptoms and signs were slow to settle and/or because they had variable endocrine results. All were established as having cyclical Cushing's syndrome, first diagnosed post-operatively. This may be a much more common finding than previously realized and emphasizes the need for detailed and ongoing endocrinological investigation after transsphenoidal surgery for Cushing's disease.