Preoperative diagnostic evaluation of children with Cushing's syndrome

Recent advances in biochemical and imaging studies have improved the diagnostic accuracy of Cushing's syndrome. To better define roles for these studies in children, the authors reviewed their experience with this rare group of patients. Fifteen children, aged 11 weeks to 17 years, were treated for noniatrogenic Cushing's syndrome over a 33-year period. All children presented with signs of hypercortisolism. Nineteen different diagnostic tests were used, reflecting changes in how these patients are evaluated. Pathological diagnoses were adrenal cortical carcinoma (3), primary adrenocortical nodular dysplasia (PAND) (2), and pituitary adenoma (10). Children with adrenal cortical carcinoma presented with an adrenal mass and at a younger age (mean, 22.3 months). Key diagnostic features of patients with PAND were a low plasma adrenocorticotrophin hormone (ACTH) and no suppression with high-dose dexamethasone. Children with a pituitary cause of Cushing's syndrome presented at an older age (mean, 15.7 years) and were diagnosed using a combination of high-dose dexamethasone testing, simultaneous inferior petrosal sinus sampling, and/or ovine corticotrophin-releasing hormone stimulation test. A strategy for the diagnosis of Cushing's syndrome in children is presented.