Cushing's disease in childhood.

Cushing's disease is rare in childhood. There is an equal sex incidence, and it accounts for approximately 75% of pediatric causes of Cushing's syndrome. Predominant features are weight gain, growth failure, virilization, and headache. Following confirmation of the presence of inappropriate hypercortisolemia, the accurate differential diagnosis to establish the pituitary as the source of excessive ACTH secretion involves demonstration of > 50% suppression of circulating cortisol during high-dose dexamathasone administration and exaggeration of the cortisol response to corticotropin-releasing hormone (CRH). Imaging of the pituitary reveals a microadenoma in only a minority of cases, but inferior petrosal sinus sampling for ACTH can be of value in confirming the pituitary location of the tumor and possibly its lateralization. Primary therapy is transsphenoidal surgery, which can be supported by direct pituitary irradiation if hypercortisolemia persists. In experienced hands, the therapeutic outcome is good.