Use of desmopressin as an alternative to corticotropin-releasing hormone during inferior petrosal sinus sampling in a child with Cushing's disease.

Cushing's syndrome (CS) is rare in children. Information on bilateral inferior petrosal sinus sampling (BIPSS) in children with CS is limited. In the procedure CRH is always used to stimulate ACTH values. In addition, growth failure is the main complication of pediatric CS, mainly due to a profound GH suppression that persists for a few months after cure of the disease. Early treatment with recombinant GH after CS cure may partly reverse this phenomenon. We report herein a case of Cushing's disease (CD) in a 7-yr-old child, presenting with severe growth failure. No pituitary adenoma was shown on magnetic resonance imaging and a BIPSS using desmopressin allowed the identification of a central to peripheral (C/P) gradient; however transphenoidal surgery (TSS) did not cure the disease thus requiring the performance of bilateral adrenalectomy. After cure of the disease, a partial catch up of the growth delay occurred without any GH treatment. Our case reinforces the fact that BIPSS can be performed safely in very young children with CD. It also suggests for the first time that the use of desmopressin during the procedure gives the same information as CRH, as well as confirming the fact that the success of TSS is poor in very young children. Finally, it suggests that growth failure in children with CS can be partially reversed after surgical cure of the disease without any GH treatment and that the high IGF-I observed during corticosteroid replacement therapy is due to a state of IGF-I resistance.