High accuracy of bilateral and simultaneous petrosal sinus sampling with desmopressin for the differential diagnosis of pediatric ACTH-dependent Cushing's syndrome

Purpose: To analyze the bilateral and simultaneous petrosal sinus sampling (BIPSS) in a subgroup of children and adolescents with ACTH-dependent Cushing's syndrome (ADCS) METHODS: Retrospective study in a tertiary reference center. From 1993 and 2017, 19 children and adolescents (PED) were submitted to the BIPSS, median age of 14 years (range 9-19 years), 53% were males, 18 had Cushing's disease (CD) and one had ectopic ACTH syndrome (EAS). All procedures were performed with 10 µg of intravenous desmopressin.

Results: The catheter positioning was successful in all cases. The central ACTH gradient was met in 17/19 cases. At baseline, central gradient occurred in 16/19 (84%) with gradient values of 7.2 ± 6.0. After stimulation, there was an increase in the center-periphery gradient values (33.6 ± 44.3). In one case, central gradient was defined only after stimulation. Two cases presented without a central gradient; one case of CD with a false-negative and one EAS case. Lateralization occurred in all cases with a central gradient. Confirmation of the tumor location presumed by the procedure with the surgical description occurred in 60% of the cases. The BIPSS in this PED subgroup of ADCS presented a sensitivity of 94.4% and specificity of 100%. There were no complications of the procedure.

Conclusion: In a series of children and adolescents with ADCS, BIPSS was safe and highly accurate in defining the central to peripheral ACTH gradient using desmopressin as secretagogue. Nevertheless, there was a limited value of the ACTH-gradient between the petrosal sinuses for the tumor location.