A pediatric patient with Cushing syndrome caused by ectopic ACTH syndrome and concomitant pituitary incidentalomas

Ectopic ACTH syndrome is a rare but important cause of pediatric Cushing syndrome, for which management by a multidisciplinary team is required. Although diagnostic evaluation is similar to that in adults, the variation in epidemiology may sway investigations, leading to inappropriate and/or incomplete diagnostic interventions. We present a case of 15-year-old girl with symptoms of severe ACTH-dependent Cushing syndrome and two pituitary adenomas. The ectopic source of ACTH production was confirmed after petrosal venous sampling was performed. Diagnostics and perioperative management of a pulmonary carcinoid tumor producing ectopic ACTH is reviewed. In pediatric patients, as in adult patients, a pituitary lesion <6 mm on MRI is not sufficient confirmation of Cushing's disease, and appropriate diagnostic work-up should be performed to assess the source of the ACTH overproduction.