An unusual presentation of pediatric Cushing disease: recurrent corticotropinoma of the posterior pituitary lobe.

ABSTRACT

Cushing's syndrome (CS) is rare in childhood and adolescence and its diagnosis and work up are often challenging. We report the case of a 15-year-old girl with a recurrent corticotrophin (ACTH)-secreting adenoma, located in the posterior lobe of the pituitary gland. At the age of 11, she presented with classic CS symptoms; biochemical investigation was compatible with ACTH-dependent Cushing disease, although pituitary gland imaging did not show any tumor. Following transsphenoidal surgery (TSS), histopathological analysis identified an ACTH-secreting pituitary microadenoma arising from the posterior gland. The patient went into remission but 4 years later she presented with recurrent CS; this time, pituitary gland imaging showed a microadenoma located in the posterior lobe, which was resected after TSS. Posterior lobe pituitary adenomas are very rare and often hard to diagnose and treat; this is the first case of such a tumor causing recurrent Cushing's disease in a child.