[A case report of paraneoplastic Cushing's syndrome in young adults: a rare entity and real diagnostic challenge].

Paraneoplastic Cushing's syndrome is a rare cause of ACTH-dependent Cushing's syndrome, rarely observed in young adults, and often presents a challenge in determining its etiology. We report the case of a 16-year-old female patient presenting with a severe hypercortisolism, for which no underlying cause could initially be identified. Her clinical condition worsened, leading to emergency bilateral adrenalectomy as a life-saving measure. The underlying tumor pathology was diagnosed several months later on the basis of functional imaging. The patient underwent surgical excision, resulting in significant clinical improvement. This case highlights both a rare form of ACTH-dependent Cushing's syndrome and the very young age of onset, demonstrating the difficulty in establishing a precise etiological diagnosis, often requiring advanced imaging techniques.