Ectopic ACTH syndrome due to thymic carcinoid tumor in a girl.

An 8 year-old girl had a cushingoid appearance for six months. Hormone study showed extremely high serum levels of cortisol (> 60 micrograms/dl) and adrenocorticotropic hormone (930 pg/ml). Initial chest X-ray showed nothing unusual, but a technetium-99mm MIBI scan showed an accumulation lesion in the left upper chest cavity. Chest magnetic resonance imaging demonstrated that the mass was in the superior anterior mediastinum. She had complete removal of the tumor with partial thymectomy. The pathology revealed a thymic carcinoid tumor. Carcinoid tumors of the thymus are extremely rare in children and they usually present with Cushing's syndrome. To our knowledge, this is the youngest patient who has ever been reported with this disease.