Neuroendocrine tumors (NET) of the thymus are rare, usually aggressive, and prone to metastatic lesion. Ectopic adrenocorticotropic hormone (ACTH) secretion in thymic NET (TNEN) is associated with poor prognosis. Most of TNET express somatostatin receptors, it allows the use of somatostatin receptor scintigraphy (SRS) and SPECT/CT or PET/CT with 68Ga-labeled peptides for diagnosis and staging of the disease. Surgery (macroscopic-complete resection) is the mainstay treatment for TNET. Now, there are no unequivocal data in adjuvant therapy and its effectiveness. We present a case report of the pediatric patient with well differentiated atypical ACTH-producing thymic carcinoid. This localization was verified by whole body somatostatin receptor scintigraphy with 111In-DTPA-octreotide (Octreoscan). The patient proceeded with the surgical treatment followed by remission of hypercorticism without adjuvant chemotherapy. Tumor recurrence with redevelopment of ACTH-ectopic syndrome was detected after 67 months of observation.