[Mediastinal neuroblastoma: Unusual localization with late revelation]. / Neuroblastome médiastinal : localisation inhabituelle à révélation tardive.

Neuroblastoma (NB) is an embryonal tumor of the sympathetic nervous system. It represents the most common malignant extracerebral solid tumor, and the first solid tumor in children aged less than one year. Neuroblastoma is rare in adults. We report the case of a 21-year-old male patient. Diagnosis of neuroblastoma was confirmed by percutanous CT scanner biopsy. Radiological assessment of the extension concluded to a stage IV NB with multifocal bone disease. The patient received chemotherapy based on cisplatin-etoposide (6 cycles) and a mediastinal radiotherapy. The evolution was marked by the progression of bone metastasis and the emergence of a tissular process sheathing the left optic nerve and the terminal portion of the internal carotid artery. Second line chemotherapy was indicated. A thoracic localization of NB is rare. Treatment is not codified and the prognosis is variable.