[en] We report 2 cases of thoracic neural crest tumors complicating the course in patients with Beckwith-Wiedemann syndrome (BWS). In the first patient, a thoracic neuroblastoma was fortuitously discovered at age 3 months on a chest film prior to a partial glossectomy. In the follow-up left nephroblastoma and a right kidney simple cyst appeared. In the second patient, a thoracic tumor which proved to be a mature ganglioneuroma was discovered at age 4 years on a follow-up spinal radiograph. Although less frequent than nephroblastoma and/or adrenal tumors, the occurrence of thoracic neuroblastoma in BWS suggests that periodic chest radiograph and assays of HVA, VMA and Dopamine should be included in the follow-up protocol. (orig.)