A Case of Mediastinal Embryonal Carcinoma Successfully Treated by Integrative Therapy

Mediastinal embryonal carcinoma is rare, and the life prognosis of this disease is assumed to be relatively short. We encountered a case of mediastinal embryonal carcinoma for which we could perform radical surgical resection. The patient was male, aged 16 years, and acutely aware of back pain. Because the pain increased during the same year, he visited a local doctor, and an expanding neoplastic lesion was detected in the right thoracic wall by computed tomography (CT). Then he was referred to our institution. Magnetic resonance imaging (MRI) showed a dumbbell type tumor (Eden type 3) at the Th7/8 level. Malignant disease was suspected, so the authors planned and performed CT-guided biopsy. The result showed that this tumor pathologically corresponded to malignant peripheral nerve sheath tumor (MPNST). Therefore, chemotherapy was considered the main treatment. After 2 courses of chemotherapy, the tumor size decreased dramatically. The authors thought that radical resection is possible if there is no intrathoracic tumor dissemination as a result of a favorable response to chemotherapy. We thus perfomed surgical resection after we confirmed by a thoracoscopic exploratory thoracotomy that there was no intrathoracic tumor dissemination. Pathological findings were consistent with an embryonal carcinoma. Both the cutting ends of the thoracic wall and the epidural lateral sides of the excised lesion were negative for tumor cells. There is no image finding from the MRI and PET-CT suggesting metastasis or recurrence in the MRI and PET-CT 18 months after surgical resection. Therefore, the long-term vital prognosis can be expected in this patient.