Large mediastinal teratoma originating from the aortic adventitia.

Many mediastinal tumors do not cause local symptoms, so they are discovered incidentally upon thoracic imaging. We present the case of a patient who had a large, mature, cystic, mediastinal teratoma. The primary tumor arose from the ascending aortic adventitia and was in a highly unusual location-the medial mediastinum. The teratoma, which was diagnosed in our patient on thoracic computed tomography for follow-up evaluation of empyema, was resected completely. To our knowledge, such a teratoma, arising from the adventitia of the ascending aorta in the medial mediastinum, has not previously been reported in the English medical literature. We review diagnostic methods and therapeutic approaches to such mediastinal tumors. We conclude that surgical resection is the method of choice for treating these tumors, because it enables radical therapy and tissue diagnosis after extirpation.