[A case of mediastinum malignant teratoma which recurred as bone metastases seven years after a resection, and survived for a long-duration].

We performed median sternotomy, anterior mediastinum tumor resection+cardiac sac, and right pleural+superior vena cava partial excision in the anterior mediastinum, for which tumor markers were abnormal, after preoperative chemotherapy (PEB therapy)for a mediastinal malignant teratoma of 8×6 cm in a malignant germ cell tumor. The tumor markers became normal. We postoperatively performed a course of the same chemotherapy. In spite of the normal tumor markers, bone metastases recurred seven years later, and he underwent the ninth thoracic vertebra resection+spinal fusion. Five years have passed since surgery and he has survived without a recurrence. This seemed to be a rare case in which a part of the mediastinum malignant teratoma which did not produce a tumor marker had a recurrence.