抄録
A 16-year-old male patient was diagnosed as having an intracranial germ cell tumor in the anterior third ventricle. Surgery revealed that the tumor was composed of embryonal carcinoma, endodermal sinus tumor, and teratomatous elements, such as cartilage, myogenic tissue, and keratinizing squamous epithelium. Alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) were elevated in the serum preoperatively and demonstrated also in the excised tumor tissue by the immunohistochemical method. After postoperative radiation therapy, the serum AFP and HCG returned to normal limits. About 1 year after the first operation, a recurrence of the tumor, with marked elevation of serum AFP, was detected. A second operation was performed, and the histological examination showed mostly endodermal sinus tumor with irradiation effect and teratomatous elements. The embryonal carcinoma portion had almost disappeared as a result of the earlier radiation therapy. Changes in the tumor composition correlated with changes in serum tumor markers. The patient is being followed closely.