IMMATURE TERATOMA PRODUCING ALPHA-FETOPROTEIN WITHOUT COMPONENTS OF YOLK-SAC TUMOR IN THE PINEAL REGION

A case of pineal region tumor in a 9-year-old boy with a high serum al pha fetoprotein (AFP) level is reported. The serum levels of beta-huma n chorionic gonadotropin (HCG) and placental alkaline phosphatase (FLA P) were not elevated. The tumor was composed of radiologically differe nt components and was removed surgically, Postoperative radiation ther apy was performed and the serum level of AFP gradually declined to the normal range, The pathological diagnosis was immature teratoma, and n o elements of yolk sac tumor or embryonal carcinoma were found. In the immunohistochemical study, AFP was detected in the cytoplasm of gastr ointestinal-type epithelium and primitive neuroepithelial element. Thi s is considered a rare case of intracranial immature teratoma in which AFP was detected immunohistochemically in the columnar epithelium and immature neural tissue.