De novo spinal teratoma after treatment of an intracranial germ cell tumor

The authors report an extremely rare case of de novo spinal teratoma after treatment for intracranial germ cell tumor. A 17-year-old male developed pain of bilateral lower extremities and urinary retention 18 months after complete remission of intracranial mixed germ cell tumor. Magnetic resonance imaging revealed a huge spinal tumor associated with spina bifida occulta. Total resection was performed, and histogenetical findings led to the diagnosis of a mature teratoma with normal p16 gene, whereas analysis of intracranial tumor showed p16 deletion. The spinal anomaly and genetic analysis strongly suggest that the spinal teratoma was a de novo tumor rather than a metastasis or dissemination of the original intracranial germ cell tumor.