Intracranial mature teratomas have good prognoses and are usually treated by total tumor resection. We report a rare case of a germinoma that occurred 11 years after total removal of a pineal mature teratoma. A 5-year-old boy presented with headache and nausea and was diagnosed with a pineal tumor and obstructive hydrocephalus on MRI. He underwent total removal of the lesion, which was pathologically diagnosed as a mature teratoma without any other germ cell tumor components. MR images after 11 years showed a newly developed pineal tumor, which was confirmed as a germinoma after neuroendoscopic biopsy. Chemoradiotherapy resulted in complete remission, without any symptoms. This case demonstrated possible late occurrence of germinoma even after total removal of a mature teratoma had been achieved. A long-term follow-up of 10 years or more should be planned for these patients.
Keywords: Germ cell tumor; Mature teratoma; Primordial germ cell; Pure germinoma.