Background: Mature teratomas are common tumors in the pediatric population. They can arise in the central nervous system and often require surgical resection. They are classified as non-germinomatous germ cell tumors and their recurrence are extremely rare. Case Presentation: We are reporting the case of a 6-year-old boy who was diagnosed with mature pineal teratoma after he presented with signs of acute hydrocephalus. Histopathology did not reveal any other germ cell tumor component. He underwent a complete resection of the mass, with no adjuvant chemotherapy. Nine years post-operatively, magnetic resonance imaging results showed recurrence of the pineal tumor as a germinoma. Chemotherapy and radiotherapy resulted in significant shrinkage of the mass and resolution of the clinical symptoms. Conclusion: This case illustrates the possibility of the late recurrence of a germinoma after the complete removal of a mature intracranial teratoma. It also raises the issue of whether mature teratomas should be treated with adjuvant therapy after surgical resection to prevent their recurrence as another germ cell tumor.

Keywords: Germinoma, mature teratoma, germ cell tumor, pineal teratoma, case report