A 13-year-old girl presented acutely with an episode of headache and signs of elevated intracranial pressure from a pineal gland tumor causing obstructive hydrocephalus. After an endoscopic third ventriculostomy and pineal gland biopsy, she was diagnosed with pineoblastoma. She was treated with surgical resection, craniospinal radiotherapy, and subsequent chemotherapy. Brain MRIs were performed every 3 months after surgery and remained stable with no new lesions or signs of residual tumor. However, a follow-up brain MRI performed 6 months after chemotherapy showed some small white matter nonenhancing lesions in supratentorial subcortical areas and within the cord at C7. She had no neurologic symptoms at that time and the white matter lesions improved over the next 3 months.