Primary yolk sac tumor within the lateral ventricle.

A 13-year-old girl presented with an exceedingly rare case of primary yolk sac tumor located within the lateral ventricle, manifesting as headache, nausea, and diplopia. Magnetic resonance imaging revealed a 4-cm-diameter solid enhanced mass within the left inferior horn of the lateral ventricle. The tumor was removed subtotally via left middle temporal corticotomy. The histological and immunohistochemical diagnosis was pure yolk sac tumor. The serum alpha-fetoprotein (AFP) level was elevated at 1957.2 ng/ml and the serum beta-human chorionic gonadotropin level was 4 mIU/ml after surgery. The patient underwent radiotherapy (whole brain, 30 Gy; tumor bed, 21 Gy; whole spinal axis, 30 Gy) and chemotherapy (ifosfamide, cisplatin, etoposide). After three treatment cycles, the serum AFP level had decreased to 4.5 ng/ml. However, the tumor recurred with cerebrospinal fluid dissemination after nine cycles of chemotherapy. She died 18 months after surgery. The possibility of germ cell tumor should be considered in pediatric patients with brain tumors occurring outside the pineal or suprasellar region.