Germinoma of the medulla oblongata--case report.

A 32-year-old female presented with medulla oblongata germinoma manifesting as numbness in the extremities. Computed tomography demonstrated a mass in the medulla oblongata expanding into the fourth ventricle. The tumor was partially removed. Immunohistochemical staining of the tumor specimen demonstrated large epithelioid cells positive for placental alkaline phosphatase, and syncytiotrophoblastic cells positive for beta subunit of human chorionic gonadotropin. Some epithelioid cells were also positive for cytokeratin. She received 44 Gy of irradiation to the posterior fossa and 20 Gy whole spinal irradiation. No signs of recurrence have occurred for 9 years. Patients with medulla oblongata germ cell tumor are comparatively older than those with other intracranial germ cell tumors and have two X chromosomes. All tumors were diagnosed as germinoma, and caused symptoms of involvement of the lower cranial nerves and the lower brain stem without pyramidal tract signs.