There have been few reports of intraspinal teratomas. We have found only 44 cases in English and 3 cases in Japanese literature. A seven-year-old boy was admitted to the Ryukyu University Hospital with chief complaints of low back pain, limping, and limitation of forward flexion of his trunk. On examination, deep tendon reflex of his lower extremities was normal without pathological reflex. Muscle weakness was recognized only on his left flexor hallucis longus. No sensory and no vesico-rectal disturbance were found. Both straight leg raising tests were positive, and his pubic hair appeared already. Spinal tap showed xanthochromia, hypercellularity and increased protein content. Myelogram revealed complete block at the interspace between first and second lumbar spine. Removal of tumor at cauda equina connected with sacral cord was performed surgically after laminectomy. Histopathological diagnosis of this tumor was teratoma with germinoma, showing high liquor level of H. C. G. (Human Chorionic Gonadotropin). This case showed higher level of one of the three laboratory determinats (α-fetoprotein, H. C. G, and F. S. H.) for the diagnosis of this tumor, still after the surgical removal of the tumor. So, carefull follow up study is needed.
