Mature spinal teratoma associated with thickened filum terminale

A 30-year-old man presented with an intradural spinal teratoma with thickened filum terminale manifesting as urinary and sexual disturbances, and low back pain persisting for 4 years. Spinal magnetic resonance imaging revealed thickened filum terminale containing a heterogeneously enhanced intradural lesion extending from the L-3 to L-4 levels and in contact with the conus medullaris. The filum terminale was incised and the tumor was totally resected. The histological diagnosis was mature teratoma consisting of three germ cell layers. The patient's complaints had completely resolved 6 months later.