Mobile lumbar spine ependymoma: case report and review of literature.

Migrating intra-spinal lesions are quite rare, and are most of the reported cases are schwannomas. Several theories have been proposed to explain the changing location of an intra-spinal tumor. We present a very rare case of migrating lumbar intra-spinal intra-dural lesion at the conus level, the pathology of which was an ependymoma, and review the possible etiologies of such a unique occurrence in view of the reported literature. We hypothesize loose connection to the tissue of origin, likely the filum, as the cause in our case. We thus highlight the importance of repeated imaging and careful planning before surgical intervention of intra-spinal intra-dural lesions, to avoid complications and wrong level surgery, especially when the lesions are in the cauda-equina area.