ABSTRACT

Spinal intradural-extramedullary lesions (SIELs) are a relatively rare group of tumors that arise from the inner surface of the dura mater, the outermost meningeal layer surrounding the spinal cord. Patients usually present with pain. If the mass is large, it can also lead to compressive myelopathy. Common types of spinal intradural-extramedullary lesions include schwannomas, meningiomas, myxopapillary ependymomas, spinal intradural hemangiomas, and seeding metastases. Magnetic resonance imaging (MRI) and computed tomography are the primary imaging modalities used to diagnose spinal intradural-extramedullary lesions. MRI is particularly useful for visualizing the soft tissues of the spine, including the spinal cord, nerve roots, and tumors. In addition to spinal intradural-extramedullary lesions, the intradural-extramedullary space can also harbor other pathologies, such as cauda equina lesions. Cauda equina is a bundle of nerve roots located at the bottom of the spinal cord. Lesions affecting the cauda equina can cause similar symptoms to spinal intradural-extramedullary lesions, making differential diagnosis challenging. This presentation will discuss the imaging features of spinal intradural-extramedullary lesions and the differential diagnosis of cauda equina enhancement, which is also a relatively frequent and important finding of this anatomical area.