What is the differential for this lesion?
Myxopapillary ependymoma, spinal schwannoma, intradural metastases (e.g. ependymoma) or spinal paraganglioma.
There is a well defined intradural ovoid lesion that is centered within the distal lumbosacral canal. Lesion fills the canal space from the L5-S2 levels. The lesion is confined to the canal without extension into the adjacent exit foramen. The lesion measures 5.5 x 1.5 x 2.2 cm in vertical, AP and transverse dimensions respectively. It is difficult to determine if the mass arises from a specific nerve root. The lesion has heterogeneous signal characteristics. The lesion predominately low signal on T2 weighted images with areas of moderate signal within. The lesion is isointense to CSF on T1 weighted images and enhances fairly homogeneously post contrast. On STIR weighted imaging the lesion is predominantly moderate signal intensity with areas of low signal within which likely represent blood products.