Where is the abnormality?
There are in fact two, both intradural, extramedullary. The larger of the two is located just below the conus. The smaller is in the thecal cul de sac.
MRI demonstrates an ovoid lesion immediately below the conus, which is isointense to cord on T1 and somewhat hyperintense on T2, with small regions of signal drop out posteriorly. It enhances vividly following contrast.
A second smaller nodule with similar signal intensity is located in the thecal cul de sac immediately above a left sided small Tarlov cyst.