Isolated eccentric syrinx of the conus medullaris simulating a tumour.

There are many reasons for the formation of cavities in the spinal cord. A focal cavitation is distinguished from syringomyclia by the absence of an ependymal lining in the former as opposed to the latter. The authors report a case of an isolated eccentrically placed syringomyelia of the conus medullaris, which caused a cauda equina syndrome and resembled a tumour on MRI.