Natural reduction in acute intratumoral hemorrhage of spinal schwannoma in the cauda equina

A 58-year-old woman presented with acute pain in her back and her left leg. Magnetic resonance imaging (MRI) revealed an intradural schwannoma with an intratumoral hemorrhage between the lower L4 vertebra and L5/S1 disk level. A follow-up MRI after one month revealed that the tumor had regressed from the middle of L5 to the L5/S1 disk level. The tumor was totally resected. There have been several reports of intratumoral hemorrhage of spinal schwannomas occurring at the cervical, thoracic, and conus levels; however, there has been only one previous report of it being seen at the L2-3 middle lumbar level and none at all at lower lumbar levels. This is the first report of an intratumoral hemorrhage of a schwannoma in the lower lumbar area. Furthermore, natural regression of an intratumoral hemorrhage of spinal schwannoma at lower lumbar levels has not previously been reported.