Neurilemomas of the cauda equina presenting as prolapsed lumbar intervertebral disks

Neurilemomas of the cauda equina can present with a clinical syndrome indistinguishable from an acute prolapsed lumbar intervertebral disk. There is backache and sciatica, occasionally after trauma, and straight leg raising is usually limited with signs of L-5 or S-1 root compression. The only distinguishing clinical characteristic is that the pain is worse on recumbency and relieved by sitting or walking. There may be no plain x-ray changes for many years and the tumor is usually at the level of L-2 or L-3 vertebral body. Seven such cases are described in this report.