Neurinoma of the cauda equina misdiagnosed as prolapsed lumbar disk. Report of three cases.

The authors report three cases of neurinoma of the cauda equina initially misdiagnosed as prolapsed lumbar disk. Computed Tomography failed to reveal the tumour, while showing evidence of disk-degenerative patology and being thus misleading. Similar cases are reported in literature. After a thorough analysis of the causes of such an apparently gross error, it is concluded that the main source of pitfalls arises from neglecting those typical clinical features differentiating prolapsed disk from oncogenetic sciatica. When oncogenetic sciatica is suspected Computed Tomography is inappropriate and even misleading, while the elective investigation is Magnetic Resonance.