Giant invasive schwannoma of cauda equina with minimal neurologic deficit: a case report and literature review.

A 53-year-old man presented with a history of slight weakness in the right lower limb. Giant invasive cauda equina schwannoma was diagnosed according to the criteria of Sridhar et al. Schwannomas are usually benign and common tumors arising from nerve sheath cells, particularly from sensory nerves. Giant invasive schwannomas, however, are rare, and most of patients with them present with severe neurologic deficits independent of daily activity, although in the case presented here, in spite of the large size of the tumor causing pedicle erosion, expansive destruction of the vertebral body and widening of the neural foramina, there were only minimal neurologic deficits. We have therefore decided to report this case, with a review of the relevant English literature emphasizing clinical presentations, plain film images and magnetic resonance image findings of giant invasive cauda equina schwannoma for early diagnosis and differential diagnosis.