Case of the month: January 1998--43 year old male with radicular pain.

A 43-year-old male presented with progressively worsening right lower extremity pain. MRI of the spine showed a discrete intradural, extramedullary, homogeneously enhancing, sausage-shaped mass at L1-L2, noted intraoperatively to expand the filum terminale. Gross, histological, and electron microscopic findings were those of a paraganglioma. The case is used to discuss the differential diagnosis for sausage-shaped tumors of the filum terminale.