Primary malignant lymphoma of the cauda equina.

A case report of paraplegia secondary to a malignant B-cell lymphoma primary in the cauda equina is presented. Initial diagnosis was suggested on cytocentrifuge preparations of cerebrospinal fluid with subsequent tissue confirmation following bilateral laminectomy (T12-L3). Histologically, the tumor was a diffuse "histiocytic" lymphoma by Rappaport's or large noncleaved FCC lymphoma by Lukes and Collins classification. Immunologic studies typed the tumor as a B-cell neoplasm with lambda light chains. Following an extensive evaluation of the patient, the lymphoma was found to be limited to the lower spinal cord. Although radiotherapy was initiated there was no improvement of her neurological symptoms, and CSF cytology remains positive for rare malignant cells 2 months after diagnosis. A complete reevaluation at 3 months after laminectomy was negative for lymphoma involvement of other sites.