Clinical features associated with recurrence of tumours of the spinal cord and cauda equina

Study design: Retrospective review of consecutive cases of recurrent spinal cord and cauda equina tumours. Objectives: We sought to identify factors and conditions resulting in re-operation to treat recurrences of spinal cord and cauda equina tumours. Setting: Keio University Hospital, Tokyo, Japan. Methods: Re-operation was performed in 39 patients with spinal cord and cauda equina tumours. Times of operation, interval between operations, affected spinal level, tumour site on cross section, configurations among dumb-bell tumours, and pathologic diagnoses were analysed. Recurrence rates were defined in terms of the number of cases with re-operation due to tumour recurrence relative to the total number of surgical cases for the same period at our institution. Results: Recurrence rates were relatively high for intradural, extramedullary tumours and for tumours located anteriorly rather than laterally. Of patients with intradural, extramedullary plus extradural tumours who underwent initial surgery at our hospital, 75% (9/12) recurred; all tumours had dumb-bell-type configurations. The overall rate of re-operation due to tumour recurrence in 249 cases was 7.2% at our institution. By tumour types, 40% of malignant schwannomas recurred (2/5), as did 35.7% of neurofibromas (5/14), and 33.3% of ependymomas (6/18). Conclusion: Risk factors for tumour recurrence were anterior location, an intradural, extramedullary plus extradural site, extensive dumb-bell tumours, and pathologic diagnoses of neurofibroma, ependymoma, or malignant schwannoma.