Prognostic factors in the treatment of the intradural extramedullary tumors:: a study of 44 cases

Between 1993 and 1999, 44 patients submitted to resection of an expansible intradural extramedullary lesion who filled protocol requirements of appropriate follow up were studied. Patients were constituted by 43.2% female and 56.8% male. The mean age was 32.9 years old. Lesion most common location was at the thoracic spine, with 45.5% of the cases, followed by the lumbar level with 18.2%. Tumor extension varied from 1 to 7 vertebral segments, with an average of 2.5 levels. Schwannoma, with 65,9% of the cases, was the most frequent lesion, followed by meningioma with 20.5%. There were 2 cases of neurofibroma and 1 case of paraganglioma, neuroenteric cyst, metastasis and malignant schwannoma. The evolution was of improvement in 56.8%, stability in 31.8% and of worsening in 11.4%. There was no mortality related to the surgical procedure. All cases of worsening had total resection and they had lesions located in the thoracic segment. Total resection is the ideal modality of surgical treatment. However, at the thoracic level, where the peculiarities of spine irrigation prevail, surgical morbidade may be higher (p = 0.014).