Surgical treatment of primary spinal tumors in the conus medullaris

Abstract

Objective: The objective of this study was to evaluate the characteristics and surgical outcome of the conus medullaris tumors.

Methods: We retrospectively reviewed 26 patients who underwent surgery for conus medullaris tumor from August 1986 to July 2007. We analyzed clinical manifestation, preoperative MRI findings, extent of surgical resection, histopathologic type, adjuvant therapy, and outcomes.

Results: There were ependymoma (13), hemangioblastoma (3), lipoma (3), astrocytoma (3), primitive neuroectodermal tumor (PNET) (2), mature teratoma (1), and capillary hemangioma (1) on histopathologic type. Leg pain was the most common symptom and was seen in 80.8% of patients. Pain or sensory change in the saddle area was seen in 50% of patients and 2 patients had severe pain in the perineum and genitalia. Gross total or complete tumor resection was obtained in 80.8% of patients. On surgical outcome, modified JOA score worsened in 26.9% of patients, improved in 34.6%, and remained stable in 38.5%. The mean VAS score was improved from 5.4 to 1.8 among 21 patients who had lower back pain and leg pain.

Conclusion: The surgical outcome of conus medullaris tumor mainly depends on preoperative neurological condition and pathological type. The surgical treatment of conus medullaris tumor needs understanding the anatomical and functional characteristics of conus meudllaris tumor for better outcome.

Keywords: Conus medullaris; Primary tumor.

Fig. 1

Pre- and Post-operative magnetic resonance image of lipoma at the conus medullaris (case 16). A : The lipoma at the conus medullaris was revealed with high signal density on T1 weighted MRI. B : The lipoma suppressed typically on the Fat suppression MRI. C : The tumor was removed gross totally on the post operative MRI.