Schwannoma of the conus medullaris: a rare case

Abstract

Intradural schwannoma of the conus medullaris is a rare form of spinal neoplasm, which commonly occurs in the lumbar region. Conus medullaris level is unusual for schwannomas. A 49-year-old woman presented with chronic sciatica, mild bladder dysfunction, and paresthesia in the buttocks. Magnetic resonance imaging of the spine showed a mass lesion in the conus medullaris region with nerve compression. The tumor was completely resected and diagnosed histologically as schwannoma. The patient recovered after surgery. Clinical and radiologic features of this rare tumor are reviewed and are accompanied by literature findings.

Figure 1.. Magnetic resonance (MR) images of schwannoma of the conus medullaris in a 49-year-old woman with chronic low back pain and sciatica.

A, the sagittal T1-weighted MR image shows an intradural, isointense lesion of the conus medullaris. B, on the axial T1-weighted MR images, this lesion was heterogeneously enhanced with contrast. The spinal nerves are displaced laterally.

Figure 2.. Intraoperative photograph shows the tabulated, oval intradural mass in the conus medullaris.

Figure 3.. Postoperative T2-weighted MR images of the patient. No evidence of tumor is seen on both sagittal (A) and axial (B) MR images, suggesting that the tumor was completely resected.

Figure 4.. Morphology of the resected tumor.

A, observing under a microscope, the tumor shows cellular and hipocellular areas (HE ×100). B, plumped spindle-shaped cells with palisading nuclei can be seen (HE ×100). C, S-100 immunoreactivity is observed in tumor cells (S-100 ×200).