Intraoperative and pathological findings of intramedullary amputation neuroma associated with spinal ependymoma

Amputation neuromas typically arise in injured peripheral nerves; rarely, however, they arise in the spinal cord. We report a rare case of intramedullary amputation neuroma associated with ependymoma in the cervical spinal cord. A 73-year-old woman presented with a 5-year history of progressive gait disturbance. Neurological examination revealed complete motor deficit of her hands and legs. Magnetic resonance imaging of the cervical spine revealed an enhancing mass within the spinal cord at the C6/7 level. The patient underwent C5-C7 laminectomy surgery. During resection of the spinal tumor, we found a whitish string resembling an aberrant nerve root or schwannoma with adhesion to the tumor on the ventral side of the spinal cord. After resecting the tumor, the surgical specimen was cut and separated into a soft greyish tumor (spinal tumor) and the tough whitish string. Histopathological and immunohistochemical examination revealed the former was a spinal ependymoma and the latter was a neuroma. An intramedullary amputation neuroma associated with a spinal ependymoma is rare, and this is the first known case in which intraoprerative findings were clearly shown. Neurosurgeons should be aware that spinal ependymomas might coexist with neuromas.