Intramedullary amputation neuromas associated with spinal ependymomas.

We report 5 spinal intramedullary masses containing combined ependymoma and traumatic neuroma. The ependymomas, grade II "cellular" types, were intermixed with or separate from wavy, vaguely fascicular tissue that contained multiple axons immunoreactive for neurofilament protein. The neuromas presumably arose from small perivascular nerve twigs that have been implicated in the pathogenesis of intramedullary neuromas in non-neoplastic spinal diseases. Pathologists should be aware of this distinctive intramedullary tissue that is not to be confused with a neoplasm.