Abnormally increased signal within the spinal cord ("intramedullary lesion") is a finding with manifold etiologies, including demyelinating processes such as multiple sclerosis, tumors such as glial neoplasms, hemangioblastomas, paragangliomas, lymphomas, or metastases, infectious processes including HIV vascular myelopathy, and herpes viruses, inflammatory processes such as sarcoidosis, as well as other benign etiologies including lipomas, cavernous malformations, dural arteriovenous fistulae, spinal cord infarctions, transverse myelitis, abscesses, and spinal cord contusions.
Intramedullary spinal tumors are more common in those with neurofibromatosis. Intramedullary tumors typically result in cord expansion and almost always demonstrate some degree of enhancement following contrast administration; neither of these imaging findings were present on multiple imaging studies. Glial neoplasms, such as ependymomas, typically extend over several vertebral segments of the cord and are associated with cystic change and enhancement; astrocytomas demonstrate similar findings and are often associated with leptomeningeal spread. Hemangioblastomas manifest with diffuse cord expansion with contrast-enhanced imaging typically demonstrating an intensely homogeneous enhancing tumor nodule.
Intramedullary spinal metastases are rare and usually arise from lung carcinoma (40-85% of cases), followed by breast carcinoma (11%), melanoma (5%), renal cell carcinoma (4%), colorectal carcinoma (3%), and lymphoma. Metastatic disease typically demonstrates enhancement and would not be expected to remain stable over an approximate five-month period of time.
Intramedullary spinal tumors medical expert witness specialties include neurosurgery, anesthesiology, neurology, orthopaedic spine surgery, oncology, and radiation oncology.