MRI of spinal cord radiation necrosis simulating recurrent cervical cord astrocytoma and syringomyelia

BACKGROUND Although primary intramedullary tumors of the spinal cord with syrinx formation are well documented, there have been no reports of extensive syrinx formation or cystic degeneration associated with radiation necrosis. METHODS We report a case of radiation necrosis and syrinx formation in a 49-year-old woman with a 5-year history of astrocytoma grade II of the cervical cord, who progressed to quadriparesis following surgery and radiation therapy. Magnetic resonance imaging (MRI) of the cervical and thoracic spine demonstrated enlargement of upper cervical cord (C1-C6) with diffuse increased signal and enhancing mass by gadolinium, as well as appearance of syrinx from T4-T10. RESULTS Autopsy findings indeed revealed a small, residual, infiltrating glioma in the upper cervical areas, but the diffuse parenchymal abnormality seen on MRI as prolonged T 2 characteristics on double-echo spin-echo sequence was revealed to be radiation necrosis. CONCLUSION What appeared to be a cystic cavity or syrinx at the thoracic level was also diagnosed as radiation necrosis with cyst formation on histologic examination.