Intramedullary spinal cord metastases: a single-institution experience

Background Intramedullary spinal cord metastasis (ISCM) is the rarest type of CNS involvement of systemic malignant tumors. The aim of this retrospective study is to evaluate the clinical features, treatment and natural course of patients with ISCM in a single institution of Korea. Methods We reviewed the medical records of all patients diagnosed with secondary malignant neoplasms involving the spinal cord at the Asan Medical Center between January 1995 and August 2006. Patients were diagnosed with ISCM if they had pathologically established malignancies originating outside the central nervous system (CNS), neurologic symptoms suggestive of spinal cord dysfunction, and either abnormal spinal MRI findings suggestive of ISCM or surgical or postmortem confirmation of ISCM. We excluded patients in whom ISCM was suspected because of known cancer and myelopathy, but with normal neuroimaging results. Results All 12 ISCMs arised from breast cancer (six patients) and lung cancer (three small cell lung cancer, three non-small cell lung cancer). Eight lesions were in the thoracic cord, one in the cervical cord, and three in both. In 11 patients, brain metastasis were combined with the development of ISCM. Initial symptoms included various paresthesias, sensory loss, and leg weakness. The duration of symptoms before diagnosis ranged from 2 days to 8 months (median, 7 days). Despite radiotherapy, neurologic status usually deteriorated rapidly, within a period of days to weeks. Median survival after ISCM diagnosis was 3.9 months (range 0.8-18.4 months) for all patients (breast cancer 5.5 months vs. lung cancer 1.0 month). Conclusion Our findings indicate that ISCM is a very rare type of CNS involvement and represents a dismal finding of systemic malignancy. ISCM patients arising from breast cancer appeared to fare better than those with lung cancer.