Intramedullary Spinal Cord Metastases: A 20-Year Institutional Experience with a Comprehensive Literature Review

OBJECTIVES: To review previous reports as well as our institutional experience to address the issues regarding patient management and also to assess the predisposing factors that might influence outcome and survival. METHODS: We undertook a 20-year (1989-2009) retrospective study of a series of eight patients diagnosed with intramedullary spinal cord metastases (ISCMs) in our institute. We further reviewed 293 cases of ISCMs reported in the English literature since 1960. Characteristics regarding the site of the primary cancer, location of ISCM, the presence of other metastases, presenting neurological symptoms/signs, duration of symptoms, and the time interval from diagnosis of the primary tumor to ISCM were pooled. We analyzed the different treatment approaches, the functional outcome, and the factors influencing survival. RESULTS: Lung and breast cancers appear to be the most frequent source of ISCM with cervical, thoracic, and lumbar spine being equally affected. Motor weakness predominates as the commonest symptom at presentation, followed by pain and sensory disturbance. At diagnosis, most patients with ISCM have a known primary cancer often associated with cerebral and other systemic metastases. Overall survival of ISCM is poor (median: 4 months from the time of diagnosis). Survival in surgical patients is 6 months, compared with 5 months in those conservatively managed. Clinical improvement was observed in more than one-half of those treated surgically, whereas neurological status was maintained in most patients treated conservatively. CONCLUSION: ISCM is an unusual site for metastasis. Regardless of the treatment, its prognosis is generally poor as its presence often signifies end-stage cancer. However, with early diagnosis and appropriate treatment, selected patients may benefit from improved neurological outcome and quality of life.