Intramedullary Spinal Cord Metastasis from Renal Cell Carcinoma: A Systematic Review of the Literature

Intramedullary spinal cord metastases from renal cell carcinomas (RCCs) are rare and can cause serious diagnostic and therapeutic dilemmas. The related reports are very few. This review was aimed to perform an analysis of all reported cases with intramedullary spinal cord metastases from RCCs. In January 2018, we performed a literature search in PubMed database using a combination of the keywords "intramedullary spinal cord metastasis" and "renal cell carcinoma". In addition, we present the clinical, neuroradiological, and histopathological findings in our patient with an intramedullary metastasis from a RCC. 17 cases were generated in our research. The mean interval from diagnosis of RCC to diagnosis of ISCM was 22 months. The median survival of surgically treated patients was 8.6 months and 8 months in patients who underwent radical surgery. Based on our review, RCCs can invade the medulla of the spinal cord several years after removal of the primary lesion. The prognosis of ISCMs from RCCs was poor. Retrograde passage of tumor cells into the spinal cord from the inferior vena cava via the epidural venous sinuses may have been the pathological mechanism for ISCM in our patient. Radical resection and radiation are effective ways of achieving recovery of neurologic function and improving quality of life. More reports are needed to enable exploration of the mechanisms of metastasis and the optimal forms of therapy.