Clinical Features of Intradural Extramedullary Spinal Cord Metastases ？in Primary Lung Cancer

Background and objective Intradural extramedullary spinal cord metastases in lung cancer is rare, and it leads to severe neurological damage. The aim of this study is to identify the clinical features of intradural extramedullary spinal cord metastases in primary lung cancer patients. Methods The 8 cases of lung cancer with intradural extramedullary metastases, who were hospitalized in Peking Union Medical College Hospital (PUMCH) during May 2013 to May 2016, were enrolled in the retrospective study. Medical charts of the 8 patients were reviewed systematically. Results Intradural extramedullary spinal cord metastases was diagnosed in 7 cases with non-small cell lung cancer (NSCLC) and 1 case with small cell lung cancer (SCLC). Cauda equina syndrome was the most common clinical manifestation. Malignant cells in cerebrospinal fluid were positive in all the 5 cases (100%) who underwent lumbar puncture. Contrast-enhanced magnetic resonance imaging (MRI) of spine manifested as diffuse abnormal enhancement of pial lining of spinal cordin 3 cases, intradural extramedullary nodules in 4 cases, and both of them in 1 case. Neurological symptoms were improved or stable in 4 cases who underwent targeted therapy and/or radiotherapy. The median overall survival was 5.8 months. Conclusion Intradural extramedullary spinal cord metastases can be diagnosed with caution according to its neurological symptoms and contrast-enhanced MRI presentation.Targeted therapy and/or radiotherapy may be effective for symptoms control.