A case of successful treatment of a metastatic intramedullary tumor with an immune checkpoint inhibitor

<p>Introduction: Metastatic intramedullary spinal cord tumors have a poor prognosis, and chemotherapy is considered ineffective. We report a case of a patient who had a good outcome with an immune checkpoint inhibitor after resection of a metastatic intramedullary tumor.</p><p>Case Report: 74-year-old male underwent upper lobectomy for lung cancer. Seven months after surgery, he developed urinary retention and difficulty in walking. Contrast-enhanced MRI revealed an intradural extramedullary tumor with homogeneous internal contrast at C7~Th1 level, and an emergent tumor resection was performed. Intraoperative findings revealed that part of the tumor was firmly adhered to the spinal cord, so the adhered area was cauterized. Immediately after surgery, the patient's paraparesis improved and he was able to walk with a cane. The histopathological diagnosis was lung cancer metastasis, and postoperative MRI showed residual intramedullary lesions, which led to the diagnosis of metastatic intramedullary tumor. Since the tumor cells highly expressed PD-L1, treatment with an immune checkpoint inhibitor was started, and the spinal cord edema improved and the patient was able to maintain his ambulatory function.</p><p>Conclusion: Recently, the efficacy of immune checkpoint inhibitors for brain metastases of lung cancer with high PD-L1 expression was demonstrated. In this case, spinal cord edema improved and good neurological function was maintained, suggesting that immune checkpoint inhibitors may also be effective in metastatic intramedullary spinal cord tumors.</p>