Metastatic myxopapillary ependymoma treated with immunotherapy achieving durable response.

Myxopapillary ependymoma (MPE) is a rare glial tumour mainly located in the areas of the conus medullaris, cauda equina and filum terminale of the spinal cord. Ectopic MPE tends to behave more aggressively and distant metastases are often seen. Unfortunately, no standard treatment options are established as only small series of treated patients and a few reported cases are available in the literature. We report the case of a 25-year-old woman who was initially diagnosed with a metastatic MPE, with multiple bilateral lung metastases. She was treated with an investigational monoclonal antibody antiprogrammed cell death protein 1, called tislelizumab (BGB-A317), following surgical resection of the perisacral primary mass. The response was long-lasting and side effects nil. Immunotherapy is a treatment modality to be considered in patients with rare tumours.