Extra-neural metastases of recurrent myxopapillary ependymoma: A patient case and literature review.

Background: Biologically and morphologically distinct from other ependymomas, myxopapillary ependymomas (MPEs) are rare, slow-growing glial tumors originating predominantly from the conus medullaris, cauda equina, or filum terminale. Gross total resection is the standard of care for primary MPE. Nevertheless, despite maximal resection, the risk of recurrence, usually within the neural axis, remains high. However, extra-neural metastases can also occur. Due to the rarity of the entity, there is a lack of consensus on the management of recurrences and extra-neural metastatic disease. We present a case report and literature review of this rare ependymal tumor.

Case description: We describe a case of a male patient with MPE who developed multiple recurrences, treated with numerous surgical resections, radiotherapy, and salvage chemotherapy before eventually developing extra-neural metastatic disease to lungs, abdomen, and lymph nodes 37 years after initial diagnosis. A biopsy of an axillary lymph node confirmed histomorphology comparable to the primary histology.

Conclusion: To our knowledge, there are <30 cases of extra-craniospinal metastatic MPE reported since 1955. Consequently, there is no major consensus on the treatment of extra-neural metastatic MPE. Case reports and series remain of utter importance to share experience and help customize management. From this angle, surgery, and radiotherapy are still used in the face of central nervous system recurrence and "limited" extra-neural spread, depending on the patterns of invasion. Chemotherapy has shown a modest effect so far; however, positive outcomes from targeted agents and immunotherapy (alone or combined) have been reported, which warrants further exploration.