Case report on an extremely rare type of ependymoma arising from the thigh.

ABSTRACT

INTRODUCTION: Ependymomas are neuroepithelial neoplasms of the central nervous system that arise from the precursor cells lining the ventricular system and the central canal of the spinal cord. Herein, we report a case of an extremely rare type of ependymoma arising from the thigh. Then, a literature review was performed. PRESENTATION OF CASE An 87-year-old female Japanese patient presented with a chief complaint of a mass on the medial aspect of her right thigh. Pathology revealed a grade 2 extra-neural ependymoma. PET-CT and brain MRI showed no neoplastic lesions in the central nervous system, and the tumor was localized only in the right thigh. The tumor was growing and was treated as a low-grade tumor with extensive resection and postoperative adjuvant radiotherapy. The patient has been alive for 3 years, without postoperative recurrence or complications. DISCUSSION: This case presents a rare extra-neural ependymoma of central nervous system origin arising in the thigh. The pathogenesis is unknown, but a search for neoplastic lesions in the cerebrospinal cord is warranted. Extra-neural ependymomas should be treated as low-grade tumors because they are more prone to recurrence and metastasis than ordinary ependymomas. CONCLUSION: We experienced an extremely rare extra-neural ependymoma arising in the thigh. A search for tumors in the central nervous system region of the cerebrospinal cord, previous literature, and clinical, imaging, and pathological findings should be consulted to determine a treatment strategy.