SURG-30. SURGICAL MANAGEMENT OF A RARE SACROCOCCYGEAL MYXOPAPILLARY EPENDYMOMA OF THE GLUTEAL REGION: CASE ILLUSTRATION AND SYSTEMATIC LITERATURE REVIEW

Abstract

Abstract Ependymomas are rare tumors originating from neuroepithelial cells lining the wall of the ventricles or central canal of the spinal cord. While these tumors mainly occur within the central nervous system (CNS), there are occasional reports in children and young adult patients with a primary tumor occurrence outside of the CNS. Ependymomas of the sacrococcygeal region have been infrequently described in the literature with no standard of care established. We present a case report and review of the literature regarding this rare entity. A 24-year-old woman presented with right gluteal pain worsened by sitting and a palpable soft tissue mass of the sacrococcygeal region. Magnetic resonance imaging revealed a 3.7 cm cystic mass centered in the right gluteal region. Histology revealed myxopapillary ependymoma. The patient underwent an interdisciplinary neurosurgical and orthopedic oncology en bloc resection of the ependymoma, which intraoperatively appeared to originate from the coccygeal nerve. Through our systematic literature review, we identified 38 studies describing 78 unique cases of myxopapillary ependymoma occurring in the sacrococcygeal region without extension into the CNS. The exact presentation of sacrococcygeal ependymomas is variable. Given their location and propensity for drainage, they are frequently misdiagnosed as pilonidal cyst. Recurrence occured in 16.7% of cases described, typically within 20 years. Rate of metastasis was 20%. The primary means of management for sacrococcygeal myxopapillary ependymoma is complete surgical resection including excision of the neighboring sacrum or coccyx, when involved. Ultimately, we demonstrate that a myxopapillary ependymoma may present as an isolated gluteal mass attached to the coccygeal nerve, without frank CNS involvement. Furthermore, an interdisciplinary approach to surgical resection of this lesion appears to represent an effective treatment modality.