Subcutaneous Sacro Coccygeal Myxopapillary Ependymoma: A Case Report and a Comprehensive Review of the Literature Reappraising Its Current Diagnostic Approach and Management

Abstract

Sacrococcygeal myxopapillary ependymoma (MPE) is an uncommon type I glial tumor detected most frequently in the lumbosacral area of adolescents and children. It is usually presented as an intradural ependymal tumor that originates from the filum terminale and other locations within the ventricular system along the craniospinal axis. In rare cases, however, MPE may develop as a primary subcutaneous tumor in the sacrococcygeal area. Tumors can also appear as a dorsal sacrococcygeal growth or subcutaneous nodule. In this case report, we describe a rare case presenting as a subcutaneous sacrococcygeal mass in an elderly female that was subsequently resected and confirmed as subcutaneous MPE. The current standard treatment for MPE is maximal surgical resection with or without postoperative radiotherapy based on the locoregional extent and histological grading. However, there is limited evidence that radiotherapy for oligometastatic foci improves longevity or extends the time to recurrence. In addition to this case report, we provide a comprehensive review of similar cases and case series in the medical literature. Prospective studies evaluating the efficacy of resection and/or radiotherapy are required for improved management of extradural MPE.

Co-occurrence of subcutaneous myxopapillary ependymoma, dermal sinus tract, and filum terminale lipoma: a review of the pathobiology of caudal spinal cord development and spinal cord tethering. Illustrative case

“…10 Based on our literature review, there have been 43 reports of subcutaneous, extra-axial MPE since its first description in 1902. 1,[11][12][13][14][15] Subcutaneous MPEs are hypothesized to arise from heterotopic ependymal cell rests located in the dermis and subcutis. 13,[16][17][18] The caudal segment of the spinal cord, including the distal lumbar cord, conus medullaris, and FT, arises via the processes of canalization and retrogressive differentiation, both of which are less-organized processes than primary neurulation.…”

Myxopapillary Ependymoma Metastasis Mimicking Pulmonary Embolism: An Illustrative Case

“…5 Many studies demonstrate that adjuvant radiotherapy following resection is associated with increased progression-free survival (PFS). [6][7][8] However, other studies do not report significant differences in 5-year PFS, recurrence rate, or overall survival benefit with adjunctive radiotherapy or chemotherapy compared with surgical resection alone. 5,[7][8][9] In addition, MPEs rarely metastasize outside of the cerebrospinal axis, and pediatric patients show higher rates of central nervous system dissemination and extramedullary presentation than adults.…”

“…[6][7][8] However, other studies do not report significant differences in 5-year PFS, recurrence rate, or overall survival benefit with adjunctive radiotherapy or chemotherapy compared with surgical resection alone. 5,[7][8][9] In addition, MPEs rarely metastasize outside of the cerebrospinal axis, and pediatric patients show higher rates of central nervous system dissemination and extramedullary presentation than adults. 1,[10][11][12] A few published cases that show MPEs spread outside the neuroaxis into other organ systems, most commonly to the lymphatic system.…”