Surgical management of a rare myxopapillary ependymoma of the gluteal region: A case report

Abstract

Background: 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. Case Description: 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. She underwent a biopsy at an outside institution, with histology revealing myxopapillary ependymoma. The patient was referred to our hospital and underwent an interdisciplinary neurosurgical and orthopedic oncology en bloc resection of the ependymoma, which intraoperatively appeared to originate from the coccygeal nerve. Conclusion: In the present report, the authors 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.

Pediatric Extraspinal Sacrococcygeal Ependymoma: Report of Two Cases and Literature Review

“…Ependymoma represents the third most frequent CNS tumor in childhood and is mainly localized in the posterior cranial fossa where spinal localization is more frequent among adults [ 7 , 8 ]. The brain tumor most frequently originates or metastasizes outside the CNS [ 3 , 4 , 5 ]. More than a century ago, Mallory et al first described the case of an ependymoma that developed in the subcutaneous tissue of the sacrococcygeal region [ 9 ].…”

“…Since then, only a few cases have been reported in literature with less than 50 reported cases occurring in childhood during the last 35 years ( Table 1 ) [ 4 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. They occur more frequently in the sacrococcygeal region, followed by the pelvic region, while cases of onset in the liver, lung, or mediastinum are rarer and mainly described in adulthood [ 3 , 5 ]. As in the cases we have described, the most frequent histological type among sacrococcygeal ependymomas, reflecting their spinal counterpart, is the myxopapillary (grade 2 WHO), which is characterized by tumor cells arranged in a papillary manner around vascularized myxoid stromal cores, strongly and diffusely positive for GFAP and S-100 on immunohistochemical analysis [ 37 ].…”

“…The clinical presentation varies according to the onset region: in their review of sacrococcygeal ependymomas, Lien and colleagues found an asymptomatic mass as the most frequent initial presentation (about 50% of cases), while rarer symptoms such as pain, tenesmus, constipation, or signs of neuropathy were encountered [ 5 ]. The cases we have described also presented with a mass without associated symptoms, and the initial presumptive diagnosis were epidermoid cyst and germ cell tumor, respectively.…”

“…The cases we have described also presented with a mass without associated symptoms, and the initial presumptive diagnosis were epidermoid cyst and germ cell tumor, respectively. In fact, given their localization and the propensity to drain which could suggest a diagnosis of pilonidal cyst or other benign tumors, misdiagnosis at onset is very common, occurring in virtually all cases described in the literature [ 5 , 28 , 34 , 44 ]. Thus, with any soft tissue lesion of the sacrococcygeal region, the differential diagnosis must include also ependymoma, in addition to sacrococcygeal teratoma, neurogenic tumor, soft tissue sarcoma, and metastatic carcinoma.…”

“…Among all pediatric brain and spinal tumors, ependymoma occasionally arises outside the CNS. Various localizations are described in the literature: the most common during childhood is the subcutaneous tissue of the sacrococcygeal region, whereas less frequently is the presacral region; rarer localizations can include the mediastinum, liver, or lung, described mainly in adulthood [ 3 , 4 , 5 ]. Here, we report two cases of ependymoma of the sacrococcygeal region treated at our institution, with a review of the literature regarding this rare tumor in children.…”