Unexpected myxopapillary ependymoma within a filum terminale tethering the spinal cord

Filum Terminale Ependymoma in an Infant with Meningocele

This report describes a case of an ependymoma found in the setting of tethered cord syndrome. We present a 3-month-old girl with prenatal diagnosis of lumbar meningocele who later underwent tethered cord release. After birth, she was neurologically intact and only found to have a skin-covered meningocele. An MRI was obtained and significant for low-lying conus terminating at L5, a focal syrinx, and Chiari II malformation. She underwent an elective meningocele repair and resection of thickened filum for tethered cord release at 3 months of age. Unexpectedly, microscopic evaluation of the filum was consistent with a small focus of ependymoma in addition to the filum tissue. Previous case reports have suggested a link between thickened filum in the setting of spinal dysraphism and myxopapillary ependymoma, but to our knowledge, this is the first report of ependymoma in the setting of tethered cord syndrome.

Myxopapillary ependymoma in children: a study of 11 cases and a comparison with the adult experience

BACKGROUND

Myxopapillary ependymomas (MEPN) are uncommon tumors of the central nervous system, mainly occurring within the conus medullaris-filum terminale. MEPNs can also present in the skin and underlying soft tissues of the sacrococcygeal region. The incidence of extramedullary MEPNs in children is unclear.

PROCEDURE

We retrospectively reviewed our institutional files for MEPN cases between the years 1990-2012. A total of 11 pediatric and 38 adult cases were identified and compared to determine differences between these two distinct age groups.

RESULTS

There were 40 (82%) tumors arising in the spine and nine (18%) in extramedullary sites. Pathologic examination revealed that extramedullary and spinal MEPNs were indistinguishable morphologically and immunophenotypically. Among the 11 children with MEPNs, seven had tumors presenting in extramedullary sites whereas only two adults (5%) had extramedullary tumors; this difference was highly significant (P < 0.0001). The lumbosacral portion of the spinal cord was the primary site for the remaining 40 MEPNs, four (10%) of which presented in children. One extramedullary MEPN (9%) recurred in a 45-year-old woman, and five (11%) of 40 spinal tumors recurred and/or metastasized; two of four children with spinal MEPNs developed recurrences and a manifestation to the aggressive nature of the latter tumor in the spinal cord of children.

CONCLUSIONS

Based upon our experience, MEPN in children is more likely to present in the extramedullary soft tissues of the sacrococcygeal region where its behavior is more indolent than those tumors arising in the spinal cord in children.

Outcome predictors in the management of spinal myxopapillary ependymoma: an integrative survival analysis

OBJECTIVES

The results in earlier studies have described a variable association with age, extent of resection, and radiotherapy (RT) correlating with the survival of myxopapillary ependymomas. The aim of our study is to perform a survival analysis on patient data gathered from a comprehensive review of the literature and determine the influence of these factors on progression-free (PFS) and overall survival (OS).

METHODS

A PubMed search was performed to select the articles containing information about the critical events (recurrence/death), time to events, and treatment characteristics (extent of resection with or without RT) in the patients with spinal myxopapillary ependymomas.

RESULTS

A total of 337 patients with information regarding the critical events, time to events, and treatment characteristics was selected for the inclusion. Patients in gross-total resection group had better PFS and OS (P = 0.001, P = 0.000 respectively). The patients in older age group (>35 years) had better PFS (P = 0.008). Overall PFS did not improve if RT was combined with surgery compared with surgery alone; however, the adjuvant RT benefitted the patients age ≤35 years. RT dose >50 Gy had significant influence on the PFS (P = 0.034).

CONCLUSION

Gross-total resection plays the most important role in improving PFS and OS. Older patients had better PFS; however, the influence of adjuvant RT was significant in younger age groups. A dose of >50 Gy improves the results, but a randomized controlled study is warranted to arrive at a definite conclusion.

Primary Myxopapillary Ependymoma of the Medulla

OBJECTIVE

Myxopapillary ependymoma is a subclassification of ependymoma that is thought to be nearly exclusive to the conus medullaris or filum terminale. Primary intracerebral or brainstem myxopapillary ependymomas are rare.

CLINICAL PRESENTATION

An 8-year-old child presented with a 5-month history of nausea and vomiting and a 1-week history of headache. Magnetic resonance imaging revealed a nodular mass in the medulla with an associated cyst extending into the fourth ventricle.

INTERVENTION

A suboccipital craniotomy was performed, and a gross total resection of the lesion and cyst was achieved. Histological examination confirmed the diagnosis of myxopapillary ependymoma. A discussion of other reported cases of extraspinal myxopapillary ependymomas is presented.

CONCLUSION

This is the first report of a case of myxopapillary ependymoma, confirmed by histology, in the medulla. Although rare, myxopapillary ependymomas outside of the filum terminale do exist.