British Journal of Neurosurgery, 2014; Early Online: 1–3 © 2014 The Neurosurgical Foundation ISSN: 0268-8697 print / ISSN 1360-046X online DOI: 10.3109/02688697.2014.881464
SHORT REPORT
Disseminated spinal myxopapillary ependymoma in an adult at initial presentation: A case report and review of the literature David Straus, Lee A. Tan, Ippei Takagi & John E. O’ Toole
Br J Neurosurg Downloaded from informahealthcare.com by University of Maastricht on 05/28/14 For personal use only.
Departments of Neurosurgery, Rush University Medical Center, Chicago, IL, USA
Treatment
Abstract Disseminated spinal myxopapillary ependymoma (MPE) is extremely rare in adults. We report a 63-year-old man with chronic low-back pain found to have multiple MPEs in the thoracic, lumbar and sacral spine. Diagnostic and management strategies of disseminated MPE are discussed with a review of pertinent literature.
Given the location and typical appearance of the conus lesion, MPE was at the top of the differential diagnosis; however, other possibilities such as lymphoma or spinal metastases with occult primary were not entirely excluded. Therefore, surgical resection of the most easily accessible conus lesion was planned to establish definitive diagnosis and to facilitate overall treatment planning. The patient underwent standard posterior T12–L2 laminectomies and midline durotomy to approach the tumor. The cauda equina nerve roots were draped over and densely adherent to the tumor mass, which was filling the entire spinal canal. Evoked-electromyography stimulation was used (including all lower extremities and sphincter myotomes) to identify motor rootlets to facilitate safely debulking of the tumor mass using ultrasonic aspiration. Intraoperative biopsy was consistent with MPE as expected. A small amount of tumor tissue coating the cauda equina was not amenable to safe removal due to tight adherence to the motor rootlets, and thus was left in place, especially since the patient would already require adjuvant radiation for the thoracic and sacral lesions. Therefore, a near-total resection of the conus lesion was achieved without any change in neuromonitoring (Fig. 1D).
Keywords: ependymoma; intradural; intramedullary lesion; intramedullary tumor; myxopapillary ependymoma; spinal
Introduction Ependymomas are the most common intramedullary spinal tumors (WHO Grade II) and can disseminate via cerebrospinal fluid (CSF) pathways. The myxopapillary ependymoma (MPE) is a more benign variant (WHO Grade I) that occurs almost exclusively (95%) in the conus medullaris, cauda equina or filum terminale. Although rare, MPE can also disseminate through CSF often due to surgical manipulation and tumor capsule violation. It is very unusual, however, for MPE to present as disseminate disease at initial presentation without prior surgical intervention. We report an exceedingly rare case of disseminated MPE in an adult at initial presentation with a review of the pertinent literature.
Postoperative course The patient tolerated the procedure well. He was mobilized with physical therapy 2 days after surgery and was subsequently discharged home in stable condition. Final histopathology of the tumor was consistent with WHO Grade-I MPE (Fig. 2). He was referred to radiation oncology and underwent proton beam radiotherapy to the high thoracic, thoracolumbar and sacral lesions. His back pain completely resolved after surgery, though he did experience some urinary retention requiring self-catheterization at home. He has returned to work and his symptoms remain stable at 6-month follow-up.
Case report Presentation A 63-year-old man complained of progressive low-back pain for 3 months. He did not have any history of systemic malignancy. Physical examination was unremarkable. Magnetic resonance imaging (MRI) of the spine showed three separate intradural, contrast-enhancing lesions: an 8-mm extramedullary lesion at T2 located in the right ventrolateral aspect of the spinal cord without significant mass effect, an intramedullary conus lesion occupying the entire volume of the spinal canal extending from T12-L2, and a large sacral lesion expanding from S1-S3 with extension through the neural foramina (Fig. 1A–C). MRI of the brain was unremarkable.
Discussion MPE was first described as a distinct pathological entity by Kernohan in 1932. Traditional understanding has focused on
Correspondence: Lee A. Tan, MD, Departments of Neurosurgery, Rush University Medical Center, 1725 W. Harrison St. Suite 855, Chicago, IL 60612, USA. Tel: ⫹ 312-942-6644. Fax: ⫹ 312-563-3358. E-mail: [email protected] Received for publication 5 November 2013; accepted 30 December 2013
1
Br J Neurosurg Downloaded from informahealthcare.com by University of Maastricht on 05/28/14 For personal use only.
2
D. Straus et al.
Fig. 1. (A) Pre-operative sagittal T1 cervical spine MRI with contrast showing 8-mm ventral lesion. (B) Pre-operative sagittal T1 lumbar spine MRI with contrast showing large thoracolumbar and sacral lesions. (C) Pre-operative sagittal T2 lumbar spine MRI also demonstrating thoracolumbar and sacral lesions. (D) Post-operative sagittal T1 lumbar spinal MRI with contrast showing near-total resection of thoracolumbar lesion.
the focal and benign nature of this neoplasm earning it the WHO Grade-I classification. Prior to the advent of MRI, the incidence of disseminated MPE was thought to be negligible. The first report of disseminated MPE at initial diagnosis was published in a pediatric cohort in 2005.1 Numerous subsequent reports have re-affirmed the ability of MPE to disseminate in children prior to diagnosis. To our knowledge, there have been only two adult patients previously reported in literature with disseminated MPE at the time of initial diagnosis. Given the accepted low-grade nature of MPE, the traditional mainstay of treatment is gross-total resection (GTR).2 Although GTR has been shown to provide improved outcomes over subtotal resection, the impact of the exact surgical technique (i.e., en-bloc resection vs. intra-capsular techniques) on future dissemination or recurrence has not been demonstrated.3 Other studies have investigated the influence of molecular markers such as Ki-67, MIB-1 and p53 on MPE dissemination; but these attempts at molecular sub-stratification of MPE have failed to convincingly identify patients at high-risk of future dissemination.3 Our strategy has been to attempt en bloc resection if technically feasible without added risk of neurologic injury; in cases where excessive nerve-root traction or manipulation is required, internal debulking is accepted in deference to minimizing neurological morbidity. Recognition that recurrence and dissemination are not uncommon events in the clinical course of MPE has heralded the increasing use of adjuvant radiation therapy in treatment protocols. Reports have cited a decreased rate of post-operative recurrence or dissemination from 50% to 20% at 5-years. In the pediatric population, empiric adjuvant radiation therapy with 50 Gy after subtotal resection—which typically has been reserved for high-grade
Fig. 2. Pathology Specimens. (A) H&E at 4x, demonstrating multiphasic structure with myxoid vacuoles, fascicular regions and papillary structures. (B) H&E at 10x, demonstrating perivascular pseudorossettes and myxoid vacuoles. (C) H&E at 20x, demonstrating perivascular myxoid conglomerations. (D) GFAP immunohistochemistry at 20x, revealing a tumor strongly GFAP⫹. (E) EMA immunohistochemistry at 20x, without EMA positivity.
Br J Neurosurg Downloaded from informahealthcare.com by University of Maastricht on 05/28/14 For personal use only.
Disseminated adult spinal myxopapillary ependymoma 3 ependymomas—is being increasingly integrated into treatment algorithms.2 However, the true risks and benefits of using adjuvant radiation therapy have yet to be rigorously explored in clinical trials. This remains even more relevant to the pediatric population, where the incidence of primary disseminated MPE seems to be notably higher than in the adult population and where the risks of radiation treatment are more pronounced. At present, the best data available is Class III evidence, but it does seem to suggest optimal therapy for disseminated MPE should include maximal safe surgical excision of the “primary” lesion with adjuvant craniospinal external-beam radiotherapy of 50 Gy. Unfortunately, the rare nature of this presentation in an adult and the accompanying lack of longterm follow-up make estimating prognosis for patients like ours currently impossible.
Conclusion Although classified as WHO Grade I, MPEs can disseminate via CSF and presents with multifocal spinal lesions at initial diagnosis, even in adults. Optimal therapy for disseminated
MPE seems to include maximal safe surgical excision of the “primary” lesion with adjuvant craniospinal external-beam radiotherapy of 50 Gy from current available data.
Acknowledgment We would like to thank Dr. Matthew Fox for his assistance in the pathology images. Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.
References 1. Fassett DR, Pingree J, Kestle JR. The high incidence of tumor dissemination in myxopapillary ependymoma in pediatric patients: report of five cases and review of the literature. J Neurosurg 2005;102:59–64. 2. Gilbert MR, Ruda R, Soffietti R. Ependymomas in adults. Curr Neurol Neurosci Rep 2010;10:240–7. 3. Rezai AR, Woo HH, Lee M, et al. Disseminated ependymomas of the central nervous system. J Neurosurg 1996;85:618–24.
SHORT REPORT
Disseminated spinal myxopapillary ependymoma in an adult at initial presentation: A case report and review of the literature David Straus, Lee A. Tan, Ippei Takagi & John E. O’ Toole
Br J Neurosurg Downloaded from informahealthcare.com by University of Maastricht on 05/28/14 For personal use only.
Departments of Neurosurgery, Rush University Medical Center, Chicago, IL, USA
Treatment
Abstract Disseminated spinal myxopapillary ependymoma (MPE) is extremely rare in adults. We report a 63-year-old man with chronic low-back pain found to have multiple MPEs in the thoracic, lumbar and sacral spine. Diagnostic and management strategies of disseminated MPE are discussed with a review of pertinent literature.
Given the location and typical appearance of the conus lesion, MPE was at the top of the differential diagnosis; however, other possibilities such as lymphoma or spinal metastases with occult primary were not entirely excluded. Therefore, surgical resection of the most easily accessible conus lesion was planned to establish definitive diagnosis and to facilitate overall treatment planning. The patient underwent standard posterior T12–L2 laminectomies and midline durotomy to approach the tumor. The cauda equina nerve roots were draped over and densely adherent to the tumor mass, which was filling the entire spinal canal. Evoked-electromyography stimulation was used (including all lower extremities and sphincter myotomes) to identify motor rootlets to facilitate safely debulking of the tumor mass using ultrasonic aspiration. Intraoperative biopsy was consistent with MPE as expected. A small amount of tumor tissue coating the cauda equina was not amenable to safe removal due to tight adherence to the motor rootlets, and thus was left in place, especially since the patient would already require adjuvant radiation for the thoracic and sacral lesions. Therefore, a near-total resection of the conus lesion was achieved without any change in neuromonitoring (Fig. 1D).
Keywords: ependymoma; intradural; intramedullary lesion; intramedullary tumor; myxopapillary ependymoma; spinal
Introduction Ependymomas are the most common intramedullary spinal tumors (WHO Grade II) and can disseminate via cerebrospinal fluid (CSF) pathways. The myxopapillary ependymoma (MPE) is a more benign variant (WHO Grade I) that occurs almost exclusively (95%) in the conus medullaris, cauda equina or filum terminale. Although rare, MPE can also disseminate through CSF often due to surgical manipulation and tumor capsule violation. It is very unusual, however, for MPE to present as disseminate disease at initial presentation without prior surgical intervention. We report an exceedingly rare case of disseminated MPE in an adult at initial presentation with a review of the pertinent literature.
Postoperative course The patient tolerated the procedure well. He was mobilized with physical therapy 2 days after surgery and was subsequently discharged home in stable condition. Final histopathology of the tumor was consistent with WHO Grade-I MPE (Fig. 2). He was referred to radiation oncology and underwent proton beam radiotherapy to the high thoracic, thoracolumbar and sacral lesions. His back pain completely resolved after surgery, though he did experience some urinary retention requiring self-catheterization at home. He has returned to work and his symptoms remain stable at 6-month follow-up.
Case report Presentation A 63-year-old man complained of progressive low-back pain for 3 months. He did not have any history of systemic malignancy. Physical examination was unremarkable. Magnetic resonance imaging (MRI) of the spine showed three separate intradural, contrast-enhancing lesions: an 8-mm extramedullary lesion at T2 located in the right ventrolateral aspect of the spinal cord without significant mass effect, an intramedullary conus lesion occupying the entire volume of the spinal canal extending from T12-L2, and a large sacral lesion expanding from S1-S3 with extension through the neural foramina (Fig. 1A–C). MRI of the brain was unremarkable.
Discussion MPE was first described as a distinct pathological entity by Kernohan in 1932. Traditional understanding has focused on
Correspondence: Lee A. Tan, MD, Departments of Neurosurgery, Rush University Medical Center, 1725 W. Harrison St. Suite 855, Chicago, IL 60612, USA. Tel: ⫹ 312-942-6644. Fax: ⫹ 312-563-3358. E-mail: [email protected] Received for publication 5 November 2013; accepted 30 December 2013
1
Br J Neurosurg Downloaded from informahealthcare.com by University of Maastricht on 05/28/14 For personal use only.
2
D. Straus et al.
Fig. 1. (A) Pre-operative sagittal T1 cervical spine MRI with contrast showing 8-mm ventral lesion. (B) Pre-operative sagittal T1 lumbar spine MRI with contrast showing large thoracolumbar and sacral lesions. (C) Pre-operative sagittal T2 lumbar spine MRI also demonstrating thoracolumbar and sacral lesions. (D) Post-operative sagittal T1 lumbar spinal MRI with contrast showing near-total resection of thoracolumbar lesion.
the focal and benign nature of this neoplasm earning it the WHO Grade-I classification. Prior to the advent of MRI, the incidence of disseminated MPE was thought to be negligible. The first report of disseminated MPE at initial diagnosis was published in a pediatric cohort in 2005.1 Numerous subsequent reports have re-affirmed the ability of MPE to disseminate in children prior to diagnosis. To our knowledge, there have been only two adult patients previously reported in literature with disseminated MPE at the time of initial diagnosis. Given the accepted low-grade nature of MPE, the traditional mainstay of treatment is gross-total resection (GTR).2 Although GTR has been shown to provide improved outcomes over subtotal resection, the impact of the exact surgical technique (i.e., en-bloc resection vs. intra-capsular techniques) on future dissemination or recurrence has not been demonstrated.3 Other studies have investigated the influence of molecular markers such as Ki-67, MIB-1 and p53 on MPE dissemination; but these attempts at molecular sub-stratification of MPE have failed to convincingly identify patients at high-risk of future dissemination.3 Our strategy has been to attempt en bloc resection if technically feasible without added risk of neurologic injury; in cases where excessive nerve-root traction or manipulation is required, internal debulking is accepted in deference to minimizing neurological morbidity. Recognition that recurrence and dissemination are not uncommon events in the clinical course of MPE has heralded the increasing use of adjuvant radiation therapy in treatment protocols. Reports have cited a decreased rate of post-operative recurrence or dissemination from 50% to 20% at 5-years. In the pediatric population, empiric adjuvant radiation therapy with 50 Gy after subtotal resection—which typically has been reserved for high-grade
Fig. 2. Pathology Specimens. (A) H&E at 4x, demonstrating multiphasic structure with myxoid vacuoles, fascicular regions and papillary structures. (B) H&E at 10x, demonstrating perivascular pseudorossettes and myxoid vacuoles. (C) H&E at 20x, demonstrating perivascular myxoid conglomerations. (D) GFAP immunohistochemistry at 20x, revealing a tumor strongly GFAP⫹. (E) EMA immunohistochemistry at 20x, without EMA positivity.
Br J Neurosurg Downloaded from informahealthcare.com by University of Maastricht on 05/28/14 For personal use only.
Disseminated adult spinal myxopapillary ependymoma 3 ependymomas—is being increasingly integrated into treatment algorithms.2 However, the true risks and benefits of using adjuvant radiation therapy have yet to be rigorously explored in clinical trials. This remains even more relevant to the pediatric population, where the incidence of primary disseminated MPE seems to be notably higher than in the adult population and where the risks of radiation treatment are more pronounced. At present, the best data available is Class III evidence, but it does seem to suggest optimal therapy for disseminated MPE should include maximal safe surgical excision of the “primary” lesion with adjuvant craniospinal external-beam radiotherapy of 50 Gy. Unfortunately, the rare nature of this presentation in an adult and the accompanying lack of longterm follow-up make estimating prognosis for patients like ours currently impossible.
Conclusion Although classified as WHO Grade I, MPEs can disseminate via CSF and presents with multifocal spinal lesions at initial diagnosis, even in adults. Optimal therapy for disseminated
MPE seems to include maximal safe surgical excision of the “primary” lesion with adjuvant craniospinal external-beam radiotherapy of 50 Gy from current available data.
Acknowledgment We would like to thank Dr. Matthew Fox for his assistance in the pathology images. Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.
References 1. Fassett DR, Pingree J, Kestle JR. The high incidence of tumor dissemination in myxopapillary ependymoma in pediatric patients: report of five cases and review of the literature. J Neurosurg 2005;102:59–64. 2. Gilbert MR, Ruda R, Soffietti R. Ependymomas in adults. Curr Neurol Neurosci Rep 2010;10:240–7. 3. Rezai AR, Woo HH, Lee M, et al. Disseminated ependymomas of the central nervous system. J Neurosurg 1996;85:618–24.
