Malignant behavior of myxopapillary ependymoma. Report of three cases

Anaplastic myxopapillary ependymoma: A case report and review of literature

BACKGROUND

Myxopapillary ependymoma (MPE) is a pathological grade I tumor that arises in the filum terminale. MPE with anaplastic features is extremely rare, and only 5 cases have shown malignancy at the time of recurrence.

CASE SUMMARY

The patient (a 46-year-old woman) had undergone a MPE operation 30 years ago. After subtotal resection of the tumor located in L4-S1, it had a solid component that extended to the adjacent subcutaneous region. Histologically, the tumor consisted of a typical MPE with anaplastic features. The anaplastic areas of the tumor showed hypercellularity, a rapid mitotic rate, vascular proliferation, and connective tissue proliferation. Pleomorphic cells and atypical mitotic figures were occasionally observed. The MIB-1 index in this area was 12.3%. The immunohistochemical study showed immunoreactivity for vimentin, glial fibrillary acidic protein and S100. The morphological pattern and immunohistochemical profile were consistent with anaplastic MPE. The patient tolerated surgery well without new neurological deficits. She underwent local irradiation for the residual tumor and rehabilitation.

CONCLUSION

Although extremely rare, anaplastic MPE occurs in both pediatric and adult patients, similar to other ependymomas. At a minimum, close monitoring is recommended, given concerns about aggressive biological potential. In the future, further study is needed to determine the WHO classification criteria and genetic indicators of tumor progression. The possibility of malignant transformation of MPE should be taken into account, and patients with MPE should be treated with care and follow-up.

Anaplastic Transformation in Myxopapillary Ependymoma: A Report of 2 Cases and Review of the Literature

Myxopapillary ependymoma (MPE) is a relatively common neoplasm arising primarily in the filum terminale/lumbosacral region of the spinal cord. It is designated as a grade I tumor in the most recent WHO Classification of Tumours of the CNS, although aggressive clinical behavior can be observed, especially in cases arising in an extradural location. Anaplastic transformation in MPE is exceedingly rare with <20 examples reported in the English literature, and consensus on diagnostic features and definitive grading remain to be determined. Here, we present 2 cases of recurrent MPE with anaplastic features, both of which had histology consistent with conventional MPE as well as areas with significant atypia, frequent mitotic figures, elevated Ki-67 proliferation indices (>10%-50%), necrosis, and focal vascular proliferation. Targeted next-generation sequencing panels revealed no definitive pathogenic mutations or fusion proteins in either case. Copy number profiling, methylation profiling, and t-Distributed Stochastic Neighbor Embedding were performed to investigate the molecular characteristics of these tumors. To the best of our knowledge, these are the first reported cases of MPE with anaplastic features with methylation profiling data. In addition, we review the literature and discuss common histologic and molecular findings associated with anaplastic features in MPE.

Spinal Intradural Extramedullary Ependymoma with Intracranial Metastasis and Leptomeningeal Spread: A Case Report and Comprehensive Review of Literature

Dorsolumbar intradural extramedullary ependymoma is a rare entity. Spinal metastases in patients with intracranial ependymoma are well described, but it is extremely rare for a spinal ependymoma to metastasize to brain. We describe a case of aggressive dorsolumbar intradural extramedullary ependymoma mimicking arachnoid cyst radiologically, which developed intracranial metastasis.

Myxopapillary ependymoma with anaplastic features: A case report with review of the literature

Background:

Myxopapillary ependymoma (MPE) with anaplastic features is extremely rare, with only three case reports in the literature.

Case Description:

We report the case of a MPE with anaplastic features in a 24-year-old female who presented with a dominant lumbar mass along with intracranial and sacral metastases. Upon gross total resection of the dominant tumor located at L2-L3, it appeared to arise from the filum terminale, and had a solid component in addition to soft or necrotic areas. Histologically, the tumor was composed of the two classic components of MPE: (1) low-grade ependymal cells surrounding blood vessels, producing the papillary appearance and (2) perivascular myxoid material between blood vessels and ependymal cells, creating the myxopapillary appearance. The high-grade anaplastic component showed hypercellularity, brisk mitotic rate, and vascular proliferation, with frequent pleomorphic cells and atypical mitotic figures. It was positive for vimentin and glial fibrillary acidic protein (GFAP); negative for epithelial membrane antigen (EMA), CAM5.2, creatine kinase 7 (CK7), CK20; and the MIB-1 index (Ki-67) was 8–38%. Ten months after initial resection, follow-up magnetic resonance imaging revealed new lesions in (1) the hypothalamus, (2) the left pons, and (3) the left medial temporal lobe, which were treated with radiosurgery. Eight months later (18 months from initial surgery), the patient underwent thoracic laminectomy for a large leptomeningeal metastasis at T6 and T8.

Conclusion:

The present case of MPE with anaplastic features is the fourth case on record in the medical literature.

Metastases of spinal myxopapillary ependymoma: unique characteristics and clinical management

OBJECTIVE

Myxopapillary ependymoma is a benign WHO Grade I tumor most commonly located in the conus–cauda equina region of the spine. Although this tumor is defined by an overall excellent survival, dissemination throughout the whole neuraxis occurs frequently. The current study evaluated the clinical characteristics and significance of myxopapillary ependymoma metastases.

METHODS

Patients who underwent surgery from 2005 to 2015 for treatment of spinal myxopapillary ependymoma were included in the study. Charts were reviewed for primary tumor symptoms and initial treatment, local recurrence, response to salvage therapy, and presence and behavior of distant metastases.

RESULTS

Nineteen patients with spinal myxopapillary ependymoma were included in the study (52.6% female). The median age at first diagnosis was 32 years old (range 9–58 years old), and 26.3% were ≤ 18 years old. The median follow-up of all included patients was 48 months (range 6–456 months). Of the primary tumors, 84.2% were located in the lower thoracic or upper lumbar spine, spanning 1–3 levels in 94.7%. All patients underwent surgery for initial treatment: in 78.9% a gross-total resection (GTR) was achieved, with adjuvant radiation therapy (RT) in 20%. Of the 21.2% who underwent a subtotal resection (STR), 75% underwent postoperative RT. Tumor progression was noted in 26.3% of patients after a median 36-month follow-up (range 12–240 months). In 57.9% of patients, distant metastases were found, of which 36.4% were present at initial diagnosis. Further metastases occurred within a median of 20 months (range 2–360 months). Following a diagnosis of metastatic tumor, 72.7% did not show progression and no symptoms were observed during a median follow-up of 36 months (range 6–216 months). Metastases occurred in all parts of the neuroaxis, but were principally localized in the thoracic and sacral spine in 38.9% and 33.3%, respectively; the brain was involved in 11.1%. In 54.5%, more than 1 level was affected. Overall survival was 100% with an excellent clinical and neurological outcome in 78.9% of cases.

CONCLUSIONS

Metastatic dissemination within the CNS can be observed in many patients with myxopapillary ependymoma. GTR of the primary tumor should be the primary treatment goal, and additional RT is recommended after STR. For distant metastases of myxopapillary ependymoma without clinical manifestation, close clinical and MRI follow-up represents a sufficient strategy because most of the metastases remain asymptomatic and do not show progression over time. Additional resection or irradiation as salvage therapy would be recommended if metastases become symptomatic.

Remarkable efficacy of temozolomide for relapsed spinal myxopapillary ependymoma with multiple recurrence and cerebrospinal dissemination: a case report and literature review

PURPOSE

Myxopapillary ependymomas are intradural tumors which grow from the terminal filum of the spinal cord. Although they are classified as WHO grade I, they sometimes cause cerebrospinal fluid dissemination or local recurrence. In this report, we describe a case in that temozolomide (TMZ) showed remarkable efficacy on a recurrent spinal myxopapillary ependymoma.

CASE REPORT

A 26-year-old female underwent resection of an intradural myxopapillary ependymoma at L5 initially. Although an en bloc total resection, including the capsule, could be achieved, she needed two additional tumor resection surgeries with postoperative radiotherapy at L4 and at L3 (2 and 6 years after the initial surgery, respectively). Moreover, 4 years after the initial surgery, a disseminated metastatic tumor occurred at T11/12 and local radiotherapy was not effective. After the third surgery, an aggressive adjuvant therapy was necessary because there was a high risk of another recurrence. Therefore, TMZ was administered for 1 year. After 6 months of TMZ treatment, remarkably, the disseminated metastatic tumor at T11/12 had disappeared completely. Presently, 6 years after finishing the TMZ treatment, the follow-up MRI has shown no recurrence in the brain and whole spine.

CONCLUSIONS

TMZ is usually used in the treatment of glioblastoma and, recently, it has been reported to be effective for the lower grade spinal gliomas including spinal intramedullary ependymomas. However, for myxopapillary ependymomas, there has been no report that TMZ is effective. According to our results, TMZ could be one of the possible candidates for adjuvant therapy in multiple recurrent myxopapillary ependymomas.

Benign ependymoma with extensive intracranial and spinal cerebrospinal fluid dissemination: case report and literature review

Myxopapillary ependymoma (MPE) is a rare variant of ependymoma that is most commonly located in the cauda equina and filum terminale. We present a case of 23-year-old man diagnosed with MPE in the fourth ventricle and sacral canal area with extensive disseminated lesions along the cerebrospinal ventricular system. Additionally, a molecular pathological diagnosis was performed. The patient underwent a craniotomy and a lumbar laminectomy. In the course of 18 months of follow-up, the patient have recovered very well.

Primary Seeding of Myxopapillary Ependymoma: Different Disease in Adult Population? Case Report and Review of Literature

Myxopapillary ependymoma (MPE) is a slow-growing tumor, occurring most often in adults. It originates from the filum terminale in the area of the conus medullaris and cauda equina and is considered a benign lesion. Despite this classification, however, recurrence after both partial and gross total resection is well known. In the pediatric population, primary MPE seeding and generally more aggressive clinical course is well documented and treated through gross total resection, if possible, followed by irradiation. In adults, however, primary MPE seeding is rarely seen. There are few prior reports describing primary metastases into multiple spinal locations in an adult before resection of an MPE. The reason for this difference among pediatric and adult MPE remains unclear. We present the case of a 32-year-old man with primary seeding of an MPE into multiple lumbosacral areas. The patient underwent gross total resection of the lesions and had an uneventful postoperative course. Primary seeding could be a sign of aggressive behavior in this tumor. Complete craniospinal magnetic resonance imaging studies should be done before and after surgery in patients who present with a multifocal primary MPE. Furthermore, patients with a history of primary tumor seeding of MPE should be thoroughly evaluated radiologically. Unlike in pediatric populations, the need for postoperative irradiation in adults is less clear and further studies-particularly genetic ones-are warranted.

Spinal myxopapillary ependymoma with interval drop metastasis presenting as cauda equina syndrome: case report and review of literature

Myxopapillary ependymoma is a benign slow-growing tumour, arising predominantly in the region of the filum terminale. It has been designated histologically as grade I neoplasm according to the 2007 WHO classification. Despite this benign character dissemination and metastasis along the cerebrospinal axis and metastasis to distant sites have occasionally been reported. There have been previously reported cases of drop metastasis from MPE, however in three of these cases the drop metastasis was diagnosed with concurrent primary spinal MPE. There has been only one previously published case of interval drop metastasis in a case of operated spinal MPE in literature. We hereby present the second case of interval drop metastasis in a case of conus MPE, with history of having undergone a subtotal resection and post operative adjuvant radiotherapy prior to second surgery. The patient presented months after the primary surgery with symptoms of cauda equina syndrome attributable to the drop metastasis.

Outcomes following myxopapillary ependymoma resection: the importance of capsule integrity

OBJECT While extent of resection has been shown to correlate with outcomes after myxopapillary ependymoma (MPE) resection, the effect of capsular violation has not been well studied. The role of adjuvant radiation also remains controversial. In this paper the authors' goals were to evaluate outcomes following resection of MPE based on intraoperative capsular violation and to explore the role of adjuvant radiotherapy in cases of capsular violation. METHODS A retrospective review of patients undergoing resection of MPE at 2 academic institutions between 1990 and 2013 was performed. Cases with dissemination at presentation, less than 12 months of follow-up, or incomplete records were excluded. Extent of resection was defined as en bloc if all visible tumor was removed without capsular violation, gross-total resection (GTR) if all visible tumor was removed, but with capsular violation, and subtotal resection (STR) if a known residual was left at the time of surgery. Postoperative MR images were reviewed to confirm the extent of resection. Primary outcomes were progression-free survival (PFS) and overall recurrence rates. The effects of extent of resection, capsular violation, and adjuvant radiotherapy on recurrence rates and PFS were analyzed using Kaplan-Meier statistics. Associations between recurrence and preoperative variables were evaluated using Fisher exact methods and t-tests where appropriate. RESULTS Of the 107 patients reviewed, 58 patients (53% were male) met inclusion criteria. The mean age at surgery was 40.8 years (range 7-68 years). The median follow-up was 51.5 months (range 12-243 months). Extent of resection was defined as en bloc in 46.5% (n = 27), GTR in 34.5% (n = 20), and STR in 18.9% (n = 11). No recurrences were noted in the en bloc group, compared with 15% (n = 3) and 45% (n = 5) in the GTR and STR groups. En bloc resection was achieved most frequently in tumors involving the conus. Twelve patients (20%) underwent adjuvant radiotherapy following either STR or GTR. The overall recurrence rate was 13.8% (n = 8), and the 5-year PFS was 81%. Capsular violation was associated with a higher recurrence rate (p = 0.005). Adjuvant radiotherapy showed a nonsignificant trend of lower recurrence rates (16.7% vs 31.6%, p = 0.43) and longer PFS at 5 years (83.3% vs 49.9%, p = 0.16) in cases of capsular violation. CONCLUSIONS A strong correlation between capsular violation and recurrence was found following removal of MPE and should be assessed when defining extent of resection in future studies. Although the use of adjuvant radiotherapy in cases of capsular violation showed a trend toward improved PFS, further investigation is needed to establish its role as salvage therapy also appears to be effective at halting disease progression.

Spinal drop metastasis in myxopapillary ependymoma: a case report and a review of treatment options

Myxopapillary ependymoma (MPE) is a World Health Organization grade I ependymoma that is quite rare and generally thought to be benign. Possible drop metastasis from MPE has been reported three times in the literature; in each case there were cotemporaneous additional MPE lesions. We report the case of a man who had a piecemeal gross total resection of a MPE at L1-L3 followed by adjuvant external beam radiotherapy (EBRT) who presented sixteen months later with a lesion in the thecal sac consistent with drop metastasis. A subtotal resection and adjuvant EBRT were performed. The patient has been disease-free in follow-up 27 months from the second surgery. A review of the literature regarding the treatment for MPE showed that gross total resection is optimal initial management. Several retrospective studies supported the role of adjuvant radiotherapy in enhancing local control and progression-free survival. Chemotherapy has a minimal role in the management of MPE.

The nature of double concomitant myxopapillary ependymoma: report of a case

Myxopapillary ependymomas are almost exclusively seen at the conus medullaris/filum terminale/cauda equina region, usually as solitary space-occupying lesions. The authors report the case of a 14-year-old boy with double concomitant myxopapillary ependymoma, proximal and caudal on the filum terminale in which a totally gross removal was achieved in two stages. This presentation is rare and, so far, we have known just three similar cases that were previously reported in children. The true nature of these lesions is controversial, and while some argue that they are related to metastatic seeding, others consider them independent lesions developing synchronously. A review on dissemination of spinal myxopapillary ependymomas was done.

Tumor control after surgery for spinal myxopapillary ependymomas: distinct outcomes in adults versus children: a systematic review

OBJECT

Myxopapillary ependymomas (MPEs) are rare WHO Grade I tumors found in the conus medullaris, cauda equina, and filum terminale. Treatment generally consists of resection with or without adjuvant radiotherapy. Evidence-based guidelines for surgical management are lacking due to the rarity of this tumor.

METHODS

An English-language PubMed search was performed using the key words "myxopapillary" and "ependymoma." Reports describing fewer than 3 patients or those lacking data on the extent of resection or radiotherapy were excluded. A total of 28 articles describing 475 patients met the authors' inclusion criteria. Patients were grouped by extent of resection and whether or not they underwent adjuvant radiotherapy. Differences in recurrence rates were assessed by chi-square test.

RESULTS

The overall recurrence rate was 15.5% in patients treated by gross-total resection (GTR) and 32.6% in patients treated by subtotal resection (STR), irrespective of whether they underwent adjuvant therapy (p < 0.001). Regardless of the extent of resection, adjuvant radiotherapy was not associated with a decrease in recurrence rates. The overall recurrence rate was 15.6% in patients who underwent GTR and radiotherapy compared with 15.9% in patients who underwent GTR alone (p = 0.58), and it was 29.3% in patients who underwent STR and radiotherapy compared with 35.1% in those who underwent STR alone (p = 0.53). The difference between recurrence rates for patients who underwent GTR alone versus STR and radiotherapy was statistically significant (p = 0.02). Subgroup analysis demonstrated significantly higher recurrence rates in pediatric patients compared with adults (40.5% vs 23.4%, respectively; p = 0.02). Even in the setting of GTR alone, recurrence rates were higher in pediatric patients (65% vs 7.6%; p < 0.001).

CONCLUSIONS

Gross-total resection alone is associated with decreased recurrence rates compared with STR with or without radiotherapy. The authors' results suggest that treatment goals should include attempted GTR whenever possible. The observation that children benefitted from radiation therapy to a greater extent than did adults suggests that biological differences between tumors in these patient populations warrants more rigorous scientific studies.

Pathology of Spinal Ependymomas

BACKGROUND:

Ependymomas constitute approximately 40% of primary intraspinal tumors. Current World Health Organization (WHO) grading may not correlate with observed progression-free survival (PFS).

OBJECTIVE:

This retrospective study of prospectively collected data examines whether PFS is influenced by the histological grade or by the extent of resection. It also analyzes the usage and effectiveness of postoperative adjuvant radiotherapy.

METHODS:

We reviewed 134 consecutive patients with ependymomas of all grades. Pathology slides were re-reviewed and the histological grades were confirmed by a single neuropathologist. Postoperative residual or recurrence was evaluated with follow-up magnetic resonance imaging.

RESULTS:

There were 85 male and 49 female patients, ranging from 10 to 79 (median 41) years of age. Thirty patients had WHO grade I tumors, 101 had grade II tumors, and 3 had grade III tumors. Kaplan-Meier analysis of PFS demonstrated a mean duration of 6 years for grade I, 14.9 years for grade II, and 3.7 years for grade III (P &lt; .001). In grade II ependymomas, mean PFS was 11.2 years with subtotal resection and 17.8 years with gross total resection (P &lt; .01). PFS of patients who underwent subtotal resection was not significantly changed by adjuvant radiotherapy (P &lt; .36).

CONCLUSION:

Patients with grade II ependymoma have significantly longer PFS than patients with grade I ependymoma. The extent of resection did not affect PFS in grade I ependymoma but it did in grade II. Contrary to its higher grade, WHO grade II ependymoma carries a better prognosis than WHO grade I ependymoma.

Craniospinal dissemination of filum myxopapillary ependymoma following spinal trauma: case report and literature review

BACKGROUND

Myxopapillary ependymoma is a rare benign variant of ependymoma, occurring most commonly in the cauda equina/filum terminale of the spinal cord. It is rare in pediatric patients. Dissemination of the myxopapillary ependymoma along the neuraxis is uncommon both in adults and pediatric patients.

METHODS

We report a 16-year-old boy with dissemination of the myxopapillary ependymoma along the neuraxis following spinal trauma. The possible mechanisms of tumor dissemination are discussed with a review of the literature.

Multicentric extramedullary myxopapillary ependymomas: Two case reports and literature review

Background:

Ependymoma has been described typically as an intramedullary tumor derived from ependymal cells. Intradural extramedullary presentation is rarely described and almost always as a unique lesion. Myxopapillary ependymoma is a histological variant that distinguishes from the ordinary type of ependymoma because of its generally better prognosis. We present two cases of multicentric extramedullary myxopapillary ependymomas.

Case Description:

Case 1 was a 30-year-old man with progressive paresthesia and paresis in the lower limbs, urinary sphincter disturbances, gait instability, ataxia, and chronic low back pain with multiple intradural extramedullary lesions at C2-C3, D2-D4-D5, and D12-L1. Case 2 was a 32-year-old man, presented with low back pain and mild paresthesia in the right lower limb. Magnetic resonance imaging (MRI) showed multiple intradural extramedullary lesions with homogeneous enhancement after gadolinium injection at C7, D2, D4, D5, D8, D10, D11, L1, L3, L5, S1, and S2. Complete tumor resection of the approached tumors was archived in both cases. Histological studies confirm myxopapillary ependymomas. Patient's neurologic outcome was good and no residual tumor was present at MRI control at 10 years in case 1 and 12 months in case 2.

Conclusions:

We report the first two cases of multicentric extramedullary myxopapillary ependymomas, this etiology must be taken into account in the differential diagnosis of intradural extramedullary tumors.

Acute neurological deterioration as a result of two synchronous hemorrhagic spinal ependymomas

Background:

Ependymomas are the most common intramedullary tumors in adults and are the most common in mid-adult years. The presence of synchronous ependymomas in different sites of the spine is not common and it is even more infrequent to find hemorrhage from a spinal ependymoma as a cause of neurological deterioration.

Case Description:

A 32-year-old man presented with back pain and progressive paraparesia. Magnetic resonance (MR) showed two intradural extramedullary lesions on spinal canal with signs of acute hemorrhage. The patient underwent emergent surgical decompression and resection. Pathology revealed myxopapillary ependymomas.

Conclusion:

To our knowledge, we report the first case of a patient with acute neurological deterioration as a consequence of synchronous bleeding of two spinal ependymomas located at different levels in the spinal cord. This study illustrates the importance of recognizing the rare, but known occurrence of acute neurological deterioration after spontaneous hemorrhage in spinal ependymomas.

Primary myxopapillary ependymoma of the fourth ventricle with cartilaginous metaplasia: a case report and review of the literature

Myxopapillary ependymoma (MPE), which is a benign histological subtype of ependymoma, is found predominantly in the cauda equina region. It occurs rarely in the brain and mostly as a metastatic deposit from a spinal lesion. The occurrence of primary intracranial MPE is exceptional, with only 11 cases reported to date. We report an additional case of intracranial MPE, which is the third reported case in the fourth ventricle. The tumor manifested in a 50-year-old lady, who presented with features of raised intracranial pressure. A gross total resection of the tumor was achieved. Histologically, the tumor had characteristic features of MPE with focal metaplastic cartilaginous deposit. On further evaluation, there was no evidence of a primary tumor in the spinal cord. Intracranial MPE needs further evaluation by craniospinal MRI to exclude an unrecognized primary in the spinal region, which could warrant surgical attention.

Long-term surgical outcomes for myxopapillary ependymomas of the cauda equina

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To evaluate our treatment strategy for myxopapillary ependymomas of the cauda equina.

SUMMARY OF BACKGROUND DATA

Some patients with myxopapillary ependymoma develop cerebrospinal fluid (CSF) dissemination leading to poor prognosis. Because of the rarity of this tumor, there is no consensus on its optimal treatment options and prognosis.

METHODS

We reviewed 25 cases of myxopapillary ependymomas, treated surgically between 1972 and 2005. The mean postoperative follow-up period was 10.4 years. The effects of surgical margins at surgery and postoperative radiotherapy on tumor recurrence and prognosis were investigated.

RESULTS

In 15 patients, total resection achieved (6 cases of en bloc resection without postoperative radiation, and in 9 cases piecemeal resection) was followed by whole brain and spinal cord radiation or local irradiation. Fourteen of these patients survived without tumor recurrence. In 1 case of total resection without radiotherapy, the tumor capsule was violated intraoperatively and local recurrence occurred 2 years after surgery. In 4 patients, the tumors were removed subtotally. Of these, 2 patients who received radiation (24 Gy) only to the whole brain and spinal cord developed recurrence, and 2 who received whole brain and spinal cord radiation (24 Gy) supplemented with local radiation (46 Gy) developed no recurrence. The remaining 6 patients received partial resection after local radiation (40-50 Gy) alone, and all 6 died of CSF dissemination.

CONCLUSION

The results of the present study indicate that the surgical margin obtained at the initial surgery and the extent and amount of postoperative radiation can be crucial factors determining the prognosis of patients with myxopapillary ependymoma. Although this tumor is histologically benign, CSF dissemination can occur once tumor capsule is violated, before or during surgery. Therefore, early diagnosis is essential, and a therapeutic strategy including radiotherapy, on the assumption that this tumor is malignant, should be established.

Ependymal tumors

Ependymomas represent a heterogeneous group of glial tumors whose biological behavior depends on various histological, molecular, and clinical variables. The scope of this chapter is to review the clinical and histo-logical features as well as the molecular genetics of ependymomas with special emphasis on their influence on tumor recurrence and prognosis. Furthermore, potential molecular targets for therapy are outlined.

Myxopapillary ependymoma of lumbosacral region with metastasis to both cerebellopontine angles: report of a rare case

INTRODUCTION

Myxopapillary ependymomas are low grade tumours that are known to recur locally even after complete excision, but metastasis to distant sites is extremely uncommon.

CASE REPORT

We report an unusual case of lumbo-sacral myxopapillary ependymoma in a 13-year-old boy with metastasis to both cerebellopontine angles. To the best of our knowledge, this is the youngest patient of metastatic myxopapillary ependymoma.

Extradural ependymal tumor with myxopapillary and ependymoblastic differentiation in a case of Schinzel-Giedion syndrome

Primary extradural ependymomas are rare neoplasms usually of the myxopapillary type. Reports on malignant primary extradural ependymal tumors are exceptionally rare. We here report on a 3-year-old boy with Schinzel-Giedion syndrome (SGS), who presented with lumbar spina bifida occulta and a progressive extraspinal lesion in the subcutaneous sacrococcygeal region. Microscopic examinations revealed an uncommon ependymal tumor with well-differentiated regions reflecting myxopapillary ependymoma and highly anaplastic regions with numerous mitoses, necroses, ependymal rosettes and ependymoblastic rosettes. Final neuropathologic diagnosis was an extraspinal anaplastic ependymal tumor with myxopapillary and ependymoblastic differentiation, corresponding to WHO grade IV. SGS is a very rare disorder with a likely autosomal recessive pattern of inheritance. So far, 42 cases have been reported, among them 7 were diagnosed to have malignant neoplasms, including three malignant sacrococcygeal teratomas, two sacrococcygeal primitive neuroectodermal tumors (PNET), one hepatoblastoma and one malignant kidney tumor. The present case is the first report on an ependymal tumor with a mixture of myxopapillary, anaplastic and ependymoblastic features and the first report on an ependymal tumor arising on the genetic background of SGS.

Intracranial retrograde dissemination in filum terminale myxopapillary ependymomas

Myxopapillary ependymomas (ME) are considered benign tumours (WHO grade I) of the central nervous system with long term survival rates and a tendency to local recurrence. However an aggressive course has occasionally been described, leading to CSF dissemination and even systemic metastases. We describe the case of a 23-year-old man diagnosed with intracranial subarachnoid dissemination of a filum terminale ME three years after the initial diagnosis. We have performed a careful review of the literature on CSF dissemination in ME and finally propose treatment of these cases.

Myxopapillary Ependymoma and Fatty Filum in an Adult with Tethered Cord Syndrome: A Shared Embryological Lesion? Case Report

OBJECTIVE AND IMPORTANCE:

Myxopapillary ependymoma and fatty fila are traditionally thought to arise via completely different pathophysiologies. Recognition of these distinct pathologies in the same patient is important for appropriate treatment and prognosis.

CLINICAL PRESENTATION:

A 28-year-old woman presented with low back pain, bilateral leg radiculopathies, and mild leg weakness suggestive of tethered cord syndrome. Magnetic resonance imaging revealed lesions in the area of the conus medullaris consistent with a myxopapillary ependymoma and fatty filum.

INTERVENTION:

Under the surveillance of intraoperative electromyographic monitoring, the patient underwent an L4–S2 laminectomy for transection of the fatty filum and gross total resection of the mass. Histopathological examination confirmed the presence of these two distinct pathologies.

CONCLUSION:

We report an unusual case of a myxopapillary ependymoma coexisting with a fatty filum in an adult patient. To the best of our knowledge, this association has not yet been reported. This raises the interesting question of a possible associative or causative relationship between these distinct pathologies, which have traditionally been thought to arise from different mechanisms.

Intraparenchymal myxopapillary ependymoma: case report

OBJECTIVE AND IMPORTANCE

Myxopapillary ependymoma is a histological variant of ependymoma found in the cauda equina region. The most characteristic histological feature of myxopapillary tumors is the abundance of intercellular and perivascular mucin and the arborizing vasculature, which tends to form papillae. Primary intracerebral myxopapillary ependymomas are extremely rare; only three cases have been reported in the previous literature.

CLINICAL PRESENTATION

A 68-year-old man presented with disorientation and dizziness caused by a cystic left frontal intraparenchymal lesion. This proved to be a myxopapillary ependymoma. Similarities to previously reported cases are discussed, as are the findings on magnetic resonance imaging. There is also a literature review of the histological findings, natural history, and outcome of surgically treated myxopapillary ependymoma.

INTERVENTION

The lesion was totally removed. After surgery, the patient was neurologically intact and had an uneventful recovery.

CONCLUSION

This is the fourth reported case of histologically proven primary myxopapillary intracranial ependymoma.

Myxopapillary ependymoma with anaplastic features

A case of myxopapillary ependymoma with anaplastic features in 15-year-old boy is reported. The tumor was located in the intradural space extending to the 12th thoracic to 2nd lumbar vertebral level. It was excised with the accompanying spinal arch of the T12 to L2 vertebra. At operation, the tumor was not attached to the surrounding soft and bony tissues. The tumor, measuring 49 x 19 x 15 mm, was brownish-yellow in color and involved the conus medullaris and filum terminale. Histologically, the tumor was composed of biphasic features of a hypercellular papillary growth area and a hypocellular myxoid area. In the papillary growth area, ependymal rosettes and perivascular pseudorosettes were observed. These findings were consistent with those of a myxopapillary ependymoma, although multiple foci of punctate necrosis within the tumor and proliferation of endothelial cells showing glomeruloid structures were observed. Many mitotic figures were also observed. In addition, the Ki-67 labeling index of tumor cells was 10.1%. These findings are unusual for myxopapillary ependymoma, and therefore, it appeared that the diagnosis of myxopapillary ependymoma with anaplastic features was appropriate.

Lumbosacral ependymomas: a review of the management of intradural and extradural tumors

OBJECT

The goal of this study was to review the management of intra- and extradural ependymomas. Spinal ependymomas most commonly occur as intramedullary tumors throughout the spinal axis. In the lumbosacral region, ependymomas are most commonly associated with the conus medullaris and cauda equina, but can also occur extradurally in the sacrum, presacral tissues, or subcutaneous tissues over the sacrum. These two tumor locations produce different management concerns. Intradural ependymomas, especially those in the lumbosacral region, are now recognized for their potential to spread throughout the central nervous system (CNS), whereas extradural tumors elicit more concern for their association with extraneural metastases.

METHODS

The authors have reviewed the literature regarding both of these distinct tumors and have summarized recommendations for the management of intra- and extradural lumbosacral ependymomas. For both tumors, it appears that gross-total resection is the treatment of choice when feasible. The role of radiation therapy has not been adequately studied for either tumor location, but most clinicians use this modality in patients with subtotal resection of intradural ependymomas, local recurrence, or CNS dissemination. Data supporting the use of radiation therapy for extradural ependymomas are lacking. There does not appear to be a significant role for chemotherapy in either tumor location.

CONCLUSIONS

Despite the risk for local recurrence and CNS dissemination, the prognosis for intradural lumbosacral ependymomas is good, with a greater than 90% 10-year patient survival in most series. The prognosis for extradural ependymomas does not appear to be as good. Much depends on extradural tumor location, however; the outlook is better for dorsal sacral tumors than presacral tumors.

Bifocal myxopapillary ependymoma of the terminal filum: the end of a spectrum? Case report

Myxopapillary ependymomas represent the most frequent type of ependymomas found at the conus medullaris-cauda equina-terminal filum level. They are neuroectodermal tumors mainly observed during the fourth decade of life. Pediatric cases have been rarely described at an age range of 10 to 13 years. Myxopapillary ependymomas are typically solitary tumors involving the terminal filum. Simultaneous discovery of two tumors located both on the terminal filum has been reported once. The pathogenesis of this focal ependymoma located at the same embryological level, on the terminal filum, is uncertain; it may represent one end of a spectrum, the other end being the giant ependymoma of the terminal filum.

Intracranial metastasis of a spinal myxopapillary ependymoma. A case report

A 37-year-old man exhibited a suprasellar tumor which histologically proved to be a myxopapillary ependymoma. Since these gliomas are virtually restricted to the cauda equina region, magnetic resonance imaging (MRI) was performed which revealed multiple spinal tumors. The present case seems to be the first report on spontaneous intracranial seeding of a spinal myxopapillary ependymoma.

Anaplastic ependymomas: clinical features and tumour suppressor gene p53 analysis

We analyzed seven cases of anaplastic ependymoma, focusing on neuro-imaging, histopathology, and mutations of the tumour suppressor gene p53. Five of the seven tumours were supratentorial. All had both cystic and solid components, with fragment calcifications detectable on CT scan. The solid parts of the tumours were imaged as heterogenous hypo- or iso-intense areas with moderate enhancement on T1-weighted magnetic resonance images. Vascularity was not prominent on angiograms except for one case. Histologically, in addition to the WHO criteria, loss of typical cellular architecture, endothelial proliferation, and necrosis were commonly found. A mutation in Exon 5 of the tumour suppressor gene p53 was detected in one anaplastic ependymoma out of five tumours (two benign and three anaplastic ependymomas) examined by PCR-SSPC analysis of genomic DNA followed by direct sequencing. Anaplastic ependymoma typically presents as a calcified cystic tumour in the supratentorial parenchyma or transependyma. Mutations of p53 deserve further investigation to examine their possible role in the oncogenesis and malignant transformation of ependymoma.

Myxopapillary ependymoma. Results of nucleolar organizing region staining

BACKGROUND

Although myxopapillary ependymomas are generally benign with a tendency for slow growth and local recurrence, they are capable of spread within the nervous system and of extraneural metastasis. Histologic features have not been helpful in determining which patients are at risk for recurrence or dissemination, making management decisions difficult.

METHODS

A retrospective review was conducted of 14 cases of myxopapillary ependymoma. The nucleolar organizing region (NOR) staining method was used to determine if this technique was useful in the management of these tumors.

RESULTS

Five patients had total resections of encapsulated lesions, four had total resections of adherent tumors, and four had subtotal resections. Twelve received postoperative radiation therapy. With a mean follow-up of 80 months, 12 patients are well and disease-free. Two patients have had recurrences after surgery and irradiation, leading to death in one and disability in the other. The mean number of NOR per cell in eight specimens ranged from 0.4-1.64. The patient who died with intracranial spread had the highest number of NOR per cell.

CONCLUSIONS

Based on these data and a review of the literature, it is recommended that radiation be delayed until recurrence in tumors that have been totally resected. Local radiation therapy may be indicated in subtotally resected tumors. NOR staining shows promise in predicting the likelihood of spread of tumor. Patients with myxopapillary ependymomas should be followed indefinitely because of the potential for late recurrence, even after aggressive therapy.

Ependymoma of the cauda equina region: diagnosis, treatment, and outcome in 15 patients

New diagnostic imaging techniques make possible a reappraisal of current diagnostic, therapeutic, and management strategies for certain rare lesions of the central nervous system. With this in mind, we have reviewed our experience with ependymoma of the filum terminale and cauda equina region. Fifteen patients with this tumor have been treated since 1955. Typical presentations included pain, lower extremity weakness, and, occasionally, bladder dysfunction. Delays in arriving at the proper diagnosis have been the rule; however, we have noted a substantial increase in the number of these tumors referred to us since the advent of magnetic resonance imaging. Treatment includes surgical resection to the extent consistent with preservation of neurological function; postoperative irradiation appears to be of benefit in controlling recurrence except in those patients whose well-circumscribed tumors have been removed completely. Presence of urinary difficulties at the time of diagnosis is a relatively poor prognostic sign, and a more liberal use of magnetic resonance imaging in cases of persistent or recurrent low back and radicular pain unresponsive to conservative therapy may help to achieve earlier diagnosis. Because of the possibility of late recurrence, prolonged follow-up is mandatory for all patients, and magnetic resonance imaging is the diagnostic tool of choice.

Anaplastic ependymoma of the spinal cord in childhood. A case report

We report a 6-year-old girl with anaplastic ependymoma probably originating in the region of the conus medullaris and probably spreading retrogradely to the region of the interventricular foramen (Monro) through the cerebrospinal fluid (CSF). Since ependymoma of the spinal cord rarely occurs in children, and retrograde spreading is extremely rare, the histological features and mechanism of metastasis of the tumor are discussed.

Histologic characterization of 41 ependymomas with the help of a personal computer

Fourty-one ependymomas were histologically analyzed in relation to patient age and sex and tumor location. A discriminant analysis model using Bayes' formula and a personal computer were employed. Ependymomas situated in the posterior fossa had a higher incidence in children. Ependymoblastomas were all situated above the tentorium and occurred only in young children. We identified three tumor groups on the basis of common histologic characteristics: benign ependymomas, anaplastic ependymomas, and ependymoblastomas. The main features useful for the grouping were the degree of differentiation and anaplasia. Ependymomas from the cauda equina showed histologic characteristics that allowed them to be differentiated from other benign ependymomas. In each group the particular histologic characteristics, age, and location were significant in terms of diagnosis and prognosis. This method of analysis may help to more precisely define ependymomas and may provide pathologists and clinicians with a quantifiable diagnostic tool that may be of help in establishing the appropriate treatment.

Posterior fossa ependymomas in adults

Sixteen patients with posterior fossa ependymomas are presented. This tumour is relatively uncommon in adults and is usually associated with a relatively "benign" course when compared with other posterior fossa glial tumours. The natural history and treatment of these tumours is discussed.