Ependymomas: clinical and pathological aspects

Outcome Analysis in Cases of Spinal Conus Cauda Ependymoma

INTRODUCTION

One half of all central nervous system ependymomas, arise within the spinal canal and about 40% of these arise from filum terminale. The myxopapillary variant of spinal ependymoma almost exclusively occurs in the lumbosacral region and they are histologically designated as Grade I. Long term control is best achieved by gross total removal at the initial operation. There is as yet no consensus on the management of incompletely excised tumour. Opinions regarding radiotherapy are controversial and the indications are empirical.

AIM

In the present study, we investigated the clinical characteristics and long-term outcomes in patients with conus cauda ependymoma that were managed at our center with baseline comparison of our findings with those reported in literature.

MATERIALS AND METHODS

A retrospective analysis of 44 cases of conus cauda ependymoma tumours treated at the Department of Neurosurgery at a tertiary care centre from January 2001 to December 2015 was done. Detailed scrutiny and analysis of the patient's data with respect to the demographic features, clinical findings, investigative procedures, extent of surgical resection, intra and postoperative complications, efficacy of adjuvant therapy, postoperative results and long term follow-up were done.

RESULTS

The analysis was done in 44 patients with conus cauda ependymoma over a period of 15 years. The mean age of presentation was 31 years. Incidence of male predominance was noted. Average duration of presenting features was 10 months. Back pain and motor weakness in the lower limbs were the commonest clinical findings. Total excision of the tumour was possible in 89% cases. Myxopapillary ependymoma was the commonest variant. Radiotherapy was only given in patients with near total to subtotal excision of tumour. Back pain and motor weakness improved in majority of patients after surgery. There is limited role of radiotherapy in cases with total tumour excision.

CONCLUSION

Conus cauda ependymomas are relatively benign tumours. The long term prognosis is excellent with respect to recurrence and functional outcome in cases with complete tumour excision. Early diagnosis and surgery will prevent occurrence of permanent neurological deficits. Radiotherapy can be given in cases of subtotal excision but there is limited role of radiotherapy in cases with total tumour excision.

Magnetic resonance imaging findings of extraventricular anaplastic ependymoma: A report of 11 cases

Anaplastic ependymomas are rare malignant tumors of the central nervous system. Few studies are available regarding their neuroradiological characteristics. The present study aimed to retrospectively review a series of patients with extraventricular anaplastic ependymoma and to analyze the magnetic resonance imaging (MRI) characteristics to distinguish anaplastic ependymoma from other intracranial tumors. The clinical and pathological images of 11 patients who presented with histologically proven anaplastic ependymoma at Nanfang Hospital (Southern Medical University, Guangzhou, Guangdong, China) between September 2004 and March 2015 were retrospectively reviewed. MRI scans were obtained in all 11 cases. Computed tomography scans were obtained in only 3 cases. In total, 8 tumors were located at the supratentorial parenchyma, and 3 tumors were derived from the cerebellar hemisphere. Images displayed quasi-circular (4/11), irregularly-lobulated (7/11) variable-intensity masses. The masses presented with cysts or necrosis (8/11), hemorrhage (7/11), marked (9/11) or mild (2/11) enhancement, and moderate (4/11), mild (3/11) or absent (4/11) peritumoral edema. The tumors were also frequently closely associated with the lateral ventricle (6/11). Tumors appeared isointense to hypointense on T1-weighted imaging (T1WI) and heterogeneously hyperintense or hypointense on T2WI, demonstrating wreath-like and ring-like characteristics, with intratumoral nodules (3/11) or marked flake-like inhomogeneous (6/11) enhancement on post-contrast MRI. Only 2 solid lesions showed mild enhancement (2/11). Although the MRI features of the extraventricular anaplastic ependymomas varied and were non-specific, these characteristic MRI findings, combined with the locations of the lesions, the age of onset and the short disease course, could be useful in differentiating anaplastic ependymomas from other intracranial neoplasms in the future.

Spinal ependymoma with regional metastasis at presentation

BACKGROUND

Ependymomas are the most common glial neoplasms in the spinal cord. However, spinal cord ependymomas presenting with regional dissemination along the neuroaxis are rare, with a yet undetermined standard of care. We retrospectively evaluated the management and outcomes of patients who were diagnosed with spinal ependymoma with regional metastases at presentation (SERMP).

METHODS

Between 2002 and 2012, 16 patients with regionally metastatic spinal ependymomas were diagnosed and treated. The patients were retrospectively divided into two groups according to tumor grading and histological features. Nine patients were diagnosed with myxopapillary ependymomas (MPE), and seven patients were diagnosed with other low-grade ependymomas.

RESULTS

With a median follow-up of 46.4 months, 13 out of 16 patients had no postsurgical recurrence/progression of the disease. In three patients, the disease recurred/progressed, leading to death in one patient. There was no correlation between gross total removal (GTR) of the main tumor, or resection of the main lesion and the metastatic foci and increased progression free survival in patients of the MPE group. There was an advantage for patients diagnosed with other low-grade ependymomas. Adjuvant radiotherapy did not prove beneficial.

CONCLUSIONS

SERMP has a relatively benign course. Achieving GTR of both the main lesion and the metastases is preferable, but should not be achieved at any cost, especially in MPE interfering with the conus medullaris. The benefit of adjuvant radiotherapy remains unproven.

Anaplastic ependymoma simulating glioblastoma in the cerebrum of an adult

A case of anaplastic ependymoma of the cerebral hemisphere in which the histopathological features closely simulated those of glioblastoma is reported. The patient was a 72-year-old woman with a large, well-demarcated tumor in the left temporal lobe. The tumor was totally extirpated, but recurred 18 months later, and the patient died after 4 months. The extirpated tumor was well circumscribed from the surrounding brain tissue and consisted of a sheet-like, dense proliferation of atypical, short spindle or polygonal cells. Extensive geographic necrosis with nuclear pseudopalisading was seen. Although perivascular pseudorosettes were observed in many areas, true ependymal rosettes were absent. Immunohistochemistry for glial fibrillary acidic protein and epithelial membrane antigen and ultrastructural study confirmed the ependymal nature of tumor cells. The histopathological spectrum of anaplastic ependymoma is very wide and reflects the basically dual characteristics of ependymal cells: epithelial and glial phenotypes. The present case indicates that some anaplastic ependymomas strongly express the glial phenotype and also show remarkable anaplastic cytological features, thus closely simulating glioblastoma. The diagnostic criteria for anaplastic ependymoma, and the nosological position of highly anaplastic ependymoma and its possible clinical implications, are briefly discussed.

Supratentorial clear cell ependymoma mimicking oligodendroglioma : case report and review of the literature

Clear cell ependymomas (CCEs) are rare variants of ependymomas. Tumors show anaplastic histological features and behave as an aggressive manner. CCEs have a predilection for extraneural metastases and early recurrence, and they demonstrate characteristic radiographic features. These tumors should be radiologically and pathologically differentiated from oligodendrogliomas. On microscopic examination, CCEs are composed of sheets of cells and resemble oligodendroglioma. However, upon closer examination, the nature of CCEs can be detected earlier, resulting in prompt treatment of the tumor. Although we report only one case, we emphasize the importance of early diagnosis and treatment. Future description of more cases of these rare cancers is necessary to aid in their diagnosis and treatment.

Survival following treatment for intracranial ependymoma: a review

The actual definition of survival rates following treatment for intracranial ependymomas is substantially influenced by the strict interaction among different factors. Age, location, and grading, for example, act together, negatively influencing the prognosis of younger children also invariably influenced by the more demanding role of surgery and the still limited use, up to recently, of radiotherapy under 3 years of age. In the same direction, the worse prognosis in most series of infratentorial ependymomas if compared with their supratentorial counterpart should be cautiously considered, midline posterior fossa tumors having completely different implications from those originating or predominantly extending to the cerebellopontine angle, where the extent of surgery has more invariably to compare with patients' quality of life. New radiotherapic regimens and their applications in infancy are promisingly demonstrating an improvement of present prognostic criteria, with the limit of still insufficient information on their long-term secondary effects. Similarly, molecular biology research studies, though still in their preclinical stage, are prompting to change the concept of a substantially chemoresistant tumor helping to stratify these lesions with the final aim of targeted pharmacological therapies. In the present review paper, we investigated singularly the role that the more commonly considered prognostic factors have had in the literature on survival of children affected by intracranial ependymomas, trying to elucidate their cumulative effect on the actual knowledge of this issue.

Surgical considerations in fourth ventricular ependymoma with the transcerebellomedullary fissure approach in focus

INTRODUCTION

Within the existing consensus for the best management of pediatric infratentorial ependymomas (PIE), surgery is the most important stage, where complete removal should be the perfect aim, before complementing it with chemo- or radiotherapy. That, however, remains a challenge even for the most skillful surgeons because of the vicinity of important brainstem and cranial nerve structures involved and is particularly difficult in lateral extensions.

MATERIALS AND METHODS

The paper analyzes the current trends of PIE treatment with emphasis on resection difficulties created by lateral extensions. Anatomical analysis and clinical application of the cerebellomedullary fissure dissection has created specific approaches, providing safe route to the lateral recess and cerebellopontine area by dividing safely tenia and tonsils and biventer lobes retraction.

DISCUSSION AND CONCLUSION

Bilateral and unilateral approaches have been developed. This approach prevents the damage of transvermian access and the resulting cerebellar mutism in some cases. Indications, technique and benefits of transcerebellomedullary fissure types of approaches are discussed.

The history of ependymoma management

INTRODUCTION

The ependymomas are relatively not a common tumor. However, most clinicians agree that the radical removal of the tumor is the most important prognostic factor.

MORBIDITY OF TREATMENT

Tumor removal was not sufficient before the era of magnetic resonance imaging (MRI) and resulted in a considerable operative morbidity and mortality. As the microneurosurgical techniques and microsurgical anatomy become popular and the MRI provide more detailed anatomical information preoperatively, radical removal of this complex and complicated tumor can be more feasible. In childhood ependymoma, the treatment-related morbidity and mortality can be the special issues, which can modify the policy of management safe tumor removal and minimal adjuvant treatment, which are extremely important.

RADIATION THERAPY

Radiation treatment has been the option for disseminated disease and residual tumor. With the advancement of detailed MR anatomical information, safer and more delicate radiation becomes possible with newer radiation modalities, three-dimensional conformal radiotherapy, intensity modulating radiotherapy, and tomotherapy.

PROGNOSTIC FACTORS

Although many clinicians believe that the ependymomas are inheritably chemoresistant, the new targets for the treatment are under investigation or clinically tried. Also, the genetic alterations of ependymoma are developing and might be a promising target.

CONCLUSION

The surgical techniques and assistant modalities for tumor removal are still advancing. So, the outcome of ependymoma is still improving. Unfortunately, newer treatment modalities, such as new chemotherapeutic agent and gene modification agent, are still not promising. The history of ependymoma management is still in progress.

Incidence patterns for ependymoma: a surveillance, epidemiology, and end results study

OBJECT

Previous small studies disagree about which clinical risk factors influence ependymoma incidence. The authors analyzed a large, population-based cancer registry to examine the relationship of incidence to patient age, sex, race, and tumor location, and to determine incidence trends over the past 3 decades.

METHODS

Data were obtained from the Surveillance, Epidemiology, and End Results (SEER-9) study, which was conducted from 1973 to 2003. Histological codes were used to define ependymomas. Age-adjusted incidence rates were compared by confidence intervals in the SEER*Stat 6.2 program. Multiplicative Poisson regression and Joinpoint analysis were used to determine annual percentage change and to look for sharp changes in incidence, respectively.

RESULTS

From the SEER database, 1402 patients were identified. The incidence rate per 100,000 person-years was significantly higher in male than in female patients (males 0.227 +/- 0.029, females 0.166 +/- 0.03). For children, the age at diagnosis differed significantly by tumor location, with the mean age for patients with infratentorial tumors calculated as 5 +/- 0.4 years; for supratentorial tumors it was 7.77 +/- 0.6 years, and for spinal lesions it was 12.16 +/- 0.8 years. (Values are expressed as the mean +/- standard error [SE].) Adults showed no difference in the mean age of incidence by location, although most tumors in this age group were spinal. Between 1973 and 2003, the incidence increased significantly among adults but not among children, and there were no sharp changes at any single year, both before and after age adjustment.

CONCLUSIONS

Males have a higher incidence of ependymoma than do females. A biological explanation remains elusive. Ependymoma occurs within the CNS at distinct locations at different ages, consistent with hypotheses postulating distinct populations of radial glial stem cells within the CNS. Ependymoma incidence appears to have increased over the past 3 decades, but only in adults.

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.

Identification of relevant prognostic histopathologic features in 69 intracranial ependymomas, excluding myxopapillary ependymomas and subependymomas

BACKGROUND

The results of attempts to identify histopathologic parameters that contribute to the clinical outcome of patients with ependymomas have been controversial. This may be due to the relative rareness of ependymomas. Furthermore, in many investigations, myxopapillary ependymomas and subependymomas were included and may have confounded results, because those tumors should be considered clinicopathologic entities distinct from the other ependymomas.

METHODS

In this retrospective study, the influence of the histologic subtype of ependymoma and of individual histologic features on the outcome of 69 patients with ependymomas was investigated. Myxopapillary ependymomas, subependymomas, and ependymomas with spinal localizations were excluded from the analysis. The ependymomas were subdivided into cellular, papillary, clear cell, and tanycytic subtypes. The study extended over a period of 30 years.

RESULTS

No differences in clinical outcome between the four histologic subtypes of ependymomas were revealed. Neither tumor localization (either infratentorial or supratentorial), patient age, nor gender affected survival. The survival of patients who underwent complete tumor resection differed significantly from that of patients who underwent partial resection. In univariate analysis, the features of nuclear atypia, the mitotic index, and the MIB-1 labeling index (LI) significantly influenced survival. With regard to survival, the presence of microcysts, blood vessel density, and the feature of vascular hyalinization demonstrated a trend but did not reach significance. In multivariate analysis, only the mitotic index and the MIB-1 LI were identified as factors with independent prognostic significance (P = 0.027 and P = 0.023, respectively). Both proliferation indices were correlated strongly with each other.

CONCLUSIONS

The results of the univariate analysis indicated that, for patients with intracranial ependymoma, nuclear atypia, the mitotic index, and the MIB-1 LI significantly influenced survival. In the multivariate analysis, the mitotic index and the MIB-1 LI were the only features that had independent prognostic significance. Because both showed strong correlations, only one of them should be included in a grading scheme for intracranial ependymomas.

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.

Anaplastic ependymoma of the fourth ventricle causing obstrictive hydrocephalus

SummaryEpendymomas are relatively uncommon and present with a spectrum of biological and clinical characteristics that make specific recommendations regarding their treatment difficult and assignment of prognostic factors controversial. The case of fourth ventricular anaplastic epednymoma in a four-year-old child is reported in which the initial presentation was deterioration of the level of consciousness secondary to acute obstructive hydrocephalus. An initial insertion of a ventriculo-peritoneal shunt (V-P) to deal with the acute intracranial hypertension was done. Subsequently, sub-occipital craniectomy and sub-total resection of the tumour were performed successfully. Post-operative radiotherapy was also undertaken on the patient. The pertinent literature is reviewed. At one year follow up our patient had clinically improved with no signs of recurrence. The most important prognostic factors are tumour grade and the presence of residual tumour on post operative imaging studies. A median survival of 31 months is noted in children with infratentorial ependymomas and one year survival is quoted as 81%.

Intraventricular gliomas

Gliomas are the most common primary brain tumor in adults, and those within or relating to the ventricular surface represent a less common but important subcategory. The most common intraventricular gliomas include ependymomas, SEs, and SEGAs. Other less common varieties have been reported, including chordoid gliomas, glioblastoma multiforme, and mixed glial-neuronal tumors. Each type of intraventricular glioma is associated with its own unique constellation of epidemiologic, clinical, radiologic, and pathologic defining characteristics. Each tumor type has its own management considerations and nuances with unique prognostic indicators and outcomes. The outcome for certain intraventricular gliomas (especially ependymomas) remains relatively poor. Future advancements in surgical technique are likely to have only a modest impact on improvement of outcome. Translational research aiming to advance the knowledge of tumor biology into new targeted cellular and molecular therapies holds tremendous promise to improve the overall outcome. Additionally, more thorough delineation of prognostic factors as well as modifications and refinements to radiation and chemotherapy may help to improve the still significantly poor outcomes for patients harboring these lesions. Future cooperative intra- and interinstitutional efforts between scientists and clinicians will hopefully culminate in an improved outlook and eventual cure for patients with gliomas.

9p21 and 13q14 dosages in ependymomas. A clinicopathologic study of 101 cases

Ependymomas are glial neoplasms whose clinical behavior is difficult to predict based on histology alone. Recently, a comparative genomic hybridization study identified frequent chromosome 9p and 13q losses in anaplastic ependymomas, suggesting that p16 and RB alterations may be involved in tumor progression. In order to test this hypothesis further, 101 myxopapillary, conventional, and anaplastic ependymomas (51 spinal and 50 intracranial tumors) were tested for RB and p16 deletions using fluorescence in situ hybridization. Clinical follow-up, ranging from 2 to 198 months (median 46 months), was obtained in 90 cases (91%). RB and p16 deletions were seen in 22 of 92 (24%) and 22 of 89 (25%) informative cases, respectively. Polysomies were more frequent in the grade I and II spinal tumors, consistent with prior reports of increased aneuploidy in such cases. No significant genetic associations were seen with tumor grade, recurrence, or death, suggesting that 9p and 13q deletions do not play a prominent role in the malignant progression of ependymomas, as has been implicated in other glioma subtypes.

Parenchymal anaplastic ependymoma with intratumoral hemorrhage: a case report

We report an unusual case of a 56-year-old woman with a supratentorial anaplastic ependymoma localized in the parenchyma without continuity with the ventricular system and brain surface. The patient presented with vertigo, and a calcified mass was detected in the left temporal parenchyma. Five years later, she had seizure of the right extremities. Computed tomographic scanning and magnetic resonance imaging revealed an enhanced mass with an intratumoral hemorrhage adjacent to the calcified mass. Subtotal removal of the tumor was performed. The histological analysis revealed that the tumor was an anaplastic ependymoma. After focal radiation therapy (50 Gy), the outcome was favorable, although the residual lesion was still seen on the images. Ependymomas usually arise from the cells lining the ventricular system and the central canal of the spinal cord. We discuss the summary of published cases of supratentorial ectopic ependymoma since the first case in 1995.

En-plaque ventricular ependymoma

An extremely unusual case demonstrating rare behaviour of an ependymoma is presented. The tumour spread in an en-plaque fashion and involved the ependymal lining of the entire ventricular system. The patient, a 56-year-old male, presented with symptoms of raised intracranial pressure and truncal ataxia. The management issues are analyzed on the basis of a brief literature survey.

Brain surface ependymoma with repeated episodes of intratumoral hemorrhage--case report

A 70-year-old woman presented with a rare brain surface ependymoma with repeated intratumoral hemorrhage. She was admitted with progressive dementia. Two years earlier, a diagnosis of subcortical hematoma in the right frontal lobe had been made following a fall. On admission, magnetic resonance imaging showed a huge right frontal mass lesion with multiple hemorrhagic cysts. She underwent gross total resection. The tumor was located on the surface of the frontal lobe, and was sharply demarcated from the surrounding brain tissue with no attachment to the ventricular wall. The histological features were consistent with an ependymoma forming perivascular pseudorosettes. Immunohistochemistry showed positive staining for glial fibrillary acidic protein. Electron microscopy showed microvilli and zonula adherens. This case demonstrates the natural course of malignant progression of ectopic ependymomas. Ependymoma should be included in the differential diagnosis of tumors associated with repeated subcortical hematomas, even if located on the brain surface and distant from ventricles.

Intracranial and spinal ependymomas: review of MR images in 61 patients

OBJECTIVE

To compare the age distribution and characteristic MR imaging findings of ependymoma for each typical location within the neuraxis.

MATERIALS AND METHODS

During a recent eleven-year period, MR images of 61 patients with histologically proven ependymomas were obtained and retrospectively reviewed in terms of incidence, peak age, location, size, signal intensity, the presence or absence of cyst and hemorrhage, enhancement pattern, and other associated findings.

RESULTS

Among the 61 patients, tumor location was spinal in 35 (57%), infrartentorial in 19 (31%), and supratentorial in seven (12%). In four of these seven, the tumor was located in brain parenchyma, and in most cases developed between the third and fifth decade. Approximately half of the infratentorial tumors occurred during the first decade. The signal intensity of ependymomas was nonspecific, regardless of their location. A cystic component was seen in 71% (5/7) of supratentorial, 74% (14/19) of infratentorial, and 14% (5/35) of spinal cord tumors. Forty- nine percent (17/35) of those in the spinal cord were associated with rostral and/or caudal reactive cysts. Intratumoral hemorrhage occurred in 57% (4/7) of supratentorial, 32% (6/19) of infratentorial, and 9% (3/35) of spinal cord tumors. In 17% (6/35) of spinal ependymomas, a curvilinear low T2 signal, suggesting marginal hemorrhage, was seen at the upper and/or lower margins of the tumors. Peritumoral edema occurred in 57% (4/7) of supratentorial, 6% (3/19) of infratentorial and 23% (8/35) of spinal cord tumors. Seventy-two percent (5/7) of supratentorial and 95% (18/19) of infratentorial tumors showed heterogeneous enhancement, while in 50% (17/34) of spinal cord tumors, enhancement was homogeneous.

CONCLUSION

Even though the MR imaging findings of ependymomas vary and are nonspecific, awareness of these findings, and of tumor distribution according to age, is helpful and increases the likelihood of correct preoperative clinical diagnosis.

Proliferation- and apoptosis-related proteins in intracranial ependymomas: an immunohistochemical analysis

As the value of grading of ependymomas is currently debated we studied the expression of proliferation- and apoptosis-related proteins in these tumors as these mechanisms both are suggested to be important in tumor growth. We characterized the immunohistochemical expression of p53, Mdm2, Bcl-2, and Bax in 51 intracranial ependymomas. We also assessed the apoptosis- and proliferation-index, measured by MIB-1, PCNA-immunohistochemistry, and analyzed the clinical parameters. Of all used antibodies, the correlation with survival and the correlation among ordered categories was assessed. None of the analyzed immunohistochemical variables were significantly correlated with tumor grade. On the other hand, PCNA, MIB-1, and p53 were significantly related to the survival of the patient. In multivariate analysis, p53 was the only independent predictive variable (p = 0.0132).

CONCLUSION

The strongest predictors of survival in univariate analysis were the expression of PCNA, MIB-1 and p53. In multivariate analysis a p53 expression > 1% showed to be significantly related with a worse survival. The predicting value of p53 expression has to be confirmed by others before solid conclusions can be made. Apoptosis seems not to be an important mechanism in tumor growth in ependymomas. The expression of Mdm2, Bcl-2, and Bax were not related to survival.

Surveillance neuroimaging in childhood intracranial ependymoma: how effective, how often, and for how long?

OBJECT

The authors examined images obtained in 52 children with intracranial ependymomas to determine risk factors for tumor recurrence and to assess the impact of surveillance imaging on patient outcome.

METHODS

Data obtained in all children with intracranial ependymomas were prospectively entered into a database from January 1987 to June 2000. The imaging and clinical details in all patients were reviewed. Fifty-two children with histologically proven intracranial ependymomas were treated at the authors' institution; recurrences developed in 28 (54%) of them, with a median time from surgery to first recurrence of 14.5 months (range 3-65 months). Of these tumor recurrences, 43% were asymptomatic and were noted on surveillance imaging. Seventeen children died, all of whom had recurrences. Incomplete excision of the primary tumor was significantly associated with reduced time to recurrence (p = 0.0144) and time to death (p = 0.0472). The age of the patient, location of the primary tumor, histological findings, and the presence or absence of spinal metastases on preoperative imaging were not significantly associated with outcome. The risk of death at any given time was 12-fold greater in patients in whom a recurrence was identified due to symptoms rather than on surveillance images (p = 0.016).

CONCLUSIONS

Recurrent childhood ependymoma has a poor prognosis. The extent of the initial local tumor resection is the factor most closely associated with outcome. Surveillance imaging reveals a substantial number of asymptomatic recurrences, and survival appears to be improved in these patients compared with those identified by symptoms. The improvement in survival is thought to be greater than that expected just from earlier diagnosis.

Combined postoperative irradiation and chemotherapy for anaplastic ependymomas in childhood: results of the German prospective trials HIT 88/89 and HIT 91

PURPOSE

To evaluate the outcome in children with anaplastic ependymomas after surgery, irradiation, and chemotherapy; and to identify prognostic factors for survival.

METHODS AND MATERIALS

Fifty-five children (n = 27 girls, 28 boys; median age at diagnosis, 6.2 years) with newly diagnosed anaplastic ependymomas were treated in the multicenter, prospective trials HIT 88/89 and HIT 91. Macroscopic complete resection was achieved in 28 patients; 27 patients underwent incomplete resection. All patients received chemotherapy before (n = 40) or after irradiation (n = 15). The irradiation volume encompassed either the neuraxis followed by a boost to the primary tumor site (n = 40) or the tumor region only (n = 13). No radiotherapy was administered in two patients.

RESULTS

Median follow-up was 38 months. The overall survival rate at 3 years after surgery was 75.6%. Disease progression occurred in 25 children with local progression occurring in 20. The median time to disease progression was 45 months. The only significant prognostic factor was the extent of resection (estimated progression-free survival [EPFS] after 3 years was 83.3% after complete resection and 38.5% after incomplete resection) and the presence of metastases at the time of diagnosis (0% vs. 65.8% 3-year EPFS in localized tumors). Age, sex, tumor site, mode of chemotherapy, and irradiation volume did not influence survival.

CONCLUSIONS

Treatment centers should be meticulous about surgery and diagnostic workup. Because the primary tumor region is the predominant site of failure it is important to intensify local treatment. Dose escalation by hyperfractionation or stereotactic radiotherapy might be a promising approach in macroscopically residual disease. The role of adjuvant chemotherapy requires further study.

[Ependymomas: Clinical, epidemiological and clinico-pathological findings of 22 cases]

Ependymomas are composed of neoplastic ependymal cells, affecting mainly children and young adults. We report the clinical and pathological findings of 22 cases of ependymomas. Fourteen patients were males and 8 were females. The ages ranged between 1 and 58 years, with a mean of 24.63 years. The symptoms reflected the growth and topography of the tumours; muscle weakness (59.1%), gait disorders (36.3%), sensitive disorders (36.3%), hyperreflexia and intracranial hypertension syndrome were the most frequent symptoms. Ten tumours affected the medulla, 7 the cerebral hemispheres, 2 the cerebral ventricles and 1 brain stem. Seven patients were submitted total resection of the tumor, from which one received adjuvant radiotherapy. 15 other patients were submitted to partial resection; from which 4 received adjuvant radiotherapy, 3 adjuvant chemotherapy and 1 chemotherapy and radiotherapy. The recurrence rate was 18.2%. These results are similar with the literature and may contribute to further understanding the biological behavior of these tumours.

Supratentorial ependymomas in adult patients

OBJECTIVE

Ependymomas arise from different areas in the neuraxis and have variable outcomes that depend on tumor location and patient age at the time of presentation. The predictive value of histology for these tumors is unresolved. We report a series of adult patients with supratentorial ependymomas to characterize the roles of surgery, histology, ploidy, and proliferation index in tumor control.

METHODS

Fourteen of the 23 supratentorial ependymomas were in the region of the third ventricle and the remainder were located in the hemispheres. Resections were gross total in 12 patients, subtotal in 8, and biopsy in 3. A single pathologist reviewed all slides and quantitated the deoxyribonucleic acid. The mean follow-up duration was 95 months (+/-75 mo).

RESULTS

All of the malignant ependymomas were hemispheric (n = 4). Mortality occurred only in patients with third ventricular tumors; two patients died as a result of surgical complications and three as a result of tumor progression. Kaplan-Meier estimates of 5- and 10-year survival rates were 100% for hemispheric and 72.5% for third ventricular tumors (62.5% including the two perioperative deaths). The median time to recurrence was 53 months, with a 10-year progression-free survival rate of 27%. Univariate analysis revealed that recurrence was associated with malignant histology, including mitoses, cellularity, and aneuploidy. For nonmalignant ependymomas, recurrence was associated with subtotal resection and metastases. S-phase fraction did not correlate with recurrence. Only malignant histology correlated with recurrence on multivariate analysis.

CONCLUSION

Although the numbers are too small to draw any definite conclusions, treatment of ependymomas that arise in the supratentorial compartment in adult patients results in excellent outcomes despite frequent recurrences. Association with the third ventricle and metastases seem to have a negative impact on survival, whereas malignant histology, subtotal resection, and metastases may be predictors of recurrence.

Postoperative radiotherapy of spinal and intracranial ependymomas: analysis of prognostic factors

PURPOSE

Postoperative radiation therapy adds significantly to disease control and survival of patients with ependymoma. However, much controversy exists about the radiation treatment policy. We report the long-term results of a cohort of 56 patients with primary intracranial and spinal ependymomas. Special effort has been taken to define prognostic indicators as a basis for future treatment strategies.

PATIENTS AND METHODS

Between November 1963 and May 1995, 56 patients with histological proven ependymoma were referred to our clinic for further treatment following surgery. Thirty patients had a high grading tumor and 26 had low grade tumors. Seventeen patients had supratentorial tumors and 24 had infratentorial tumors. Fifteen patients suffered from localized spinal tumors.

RESULTS

The mean survival time for all patients was 77 months. Five- and 10-year survival probabilities were 60 and 51%, respectively. The mean progression free survival (PFS) probability for all patients was 67 months with corresponding 5- and 10-year PFS probabilities of 53 and 39%, respectively. On univariate analysis initial performance status, age and tumor grade were significant for survival probability. Concerning PFS radiation dose was significant with improved survival with doses > 45 Gy. On multivariate analysis, tumor grade and initial performance status proved to be the only independent prognostic factors.

CONCLUSIONS

Tumor grade, age, initial performance status and radiation dose are significant factors for the clinical course of patients and have to be taken into account for the urgently needed prospective trials.

Clear cell ependymoma: a mimic of oligodendroglioma: clinicopathologic and ultrastructural considerations

Although clear cells resembling oligodendrocytes are known to occur in ependymomas, tumors composed primarily of such cells, i.e., clear cell ependymoma (CCE), are rare. Herein we characterize the clinicopathologic features of eight examples of CCE encountered at Mayo Clinic from 1983 to 1996. The tumors occurred in patients 3-31 years of age and presented as well-demarcated, deeply situated, contrast-enhancing masses, all of which were supratentorial. All but one case lacked classic light microscopic features of ependymoma. Although nearly all were immunoreactive for glial fibrillary acidic protein, it was electron microscopy that showed the diagnostic hallmarks of ependymoma, including complex intercellular junctions, surface microvilli and cilia, and microrosette formation, thus underscoring the importance of electron microscopy in the diagnosis of clear cell ependymomas. The differential diagnosis of CCE includes not only oligodendroglioma, but central neurocytoma and glioneurocytoma. Unlike oligodendrogliomas, CCEs are characterized by their sharp circumscription, hypervascularity as reflected in contrast enhancement on computed tomography and magnetic resonance imaging, their noninfiltrative pattern of growth that displaces parenchyma, and the occasional formation of vague perivascular pseudorosettes. Unlike central neurocytomas and glioneurocytomas, CCE lack secretory granules, vesicles, and synapses by electron microscopy and neuroendocrine markers by immunocytochemistry. In summary, the diagnosis of CCE requires neuroimaging, histologic, and ultrastructural correlation. The latter is essential in a limited biopsy. Ultrastructural studies also play a role in identifying glioneurocytomas. CCEs behave like more ordinary ependymomas. The importance of their recognition is the avoidance of alternative diagnoses and inappropriate therapies.

Second-look surgery for incompletely resected fourth ventricle ependymomas: technical case report

OBJECTIVE AND IMPORTANCE

The prognosis for patients with ependymomas is related to the adequacy of surgical clearance. It is, however, often not possible to obtain a macroscopically complete resection of tumors arising in the posterior fossa. This may be because of the involvement of structures, the sacrifice of which would result in unacceptable morbidity, or because of metastatic lesions at diagnosis. For those patients in whom initial surgery was incomplete, elective second-look surgery may allow more complete clearance of tumor.

INTERVENTION

We have performed second-look surgery for fourth ventricle ependymomas in five patients: two women, aged 26 and 27 years, and three male patients, aged 4 months, 19 months, and 18 years. The 19-month-old male patient underwent early second-look surgery without receiving any interim chemotherapy. Second-look surgery on the other four patients was performed after they had received chemotherapy. No additional major morbidity was associated with the subsequent surgery, which achieved macroscopically complete clearances in four of the five patients. Three of four patients who underwent macroscopically complete resections were well, without clinical or radiological evidence of recurrent tumor, at 23, 25, and 34 months after their second operations. The 10-month-old patient who underwent early second-look complete resection relapsed locally at 33 months after surgery. Complete resection was not possible in one patient who had progressive tumor 8 months after second-look surgery.

CONCLUSION

For patients in whom complete excision of fourth ventricle ependymomas is not possible at initial surgery, second-look procedures may enable macroscopic clearance to be achieved with little morbidity. A larger study is needed to evaluate this approach to treatment.

Spinal ependymomas--the value of postoperative radiotherapy for residual disease control

Spinal ependymomas are rare intramedullary tumours, usually with a benign biological nature. They have, however, a known potential for recurrence and metastatic spread through the CSF pathways. Traditionally, radiotherapy has been employed as an adjuvant to surgery. Recently, however, this view has been increasingly questioned. Thirty-eight adult patients operated in the West Midlands between 1956 and 1994 were reviewed. Mean age at presentation was 37.8 years. Of all tumours 45% (17) were situated in the conus/cauda equina region, 26% (10) in the thoracic and 29% (11) in the cervical region. All patients underwent surgery as primary treatment. Postoperative mortality was 2.6% (one patient). Complete macroscopic excision of their tumours was performed in 14 patients; of these three received postoperative radiotherapy. Subtotal excision was performed in 18 patients, seven receiving adjuvant radiotherapy. Decompressive laminectomy and biopsy was performed in five patients with either no radiotherapy in one, radiotherapy in three or radiotherapy and chemotherapy in one. The overall survival rate was 87% at 5 years and 73% at 10 years for the whole series. In patients treated after the 1970s, the cumulative 10-year survival was 95%. Patients over the age of 40 years at diagnosis had a 10-year survival of 61% compared to 78% of those under the age of 40. Intramedullary tumours had a worse outcome with 68% survival at 10 years, compared to 89% of tumours at the cauda equina. Total excision carried 86% survival, subtotal excision 80% and biopsy only 25% at 10 years. In those patients treated by administration of postoperative radiotherapy the 10-year survival was 48%, compared to 96% in those in whom radiotherapy was not given postoperatively. Analysis of the recurrence and survival rates demonstrated that radiotherapy did not confer any significant protection against recurrence or disease progression. Whilst complete excision offers the maximal potential for cure, an expectant policy with possible repeat surgery may be appropriate when total excision is not achieved. The main conclusion to be drawn is that a randomized controlled trial of the value of adjuvant radiotherapy is greatly needed.

Disseminated ependymomas of the central nervous system

Ependymomas are rare central nervous system (CNS) neoplasms that occasionally disseminate along the neuraxis or to extraneural sites. Definitive criteria predictive of dissemination have yet to be determined. One hundred forty patients with CNS ependymoma (88 primary spinal and 52 primary intracranial tumors) were surgically treated by the senior author (F.J.E.) between 1986 and 1994. Sixteen patients (11.4%) demonstrated tumor dissemination. The disseminated group consisted of 11 (12.5%) of 88 primary spinal and five (9.6%) of 52 primary intracranial ependymomas. The authors retrospectively reviewed the patients with CNS ependymoma and have identified several characteristics associated with dissemination from the primary tumor site. The mean time from diagnosis to dissemination was 6.8 years. The patients with disseminated disease were younger (16.8 vs. 28.3 years old, p = 0.02), had fewer gross-total resections (29% vs. 68%, p = 0.015), and had tumors with higher proliferative indices (MIB-1 staining, 13.14% vs. 2.06%, p = 0.02). High-grade tumors had a mean proliferation index of 21%, versus 2.4% and 1.6% for myxopapillary and low-grade tumors, respectively (p = 0.0003). In contrast to previous studies, tumor histology was the most significant variable for time to dissemination as determined by multivariate analysis (p = 0.008). Myxopapillary and high-grade tumors were 3.6 and 5.6 times more likely to have a shorter time to dissemination than low-grade tumors. In addition, dissemination is associated with a worse prognosis. At follow-up review, 31% of patients with disseminated disease had died compared to 7% of patients without dissemination (p = 0.04). It is concluded that younger patients with subtotal resections, myxopapillary or high-grade histology, and tumors with high proliferative indices are at substantial risk for the development of disseminated disease during their clinical course.

Supratentorial ectopic ependymoma

BACKGROUND

Ependymomas usually arise from the ventricular surface.

METHODS

We report an 11-year-old female who presented with a supratentorial ectopic ependymoma.

RESULTS

The patient presented with a two-month-history of progressive headache, nausea and vomiting. Examination revealed papilledema, horizontal nystagmus, diplopia on upward gaze, and right pronator drift. CT scan showed an enhancing left precentral subcortical lesion measuring 3 cm in diameter with associated edema and mass effect. Its medial border was located 3 cm from the ependymal surface of the ventricle. A firm tumour was dissected from the centrum semiovale white matter, and removed in toto as confirmed on MRI. Pathological examination revealed histological, immuno-histochemical and electron microscopic features consistent with an ependymoma. Spine MRI and bone marrow aspirate, as well as lumbar puncture of cytology failed to show any dissemination.

CONCLUSION

From the literature review, this represents an exceptional ependymoma located at the distance from the ventricular system or cisterns. Different pathogenic alternatives are discussed.

Fourth ventricle ependymomas. A study of 20 cases with survival analysis

Twenty patients with fourth ventricle ependymoma were treated surgically at our Neurosurgery Division between January 1976 and December 1990. Ependymoblastomas and mixed gliomas operated on in the same period have not been considered. A statistical analysis of our cases and a review of the largest published series show that favourable prognostic factors are: age over 16, post-operative radiotherapy to the posterior cranial fossa and a good Karnofsky performance status (KPS) after operation. The 5-year survival rate of patients under 16 was 20%, in comparison with 60% of adults (p = 0.013). Post-operative radiotherapy to the posterior cranial fossa improved the survival markedly (5-year survival rate 68%, versus 18% without treatment; p = 0.011). The differences of survival are also significant according to a multivariate analysis (p = 0.038). Patients with a post-operative KPS over 70 had a 5-year survival rate of 61% as against 17% of the group with a worse clinical condition (p = 0.032); the multivariate analysis confirmed also that this difference was significant (p = 0.046). Pre-operative symptoms and signs, and KPS, histological grade and extent of surgical removal seem to influence the prognosis, even if the differences of survival are not statistically significant. The statistical relevance of postoperative residual tumour on CT or MRI was brought out on multivariate analysis (p = 0.044).

Ependymomas of the third ventricle

Third ventricular ependymomas are rare tumors that have not been specifically examined. Four cases of these tumors are reported. The presenting symptoms included headache, ataxia, vertigo, and Parinaud's syndrome. All the patients underwent computed tomographic scanning and cerebral angiography, followed by craniotomy and microsurgical resection of the tumor. In addition, all patients had or developed symptomatic obstructive hydrocephalus requiring shunting procedures. Three of the patients are alive with a follow-up of 4 to 12 years. It is remarkable that these tumors are so rare, given that the ependymal surface area of the third ventricle is greater than that of the fourth. The management of these tumors should include aggressive surgical resection, radiation therapy, and cerebrospinal fluid diversion.

Interstitial irradiation of a large, low grade ependymoma with stereotactically implanted iodine-125 seeds. Case report

In this case report a patient with a large intraventricular benign ependymoma is presented. The tumour was treated with stereotactically implanted Iodine-125 seeds and interstitial irradiation. Extension (diameter: 6.5 cm) and volume (112.5 ml) of the lesion caused the application of an unusually low dose (tumour surface dose: 40 Gy). The tumour shrank significantly within a few weeks. Follow-up at nearly 5 years shows the patient to be tumour free.

Supratentorial ependymomas of the first two decades of life. Long-term follow-up of 20 cases (including two subependymomas)

In order to better elucidate the lesser known aspects of the biological behavior and prognosis of supratentorial ependymomas in children and young adults, we studied a series of 20 patients, ages 1 to 20 years. The tumor site was extraventricular in 14 cases and intraventricular in 6 (including one third ventricle tumor). Histologically, according to World Health Organization criteria, there were 12 ependymomas (E), 2 subependymomas (SE), and 6 malignant ependymomas (ME). Of the 18 patients surviving surgery, 12 (66.6%) are alive and disease free 63 to 252 months (mean, 146 mo) after the operation; 9 harbored an E, 2 had an SE and 1 had an ME. Four patients are now out of risk of recurrence according to Collin's law. Six of the long-term survivors (50%), four E and two SE, did not receive postoperative radiotherapy. However, two patients with E, initially treated by surgery alone, had a recurrence and one subsequently died. Two ME patients showed signs of spinal metastases after subsequent operation for recurrence and shortly before death. Considering the partially good results as well as failures after surgery alone in our and in other series and the risks of irradiating the child's brain, we tried to elucidate in what cases radiotherapy could be reasonably withheld, or alternatively, when prophylactic craniospinal irradiation should be prescribed. The main conclusions of our study are the following: 1) Radical surgery alone is a reasonable option as the initial treatment for lateral ventricle tumors and for solid extraventricular tumors located far from eloquent brain areas, provided the histology is benign, especially if of the SE type.(ABSTRACT TRUNCATED AT 250 WORDS)

An overview of principles for classifying brain tumors

The purpose of this review is to clarify for the nonneuropathologist some of the confusing issues concerning the classification of brain tumors. Following a short discussion of the commonly used methods to diagnose brain tumors clinically (frozen section, light and electron microscopy, immunohistochemistry), the general principles of classifying neural tumors are presented. Grading of tumors on the basis of histological anaplasia, and the concept that tumor cells can be related to specific cytological stages of normal cellular development (cytogenetic classification) are presented. The World Health Organization system of classifying neural tumors is an attempt to develop a standardized classification scheme with as few interpretative controversies as possible, but it has required revision as new information has been gained. The major clinical and biological features of the commonest tumor groups are then discussed. It is unlikely that improvements in the classification of brain tumors will be based solely on histological information. Definitions of tumor entities that will provide more accurate prognoses and bases for effective therapy will require considerably more information at the molecular level than is currently available.

Spontaneous intracerebral hemorrhage from an unsuspected ependymoma in early infancy

A case of spontaneous intracerebral hemorrhage from an occipital ependymoma grade 2 in a 3-month-old boy is reported. The infant died 3 days after surgery. The clinical and pathomorphological characteristics are described. Despite the usually rich vascularization of these tumors, hemorrhages from intracranial ependymomas are relatively uncommon. The different forms and probable causes of bleedings are discussed.

Spinal subarachnoid hemorrhage due to a filum terminale ependymoma

We present a case of spinal subarachnoid hemorrhage due to an ependymoma of the filum terminale in a 23-year-old male. Clinical signs indicating a spinal origin of the subarachnoid hemorrhage are discussed. Subarachnoid hemorrhages are only rarely caused by an intraspinal tumor, most of which are located in the cauda equina. Our findings in this case proved the value of MRI examination in tumors of the cauda equina.

Tumours in Iceland. 15. Ependymoma. A clinicopathological and immunohistological study

Thirteen ependymomas reported to the Icelandic Cancer Registry during a 32-year period (1955-1986) were histologically reviewed and reclassified according to the WHO Histological Typing of Tumours of the Central Nervous System. The annual incidence rate of ependymoma was 0.20/100.000. Clinical observations and data on biological behaviour and immunohistochemistry are presented. Four tumours were supratentorial, six infratentorial and three intraspinal. There were ten males and three females with a mean age of 32 years (range 2.5-68). The mean postoperative survival of nine surgically treated patients was 35.5 months. Histologically, eight tumours were classical ependymomas, three anaplastic and two myxopapillary. Of 11 tumours stained for GFAP, nine were positive. Nine of 10 tumours tested were positive for vimentin, five for NSE and four for S-100. None of the 10 tumours showed reactivity with AFP, CEA, chromogranin, desmin, factor VIII, keratin or neurofilament.

Intramedullary spinal cord ependymomas--a study of 45 cases with long-term follow-up

Of the 62 patients with intramedullary spinal cord ependymoma treated surgically at our Neurosurgery Division between January 1951 and December 1990 45 had a follow-up of at least 3 years and the longest 30 years. The 28 conus-cauda equina-filum ependymomas operated during the same period are not considered in this study. An analysis of our cases and of the larger published series shows that favourable prognostic factors, apart of course from total tumour removal, which is now usually possible, are a site below the high cervical segments and a mild pre-operative symptom pattern. Patient age at diagnosis, tumour size and "low dose" (< 40 Gy) radiotherapy seem to have no influence on the prognosis. Aggressive surgical removal is the treatment of choice and also for long-term recurrence.

Supratentorial ependymomas in childhood: clinicopathological findings and prognosis

Out of 29 supratentorial ependymomas in children under 10 years of age, operated on between 1951 and 1989, 18 were situated in the hemispheres and 11 in the midline. 15 of the 18 hemispheric tumours, but only 4 of the 11 intra- or paraventricular ependymomas allowed complete removal. The operative mortality within the observation period of nearly 40 years was 27% for tumours in the midline and 11% for those in the hemispheres. The grade of malignancy rose with increasing distance from the ventricular level. 5-year survival without recurrence was 75% in grade 2 and 31% in grade 3 ependymomas. The total rate of recurrence was 58%. New tumour growth can be delayed by postoperative irradiation, at least in grade 2 ependymomas. It can be prevented, if at all, only by total resection of the primary tumour.

Application of gadolinium-DTPA magnetic resonance imaging for detection of a filum terminale myxopapillary ependymoma allowing successful surgical resection

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