Supratentorial ependymomas and subependymomas: CT and MR appearance

Imaging of supratentorial ependymomas with radio-pathological correlation

Aim

Supratentorial ependymoma (STE) is a rare tumor with distinct genetic alterations, whose imaging features have been scarcely studied. This study aims to review the computed tomography (CT) and magnetic resonance imaging (MRI) features of a cohort of histopathologically proven STE to identify the distinguishing features of STE, and look for specific signs of zinc finger translocation associated (ZFTA) fused STEs.

Methods

Ethical clearance was obtained from the institutional ethics committee. The magnetic resonance (MR) images, CT images when available, clinical details, and pathological reports of 25 patients from a single institute with histopathologically proven STE were retrospectively reviewed. Imaging features, demographic details, pathological and molecular features, and type of surgical resection were described and tabulated. Relevant associations with imaging features were computed and tabulated.

Results

The study showed that STEs are common in the pediatric population with no sex predilection. The periventricular location was the most common. A significant association between periventricular location and the presence of a cystic component (P value = 0.023) and the presence of the periwinkle sign/stellate sign (P value = 0.045) was found. Common features of ZFTA fused STEs included periventricular or intraventricular location, cystic component, necrosis, and the periwinkle sign. A significant association was found between ZFTA fusion and cystic component (P value = 0.048).

Conclusions

This study attempts to identify the imaging features of STEs and their associations with molecular pathology and surgical outcome, and the distinguishing features of ZFTA fused STEs.

Supratentorial extra-ventricular ependymoma as a mass lesion in a child: report and literature review

Supratentorial extra-ventricular ependymoma (SEE) are extremely rare in pediatric population and have varied presentation based on size, location, epicentre and compression on neurovascular structure. The authors report a 7-year-old girl presenting with seizure, who had a lobar SEE on MRI scan, successfully treated by microsurgical resection and adjuvant therapy.

Tumors of Choroid Plexus and Other Ventricular Tumors

Tumors arising inside the ventricular system are rare but represent a difficult diagnostic and therapeutic challenge. They usually are diagnosed when reaching a big volume and tend to affect young children. There is a wide broad of differential diagnoses with significant variability in anatomical aspects and tumor type. Differential diagnosis in tumor type includes choroid plexus tumors (papillomas and carcinomas), ependymomas, subependymomas, subependymal giant cell astrocytomas (SEGAs), central neurocytomas, meningiomas, and metastases. Choroid plexus tumors, ependymomas of the posterior fossa, and SEGAs are more likely to appear in childhood, whereas subependymomas, central neurocytomas, intraventricular meningiomas, and metastases are more frequent in adults. This chapter is predominantly focused on choroid plexus tumors and radiological and histological differential diagnosis. Treatment is discussed in the light of the modern acquisition in genetics and epigenetics of brain tumors.

Ependymomas in Children and Adults

Ependymomas account for approximately 5% of all CNS tumors in adults and around 10% in the pediatric population. Contrary to traditional theories supporting that ependymomas arise from ependymal cells, recent studies propose radial glial cells as the cells of origin. In adults, half of the ependymomas arise in the spinal cord, whereas in the pediatric population, almost 90% of ependymomas are located intracranially. Most of the ependymomas are usually low-grade tumors except anaplastic variants and some cases of RELA-fusion-positive ependymomas, a molecular variant consisting the most recent addition to the 2016 World Health Organization (WHO) classification. Of note, the recently described molecular classification of ependymomas into nine distinct subgroups appears to be of greater clinical utility and prognostic value compared to the traditional histopathological classification, and parts of it are expected to be adopted by the WHO in the near future. Clinical manifestations depend on the location of the tumor with infratentorial ependymomas presenting with acute hydrocephalus. Gross total resection should be the goal of treatment. The prognostic factors of patients with ependymomas include age, grade, and location of the tumor, with children with intracranial, anaplastic ependymomas having the worst prognosis. In general, the 5-year overall survival of patients with ependymomas is around 60-70%.

A Case of Lateral Ventricular Subependymoma with Intratumoral Hemorrhage <i>via</i> Neuroendoscopic Surgery

Subependymoma (SE) is a rare, usually asymptomatic, brain tumor predominantly affecting older adults and occurring in the fourth and lateral ventricles. We report a rare case of SE with intratumoral hemorrhage that could be removed by neuroendoscopy. The 81-year-old patient had been followed as an outpatient for 10 years due to an intraventricular tumor. It did not grow over the patient's lengthy follow-up. The patient was transferred to our hospital after he fainted near his home; at the time of admission, he had mild consciousness disturbance, and his Glasgow Coma Scale score was 10 points (E3V3M4). Computed tomography showed intratumoral hemorrhage and slight ventricular enlargement. Magnetic resonance (MR) imaging showed a 4 cm-sized tumor in the anterior horn of the right lateral ventricle. The lesion appeared as a mixed-intensity solid tumor and showed irregular enhancement with gadolinium. The patient underwent neuroendoscopic tumor resection on the 30^th day of the patient's hospital stay. A histopathological examination revealed small tumor cells with round nuclei scattered in the glial fibrillary background. Immunostaining was positive for glial fibrillary acidic protein; these findings are consistent with an SE diagnosis. The patient in this study had hypertension and used anticoagulants, risk factors for intratumoral hemorrhage. For intraventricular tumors with bleeding―particularly in older or more physically frail patients―minimally invasive neuroendoscopic surgery should be considered an option for tumor resection.

Supratentorial extraventricular ependymoma presenting calvarial erosion: A report of 3 cases

Calvarial erosion is an infrequent manifestation associated with oligodendrogliomas, astrocytomas, dysembryoplastic neuroepithelial tumors, astroblastomas, glioblastomas, and meningiomas. Anaplastic ependymoma (AE), a rare malignant form of ependymoma, commonly results in poor prognosis. During the last 12 years, six patients were diagnosed with supratentorial ependymomas. All of them were AEs with extraventricular location identified in the right parietal, left parietal, and left frontal lobes, respectively. Three of them, 7-, 15, and 17-year-old male patients, presented focal calvarial erosion with smooth contour. Calvarial erosion may be a diagnostic hallmark of supratentorial AEs.

Supratentorial Extraventricular Ependymomas: Imaging Features and the Added Value of Apparent Diffusion Coefficient

OBJECTIVE

To improve the understanding and the diagnosis of intracranial ependymal tumors.

METHODS

The clinical, radiological and prognostic features of 48 supratentorial extraventricular ependymomas and 74 intraventricular ependymomas were summarized and compared.

RESULTS

Supratentorial extraventricular ependymomas, most often located in the frontal lobe (33.3%) and classified as grade III (75.0%), had relatively large eccentric cysts (3.07 ± 2.03 cm), significant enhancement (84.8%), low apparent diffusion coefficient (ADC) values, and associated with higher mortality (41.3%). The majority of intraventricular lesions occurred in the fourth ventricle (86.5%) and classified as grade II (78.4%), had relatively small and multiple cystic changes (1.04 ± 0.87 cm), slight or moderate enhancement (76.9%), high ADC values and associated with lower mortality (20.7%). There were few significant differences between grade II and grade III tumors in these 2 groups, respectively. Young age, high grade and low ADC values are worse prognostic indicators for patients with supratentorial extraventricular ependymomas, but not for those with intraventricular ependymomas.

CONCLUSIONS

Conventional radiological features, combined with clinical manifestations and quantitative information provided by diffusion-weighted imaging, may not only enhance the diagnosis and assist in determining prognosis but also provide a better pathophysiological understanding of intracranial ependymal tumors.

An Insight into Pathophysiological Features and Therapeutic Advances on Ependymoma

Simple Summary

Although biological information and the molecular classification of ependymoma have been studied, the treatment systems for ependymoma are still insufficient. In addition, because the disease occurs infrequently, it is difficult to obtain sufficient data to conduct large-scale or randomized clinical trials. Therefore, this study is intended to emphasize the importance of understanding its pathological characteristics and prognosis as well as developing treatments for ependymoma through multilateral studies.

Abstract

Glial cells comprise the non-sensory parts of the central nervous system as well as the peripheral nervous system. Glial cells, also known as neuroglia, constitute a significant portion of the mammalian nervous system and can be viewed simply as a matrix of neural cells. Despite being the “Nervenkitt” or “glue of the nerves”, they aptly serve multiple roles, including neuron repair, myelin sheath formation, and cerebrospinal fluid circulation. Ependymal cells are one of four kinds of glial cells that exert distinct functions. Tumorigenesis of a glial cell is termed a glioma, and in the case of an ependymal cell, it is called an ependymoma. Among the various gliomas, an ependymoma in children is one of the more challenging brain tumors to cure. Children are afflicted more severely by ependymal tumors than adults. It has appeared from several surveys that ependymoma comprises approximately six to ten percent of all tumors in children. Presently, the surgical removal of the tumor is considered a standard treatment for ependymomas. It has been conspicuously evident that a combination of irradiation therapy and surgery is much more efficacious in treating ependymomas. The main purpose of this review is to present the importance of both a deep understanding and ongoing research into histopathological features and prognoses of ependymomas to ensure that effective diagnostic methods and treatments can be developed.

Conventional and Advanced Magnetic Resonance Imaging Features of Supratentorial Extraventricular Ependymomas

OBJECTIVE

To describe the magnetic resonance imaging characteristics of supratentorial ependymomas.

METHODS

The magnetic resonance imaging and computed tomography imaging characteristics of 49 cases of supratentorial ependymomas were analyzed retrospectively. The location, size, degree of perilesional edema, gross appearance, computed tomography attenuation characteristics, T1 and T2 signal intensity characteristics, degree of diffusion restriction, presence of calcification, and hemorrhage were documented for each lesion. The intratumoral susceptibility scores (ITSS), apparent diffusion coefficient (ADC) values, relative cerebral blood volume, and choline/N-acetyl aspartate ratios were documented where available.

RESULTS

The frontal lobe was the most common location with a mean size of 6.37 × 4.8 cm. Severe perilesional edema was evident in 30%. Heterogenous, solid-cystic appearance was present in 96% lesions, with 95% of extraventricular lesions extending from pial surface to the ventricular margin. Calcification was seen in 55% of cases. The ITSS was 3 in 85.7% of lesions. The mean ADC value calculated was 600 × 10 mm/s. The mean relative cerebral blood volume on dynamic susceptibility contrast perfusion was 4.83. The mean choline/N-acetyl aspartate ratio was 5.87. Leptomeningeal dissemination was demonstrable in 5 lesions. Four lesions were abutting the dura with frank dural invasion in one. One patient presented with disseminated disease without evidence of a primary lesion.

CONCLUSIONS

A large lesion with relatively well-defined margins, heterogeneous solid cystic appearance, extending from the pial surface to the ventricular margin, presence of calcification, and ADC values approaching those of white matter should raise a suspicion of supratentorial ependymoma. High ITSS, MR perfusion parameters, and magnetic resonance spectroscopy characteristics are similar to those of other high-grade gliomas.

Unusual Exophytic Appearance of Spinal Cord Subependymoma

BACKGROUND

Subependymomas are rare in the spinal cord. They are typically expansile, intramedullary spinal cord masses, eccentrically located with minimal gadolinium enhancement.

CASE DESCRIPTION

We present a case of subependymoma originating from the cervical cord with an unusual exophytic appearance. Hallmarks of subependymoma and treatment are reviewed.

CONCLUSIONS

This is the first case, to our knowledge, where imaging revealed a mass appearing to be completely extramedullary with a primary exophytic component. Therefore, subependymomas should remain on the differential for masses in the spinal cord that appear extramedullary and exophytic.

Surgical outcome in cortical ependymoma: A single centre experience of 18 cases

Cortical ependymomas (CE) are rare subset of supratentorial ependymoma which are located in the peripheral cortical rim without any connection to the ventricular lining. With limited cases previously reported, current knowledge on diagnosis and management of tumors is lacking. We present the largest single center experience on CE reported so far and highlight their clinico-radiological aspects, histopathological features as well the results of their surgical excision. We studied 18 CE patients undergoing surgical excision at our center between September 2009 to November 2017. Clinical, radiological, histopathological and operative data was obtained from hospital records. Functional assessment of our patients were done using the Karnofsky's performance score (KPS). Survival analysis was done using Kaplan-Meier method and log rank test. Mean age of patients in our study group was 19 ± 11.1 years. Frontal lobe was the most frequently involved region. Features of raised intracranial pressure like holocranial headache (n = 15, 83.33%) and vomiting (n = 9, 50%) were most common presenting complaints in our study. Gross total resection of tumor was achieved in eleven patients (61.11%). Histopathology showed equal number (n = 9) of WHO grade 2 and 3 ependymoma. During 111 months follow-up, four patients (22.22%) developed recurrence and three patients (16.66%) died. Five years overall survival (OS), progression-free survival (PFS) rate were 74.3% and 70.7%. In view of higher risk of progression to higher histo-pathological grade and local recurrence years after surgical excision, a long clinical and radiological follow-up is advised.

Case-based review: ependymomas in adults

Ependymomas are rare primary central nervous system (CNS) tumors in adults. They occur most commonly in the spinal cord, and have classically been graded histologically into World Health Organization (WHO) grades I, II, or III based on the level of anaplasia. Recent data are showing that genetic heterogeneity occurs within the same histological subgroup and that ependymomas arising from different CNS locations have different molecular signatures. This has renewed interest in developing targeting therapies based on molecular profiles especially given the variable outcomes with radiation and the poor results with cytotoxic agents. In this paper, we present the case of a 46-year-old woman with a classic presentation of spinal cord ependymoma and discuss the current histopathological and molecular classification for ependymomas as well as current guidelines for patient management.

Supratentorial Extraventricular Ependymoma: Retrospective Analysis of 15 Patients at a Single Institution

BACKGROUND

Supratentorial extraventricular ependymoma (STEE) is an extremely rare central nervous system (CNS) neoplasm, the clinical characteristics and optimal treatment of which remain unclear. We retrospectively analyzed the clinical characteristics and treatment outcomes of 15 patients with STEE.

METHODS

Fifteen patients with STEE were identified, and their clinical, radiologic, and surgical records were reviewed.

RESULTS

The 15 patients included 6 males (40%) and 9 females (60%), with a median age of 15 years. Nine patients (60%) underwent gross total resection, 5 patients (33.3%) underwent subtotal resection, and 1 patient (6.7%) underwent biopsy. Eight patients received adjuvant radiotherapy, and 3 received adjuvant chemotherapy. The 5-year overall survival (OS) rates of patients with World Health Organization (WHO) grade II and grade III STEE were 100% and 30%, respectively, and the corresponding 2-year progression-free survival (PFS) rates were 77.8% and 20%. The differences in OS and PFS rates between WHO grades II and III STEE were statistically significant (P < 0.01 and 0.02, respectively). Anaplastic histology (WHO grade III) was a poor prognostic factor for PFS (P = 0.04). The recurrence pattern was local recurrence in all patients; all cases were treated primarily by redo surgery. Three patients with recurrent WHO grade II STEE were alive at more than 64, 52, and 44 months after redo surgery.

CONCLUSIONS

STEE is an extremely rare CNS neoplasm. The histological grade of STEE is an important prognostic factor. Microsurgical resection might play a major role in both initial treatment and treatment of recurrent tumors.

Adult Supratentorial Extraventricular Anaplastic Ependymoma: Therapeutic Approach and Clinical Review

We report a 69-year-old patient with left paresthesia and hemiparesis. Magnetic resonance imaging revealed a right frontoparietal cystic tumor. A subtotal surgical resection was performed, and an Ommaya reservoir was left in place. The pathological diagnosis was supratentorial extraventricular anaplastic ependymoma. Radiation therapy was administered, and Ommaya reservoir drainages were performed. Four months after, her clinical status deteriorated after a reservoir drainage and image revealed an acute hemorrhage. An additional resection was carried out, and chemotherapy was undergone. One month later the tumor relapsed and the patient died 18 months after initial diagnosis. Some poor prognostic factors have been suggested in the literature: Young age, incomplete tumor resection – eloquent area location, histological anaplasia, supratentorial, and extraventricular locations. Ommaya reservoirs may be used in cystic lesions as a temporary measure only. Surgery is the mainstay of therapy with adjuvant radiotherapy and/or chemotherapy.

Subependymomas Are Low-Grade Heterogeneous Glial Neoplasms Defined by Subventricular Zone Lineage Markers

OBJECTIVE

Subependymomas are infrequent, low-grade gliomas associated with the ventricular system and the spinal cord. Little is known about the origin and natural history of these slow-growing lesions.

METHODS

We identified all patients with pathologically proven subependymomas presenting to our institution between 1998 and 2016. We retrospectively reviewed clinical, radiographic, histologic, and surgical outcomes data in all patients who underwent surgical resection. Immunohistochemical analyses for cell lineage markers were performed.

RESULTS

A total of 31 patients with pathologically proven subependymomas were identified. Of these, 7 asymptomatic lesions were discovered at autopsy and 24 symptomatic cases were treated surgically. There were 15 (48%) lateral ventricle tumors, 11 (35%) fourth ventricular tumors, and 5 (17%) spinal tumors. Symptomatic intracranial lesions most commonly presented with headaches and balance and gait abnormalities. Subependymomas had no distinguishing radiographic features that provided definitive preoperative diagnosis. At last follow-up, no patient treated surgically experienced recurrence. Immunohistochemical analyses demonstrated a diffusely GFAP-positive glial neoplasm with mixed populations of cells that were variably positive for Olig2, NHERF1, Sox2, and CD44. The Ki67 proliferation index was generally low (<1% in many of the tumors).

CONCLUSIONS

Subependymomas demonstrate mixed populations of cells expressing glial lineage markers as well as putative stem cell markers, suggesting these tumors may arise from multipotent glial progenitors that reside in the subventricular zone. Definitive diagnosis requires surgical sampling. Although the clinical course of subependymomas appears benign, the inability to radiographically diagnose these lesions, and the possibility of an alternative malignant lesion support a low threshold for early and safe maximal resection.

Clinical, radiological, and histological features and treatment outcomes of supratentorial extraventricular ependymoma: 14 cases from a single center

OBJECTIVE Reports on supratentorial extraventricular ependymoma (STE) are relatively rare. The object of this study was to analyze the clinical, radiological, and histological features and treatment outcomes of 14 patients with STE. METHODS Overall, 227 patients with ependymoma underwent surgical treatment in the authors' department between January 2010 and June 2015; 14 of these patients had STE. Data on clinical presentation, radiological studies, histopathological findings, surgical strategies, and treatment outcomes in these 14 cases were retrospectively analyzed. RESULTS The patients consisted of 6 women and 8 men (sex ratio 0.75). Mean age at diagnosis was 24.5 ± 13.5 years (range 3-48 years). Tumors were predominantly located in the frontal and temporal lobes (5 and 4 cases, respectively). Typical radiological features were mild to moderate heterogeneous tumor enhancements on contrast-enhanced MRI. Other radiological features included well-circumscribed, "popcorn" enhancement and no distinct adjoining brain edema. Gross-total resection was achieved in 12 patients, while subtotal removal was performed in 2. Radiotherapy was administered in 7 patients after surgery. Seven tumors were classified as WHO Grade II and the other 7 were verified as WHO Grade III. The mean follow-up period was 22.6 months (range 8-39 months). There were 3 patients with recurrence, and 2 of these patients died. CONCLUSIONS Supratentorial extraventricular ependymoma has atypical clinical presentations, various radiological features, and heterogeneous histological forms; therefore, definitive diagnosis can be difficult. Anaplastic STE shows malignant biological behavior, a higher recurrence rate, and a relatively poor prognosis. Gross-total resection with or without postoperative radiotherapy is currently the optimal treatment for STE.

Pediatric Ependymoma

Over the past 150 years since Virchow's initial characterization of ependymoma, incredible efforts have been made in the classification of these tumors and in the care of pediatric patients with this disease. While the advent of modern neurosurgery and the optimization of radiation have provided significant gains, a more complex but incomplete picture of pediatric ependymomas has begun to form through a combination of international collaborations and detailed genetic and histologic characterizations. This review includes and synthesizes the clinical understanding of pediatric ependymoma and their developing molecular insight into what is truly a family of malignancies in which distinct members require different surgical approaches, radiation plans, and targeted therapies.

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.

Ependymoma: a heterogeneous tumor of uncertain origin and limited therapeutic options

Ependymomas are tumors that typically occur with an age-based site preference, with adults harboring supratentorial and spinal tumors and pediatric tumors being mainly in the posterior fossa. Despite their similar histologic appearance, the prognosis varies significantly by age and tumor location, with a better prognosis in increasing age. The mainstay of treatment remains surgical excision with or without radiation therapy as the tumor biology is poorly understood and chemotherapy is generally considered to be ineffective. More recently, molecular biology data have increased our understanding of the genetic and epigenetic changes that drive these tumors, but still it will take a lot of effort to find effective chemotherapeutic regimens. Currently, we are trying to define a subset of tumors, for which radiation therapy can be avoided.

CNS and spinal tumors

Primary CNS tumors consist of a diverse group of neoplasms originating from various cell types in the CNS. Brain tumors are the most common solid malignancy in children under the age of 15 years and the second leading cause of cancer death after leukemia. The most common brain neoplasms in children differ consistently from those in older age groups. Pediatric brain tumors demonstrate distinct patterns of occurrence and biologic behavior according to sex, age, and race. This chapter highlights the imaging features of the most common tumors that affect the child's CNS (brain and spinal cord).

Imaging characteristics of supratentorial ependymomas: Study on a large single institutional cohort with histopathological correlation

Background:

Supratentorial ependymoma (STE) is a tumor whose unique clinical and imaging characteristics have not been studied. Histopathologically, they resemble ependymoma elsewhere. We retrospectively reviewed the imaging findings with clinicopathological correlation in a large number of patients with STE to identify these characteristics.

Materials and Methods:

Computed tomography (CT) magnetic resonance images (MRI), pathology reports, and clinical information from 41 patients with pathology-confirmed STE from a single institution were retrospectively reviewed. CT and MRI findings including location, size, signal intensity, hemorrhage, and enhancement pattern were tabulated and described separately in intraventricular and intraparenchymal forms.

Results:

STE was more common in pediatric age group and intraparenchymal was more common than intraventricular form. The most common presentation was features of raised intracranial tension. There were equal numbers of Grade II and Grade III tumors. The imaging characteristics in adult and pediatric age group were similar. The tumor was large and had both solid and cystic components. Advanced imaging such as diffusion, perfusion, and spectroscopy were suggestive of high-grade tumor. Only differentiating factor between Grade II and Grade III was the presence of calcification. 1234 rule and periwinkle sign which we have described in this article may help characterize this tumor on imaging.

Conclusion:

This series expands the clinical and imaging spectrum of STE and identifies characteristics that should suggest consideration of this uncommon diagnosis.

Systematic comparison of MRI findings in pediatric ependymoblastoma with ependymoma and CNS primitive neuroectodermal tumor not otherwise specified

BACKGROUND

Ependymoblastoma (EBL), ependymoma (EP), and primitive neuroectodermal tumors of the central nervous system not otherwise specified (CNS-PNET NOS) are pediatric brain tumors that can be differentiated by histopathology in the clinical setting. Recently, we described specific MRI features of EBL. In this study, we compare standardized MRI characteristics of EBL with EP and CNS-PNET NOS in a series comprising 22 patients in each group.

METHODS

All 66 centrally reviewed cases were obtained from the database of the German multicenter HIT trials. We systematically analyzed the initial MRI scans at diagnosis according to standardized criteria, and paired comparison was performed for EBL and EP, as well as for EBL and CNS-PNET NOS.

RESULTS

We found differences between EBL and EP regarding age at diagnosis, MR signal intensity, tumor margin and surrounding edema, presence and size of cysts, and contrast enhancement pattern. Although MRI appearance of EBL shares many features with CNS-PNET NOS, we revealed significant differences in terms of age at diagnosis, tumor volume and localization, tumor margins, edema, and contrast enhancement.

CONCLUSION

This is the first study that systematically compares multiple parameters of MRI in pediatric EBL with findings in EP and CNS-PNET NOS. Although a definite differentiation by means of MRI alone might not be feasible in the individual case, we identify significant differences between these tumor entities.

Clinical, radiological, and pathological features in 43 cases of intracranial subependymoma

OBJECT

Intracranial subependymomas are rarely reported due to their extremely low incidence. Knowledge about subependymomas is therefore poor. This study aimed to analyze the incidence and clinical, radiological, and pathological features of intracranial subependymomas.

METHODS

Approximately 60,000 intracranial tumors were surgically treated at Beijing Tiantan Hospital between 2003 and 2013. The authors identified all cases in which patients underwent resection of an intracranial tumor that was found to be pathological examination demonstrated to be subependymoma and analyzed the data from these cases.

RESULTS

Forty-three cases of pathologically confirmed, surgically treated intracranial subependymoma were identified. Thus in this patient population, subependymomas accounted for approximately 0.07% of intracranial tumors (43 of an estimated 60,000). Radiologically, 79.1% (34/43) of intracranial subependymomas were misdiagnosed as other diseases. Pathologically, 34 were confirmed as pure subependymomas, 8 were mixed with ependymoma, and 1 was mixed with astrocytoma. Thirty-five patients were followed up for 3.0 to 120 months after surgery. Three of these patients experienced tumor recurrence, and one died of tumor recurrence. Univariate analysis revealed that shorter progression-free survival (PFS) was significantly associated with poorly defined borders. The association between shorter PFS and age < 14 years was almost significant (p = 0.51), and this variable was also included in the multivariate analysis. However, multivariate analysis showed showed only poorly defined borders to be an independent prognostic factor for shorter PFS (RR 18.655, 95% CI 1.141–304.884, p = 0.040). In patients 14 years of age or older, the lesions tended to be pure subependymomas located in the unilateral supratentorial area, total removal tended to be easier, and PFS tended to be longer. In comparison, in younger patients subependymomas tended to be mixed tumors involving the bilateral infratentorial area, with a lower total removal rate and shorter PFS.

CONCLUSIONS

Intracranial subependymoma is a rare benign intracranial tumor with definite radiological features. Long-term survival can be expected, although poorly defined borders are an independent predictor of shorter PFS. All the features that differ between tumors in younger and older patients suggest that they might have different origins, biological behaviors, and prognoses.

The fine structure of ependymomas

Electron microscopy is a useful diagnostic technique in order to confirm or establish a definitive diagnosis in brain tumors that may have an atypical histological pattern, which requires a concrete diagnosis. In ependymomas, electron microscopy reveals morphological characters that have a pathognomonic diagnostic value, therefore allowing a definitive diagnosis. The main fine structural criteria of ependymomas consist of the numerous microvilli and cilia, which are incorporated in the cell body or extended freely in the intracellular space; the centriole or blepharoplast, which is located in the basis of the cilia; the large number of the fragmented microtubules in the perikaryon and the cellular processes (any small cellular projection into the neutrophil or intracellular space); the junctional apparatus between the cells, such as zonula adherens, zonula occludens and puncta adherentia; the basement membrane-like structure, seen in papillary ependymomas and ependymomas of the filum terminale; and the elongated cells in the loose intracellular space, commonly seen in myxopapillary ependymomas.

Cerebral astroblastoma: A radiopathological diagnosis

Astroblastoma is a rare glial neoplasm whose histogenesis has been clarified recently. It primarily occurs in children and young adults. We are reporting a case of 12-year-old girl child who presented with features of raised intracranial tension and generalized tonic-clonic seizures. Brain magnetic resonance imaging revealed a large well-circumscribed, cystic lesion without perifocal edema, and enhancing mural nodule in right parietal region. A radiological differential diagnosis of pilocytic astrocytoma and cerebral astroblastoma was made. A complete excision was done and histologically the lesion turned out to be an astroblastoma. We review the histology, immunohistochemistry, and imaging features of astroblastoma and survey the current literature, treatment strategies, and prognostic aspects for the management of this rare neoplasm.

Infratentorial and intraparenchymal subependymoma in the cerebellum: case report

Subependymomas are rare benign tumors located in the ventricular system. Intraparenchymal subependymoma is extremely rare; only 6 cases have been reported, and all were located in the supratentorial region. We describe a case of infratentorial, intraparenchymal subependymoma in a 28-year-old man with intermittent headache. Imaging revealed a well-demarcated cystic and solid cerebellar mass near the fourth ventricle. The mass had a microcystic component and calcification without contrast enhancement. Complete surgical excision was performed, and histopathology confirmed a subependymoma.

Atypical hemorrhagic presentation of a fourth ventricle subependymoma: case report

To present a case of a fourth ventricle subependymoma (SE) with a spontaneous acute subarachnoid intra-cisternal bleeding. A 33-year-old man was admitted with 5 days history of oppressive occipital headache and neck pain without additional neurological focus. Unenhanced computed tomography (CT) scan demonstrated an isointense mass located in the fourth ventricle with a spontaneously hyperdense acute extratumoral hemorrhage in the cisterna magna. Contrast-enhanced magnetic resonance imaging (MRI) revealed a well-delimitated non-enhanced tumor, hypointense on T₁-weighted and hyperintense on T_2-weighted images, involving the floor of the fourth ventricle and extending caudally into the cervical spinal canal via foramen magnum. Intraoperative, a large blood clot was removed and a macroscopically hypovascularlesion was completely excised from the right lateral recess and the floor of the fourth ventricle. Intra and postoperative immuno-histopathological examination revealed a SE. The patient has a normal postoperative course and was discharged in the fifth postoperative day. A 10-month postoperative MRI study confirmed a complete tumor resection. Symptomatic SEs should be surgically treated emphasizing the urgency in the presence of hemorrhage. The interest of this case is to demonstrate that infratentorial SEs although extremely rare, might present with acute subarachnoid bleeding.

How specific is the MRI appearance of supratentorial atypical teratoid rhabdoid tumors?

BACKGROUND

Supratentorial atypical teratoid rhabdoid tumor (ATRT) in many cases has a distinctive appearance on post-gadolinium MRI.

OBJECTIVE

We sought to determine whether this is a unique appearance allowing ATRT to be distinguished accurately from other types of pediatric supratentorial tumors.

MATERIALS AND METHODS

Retrospective review of all available preoperative MRI of pediatric supratentorial tumors at two tertiary children's hospitals, and systematic literature review of case series and reports describing the MRI imaging appearances of supratentorial ATRT.

RESULTS

We had 61 supratentorial tumors, including 32 gliomas, 6 ATRT, 8 ependymomas, 6 gangliogliomas, 2 pilomyxoid astrocytomas, 3 primitive neuro-ectodermal tumors, 2 choroid plexus papillomas, and 2 meningiomas. ATRT presented in significantly younger patients than astrocytomas (mean age 2.6 years vs. 9.9 years, P < 0.05). The visual pattern of a thick, wavy (irregular) heterogeneously enhancing wall around a cystic center was seen in 5/6 (83%) ATRTs and only 3/55 (5.4%) other tumors (P < 0.0001), for specificity of 95%, sensitivity of 83%, positive predictive value of 63% and a negative predictive value of 95%.

CONCLUSION

A supratentorial tumor with a thick, wavy (irregular) heterogeneously enhancing wall surrounding a central cystic region is suggestive of ATRT in the appropriate clinical setting, especially in a child of preschool age.

Cystic with mural nodule: Unusual radiological presentation of supratentorial anaplastic ependymoma

Supratentorial anaplastic ependymoma is an uncommon tumor which can rarely present as a cyst with mural nodule on imaging. Authors present this unusual radiological appearance of supratentorial extraventricular anaplastic ependymoma in a 9-year-old boy.

Contrast-enhanced MR imaging in neuroimaging

MR imaging without and with gadolinium-based contrast agents (GBCAs) is an important imaging tool for defining normal anatomy and characteristics of lesions. GBCAs have been used in contrast-enhanced MR imaging in defining and characterizing lesions of the central nervous system for more than 20 years. The combination of unenhanced and GBCA-enhanced MR imaging is the clinical gold standard for the noninvasive detection and delineation of most intracranial and spinal lesions. MR imaging has a high predictive value that rules out neoplasm and most inflammatory and demyelinating processes of the central nervous system.

Supratentorial neurenteric cyst associated with a intraparenchymal subependymoma

Neurenteric cyst is a rare developmental lesion that very infrequently is localised supratentorially. Intraparenchymal subependymoma is an even more rare benign tumour. The authors report the case of a 45-year-old gentleman with a background of drug resistant epilepsy. An MRI was performed which showed a left frontal cystic lesion with a solid component. Histopathology confirmed a type C neurenteric cyst associated with an intraparenchymal subependymoma. Following enlargement of the lesion and worsening of symptoms he was referred to our institution for further management. A frontotemporal craniotomy was performed for excision of the lesion but recurrence occurred within 1 year. The lesion was further excised and 19 months post re-excision the patient is seizure free with no evidence of recurrence on MRI.

Ventricular and Extraventricular Ependymal Tumors in 18 Cats

Ependymal tumors are reported rarely in domestic animals. The aims of this study were to examine the clinical and pathologic features of ventricular and extraventricular ependymomas and subependymomas in 18 domestic cats examined between 1978 and 2011. Parameters examined included age, sex, breed, clinical signs, and macroscopic and histopathologic features. The mean age of affected cats was 9 years, 4 months; median age, 8.5 years. There were 8 female and 4 male cats, and 6 cats for which sex was not recorded. Breeds included 10 domestic shorthaired, 2 domestic longhaired, 1 Persian, and 1 Siamese. Clinical signs included altered mentation or behavior, seizures, circling, propulsive gait, generalized discomfort, and loss of condition. The tumors often formed intraventricular masses and usually arose from the lining of the lateral or third ventricles, followed by the fourth ventricle, mesencephalic aqueduct, and spinal cord central canal. Three tumors were extraventricular, forming masses within the cerebrum and adjacent subarachnoid space. Histologically, 15 tumors were classified as variants of ependymomas (classic, papillary, tanycytic, or clear cell) and 3 as subependymomas. Tumors were generally well demarcated; however, 6 ependymomas focally or extensively infiltrated the adjacent neural parenchyma. Characteristic perivascular pseudorosettes were observed in all ependymomas; true rosettes were less common. Some tumors had areas of necrosis, mineralization, cholesterol clefts, and/or hemorrhage. This cohort study of feline ependymal tumors includes subependymoma and primary extraventricular ependymoma, variants not previously described in the veterinary literature but well recognized in humans.

[Imaging of lateral ventricle tumors]

Lateral ventricular neoplasms are rare, and account for 50% of all intraventricular tumors in adults and 25% in children. Although these neoplasms are easily detected with computed tomography (CT) and magnetic resonance imaging (MRI), both techniques are relatively unspecific in identifying the type of tumor. However, few imaging patterns are specific for a particular pathological process and useful conclusions can be made from the morphological appearance of the lesion, its location and enhancement pattern. The aim of this article was to review and illustrate the CT and MRI findings of a wide spectrum of tumors of the lateral ventricle. We reviewed choroid plexus tumors, meningioma, subependymal giant cell astrocytoma, central neurocytoma, and less frequent lesion such as lymphoma and metastases.

Spontaneous acute hemorrhage within a subependymoma of the lateral ventricle: successful emergent surgical removal through a frontal transcortical approach

INTRODUCTION. Subependymomas are benign neoplasms intimately related to the ventricular system which only exceptionally associate hemorrhagic events. We present neuroradiological and pathological evidences of intratumoral hemorrhage within a single case of subependymoma operated on at our institution. Additionally we analyze retrospectively the well-defined reports of similar cases published in the scientific literature. CASE REPORT. A 71-year-old man on anticoagulant therapy presented with abrupt and progressive deterioration of his level of consciousness. Emergent computed tomography and magnetic resonance imaging evidenced signs of acute bleeding within a mass located at the frontal horn of the left lateral ventricle, producing obstructive biventricular hydrocephalus. The lesion was immediately and completely removed through a left frontal transcortical approach. Pathological diagnosis was consistent with subependymoma displaying areas of microhemorrhage. After surgery the patient developed global anterograde and retrograde amnesia. CONCLUSIONS. A spontaneous hemorrhagic event within an asymptomatic lateral ventricle subependymoma can result in a surgical emergence as a consequence of sudden obstruction of cerebrospinal fluid pathways. Prompt and radical surgical removal of the mass, which allows a rapid resolution of hydrocephalus and prevents the risk of rebleeding, may constitute the safest management strategy.

Recurrent pituitary ependymoma: a complex clinical problem

Ependymomas rarely arise from the region of the pituitary fossa, with only four cases previously reported in the literature. We present a complex case of a recurrent ependymoma of the parasellar region which has been difficult to clinically manage due to its tendency to recurrence. Our patient has had four operations over the last 28 years, with external beam radiotherapy, but still has residual tumor and is currently panhypopituitary and with significant visual loss. We believe there is considerable uncertainty as to the optimal management of any future progression, which seems likely, and are currently considering the use of radiosurgery with careful sparing of the optic chiasm, or possibly the chemotherapeutic agent temozolomide. Our case emphasises the recurrent nature of this rare but difficult tumor.

Huge supratentorial extraventricular anaplastic ependymoma presenting with massive calcification--case report

A 15-year-old boy presented with an anaplastic supratentorial ependymoma causing massive intratumoral calcification, without contributory medical and family history, and manifesting as persistent headache for 2 months. Physical examination found no neurological deficit except for visual defect in the right lower quadrant, with intact visual acuity. Blood examination showed no abnormalities. Cranial computed tomography revealed a huge calcified mass in the left parietooccipital lobe, with extensive perilesional brain edema. Cranial radiography showed diffuse and symmetrical thinning of the calvarial bone. Magnetic resonance imaging confirmed the tumor as an assembly of medullated masses with extraventricular location, 7 x 6.5 x 6.5 cm in diameter, and appearing as heterogeneous intensity on both T(1)- and T(2)-weighted images with inhomogeneous enhancement except for the central cores. The patient underwent tumor resection. Intraoperative findings revealed that the cortical veins overlying the tumor were reddish and moderately engorged. The hypervascular tumor, entirely extraventricular in location, was totally resected without neurological deterioration. Histological examination revealed that the tumor was highly cellular with hyperchromatic nuclei and cell atypia. Necrosis, mitotic figures, and perivascular pseudorosette formations were frequently seen. Immunohistochemical study showed positive staining for glial fibrillary acidic protein, S-100 protein, vimentin, and epithelial membrane antigen, but negative for synaptophysin. The MIB-1 labeling index was 26.5%. The findings were compatible with anaplastic ependymoma (World Health Organization classification grade 3). Ependymoma should be included in the differential diagnosis of a supratentorially located, extraventricular mass with massive intratumoral calcification.

Subependymoma revisited: clinicopathological evaluation of 83 cases

OBJECT

Subependymomas are rare ependymal neoplasms. To date, a large clinicopathologic study of these benign neoplasms treated with modern neurosurgical techniques has not been reported.

METHODS

Eighty-three cases of subependymoma were retrieved from the files of the Armed Forces Institute of Pathology. Clinicopathological features were reviewed; chromogenic in situ hybridization analysis for chromosome 22 was performed (n = 8), and patient follow-up was obtained (n = 34). Overall, the patients included 68 males and 15 females, 1.5 to 85 years of age (mean, 51.0 years). Twenty-seven cases were discovered at autopsy and the remaining were surgical specimens (n = 56). Tumors arose in the posterior fossa (n = 43), lateral ventricles (n = 37), spinal cord (2) and only one arose in the temporal horn. Tumors ranged in size from 2.0 mm to 60 mm in greatest dimension (mean, 23.0 mm). Eighteen-percent (15/83) of subependymomas exhibited a mixed histologic pattern; that is, subependymoma together with another glial tumor. The most common mixture (13/15) was subependymoma and ependymoma. Surgical excision was used in all symptomatic patients; 10 patients received radiation. Four patients developed a recurrence due to incomplete excision. All patients were without evidence of disease at the last follow-up: alive (n = 28) or dead (n = 8).

CONCLUSIONS

Age is the only variable found to be significantly associated with survival. Currently, surgical methods result in an excellent long-term clinical outcome. Subependymomas do not appear to be associated with NF2 mutations.

Astroblastoma presenting with intracerebral hemorrhage misdiagnosed as dural arteriovenous fistula: review of a rare entity

BACKGROUND

Astroblastoma is one of the most unusual types of tumors whose histogenesis has been recently clarified. It occurs mainly among children and young adults. It is grossly well demarcated and shows histologically characteristic perivascular pseudorosettes with frequent vascular hyalinization. Immunohistochemically, the tumor cells show diffuse strong positivity for GFAP, S-100 protein, vimentin, as well as neuron-specific enolase and focal positivity for EMA.

CASE DESCRIPTION

Our patient is a 33-year-old gentleman who presented with intraparenchymal hemorrhage in the left temporal lobe. A 4-vessel cerebral angiogram revealed a dural AVF in the left posterior temporal area. The lesion was resected, and pathology showed a GFAP-positive lesion with prominent astroblastoma rosettes. There was abundant hemosiderin consistent with a prior hemorrhage. Because of its high degree of proliferation, the presence of astroblastic pseudorosettes, prominent perivascular hyalinization, regional hyaline changes, and pushing borders with regard to the adjacent brain, the tumor was considered anaplastic.

CONCLUSIONS

Astroblastoma is a rare pure pathologic entity--a distinct form of astrocytic gliomas. The diagnosis of astroblastoma is often difficult because of the astroblastic aspects that can be found in astrocytic tumors, in ependymomas, and in nonneuroepithelial tumors. The natural history seems to be between astrocytomas and glioblastomas. Total resection and radiation therapy seem to be the advisable treatments.

Subependymomas: An analysis of Clinical and Imaging Features

OBJECTIVE:

Subependymomas are slow-growing, benign tumors usually found incidentally in the fourth ventricle at autopsy. They are typically associated with the ventricular system and become apparent clinically only when symptoms of hydrocephalus or mass effect develop. We review clinical, histological, and contemporary radiographic presentations of 16 subependymomas, including 2 intraparenchymal tumors.

METHODS:

We retrospectively evaluated eight patients with pathologically proven subependymomas. Initial magnetic resonance imaging and magnetic resonance spectroscopy were reviewed when available. Imaging was also available on eight outside subependymoma cases reviewed by our radiology department.

RESULTS:

Twelve of these subependymomas were intraventricular, one was in the posterior fossa, two were intraparenchymal, and one was an intramedullary spinal cord tumor. These lesions were hypo- to hyperintense on T1- and T2-weighted magnetic resonance imaging, with minimal to moderate enhancement. Initial complaints included headache, seizures, tingling sensations, and weakness. Among our eight patients who underwent gross total resection with no adjuvant therapy, no recurrences have been noted on follow-up magnetic resonance imaging.

CONCLUSION:

Subependymomas are rare, representing only 0.51% of all central nervous system tumors operated on during an 8-year period at the University of Utah. Clinical symptoms were associated with tumor location: intracranial masses caused headaches, seizures, and neurological complaints, and spinal cord locations resulted in neurological deficit. The authors review the clinical presentation, management, and contemporary radiographic appearance of this rare tumor.

Supratentorial Cortical Ependymoma: Report of Three Cases

OBJECTIVE AND IMPORTANCE:

Extraventricular ependymomas account for 50% of supratentorial ependymomas. Some tumors may extend to the gray matter reaching the pial surface, but pure cortical ependymomas are uncommon. Here, we report three patients with supratentorial intracortical ependymoma.

CLINICAL PRESENTATION:

We reviewed the clinicopathological findings of all patients operated on for ependymomas at the Bellaria Hospital during an 11-year period and found three lesions described as cortical ependymomas. The three lesions represented 2.5% of all ependymal tumors and 21.4% of supratentorial tumors operated on during the study period. The patient were aged 52, 24, and 11 years (mean, 32.3 yr). One was female. All presented with seizures. On imaging, the lesions were confined to the gray matter, were solid, and demonstrated diffuse enhancement.

INTERVENTION:

Gross total resection was achieved in all instances. Two patients were treated with surgery, and one was treated with surgery and postoperative radiotherapy. All tumors were low grade. After a mean follow-up of 92.6 months, no patient had recurrence or leptomeningeal dissemination. Review of preoperative magnetic resonance imaging scans confirmed an intracortical location. Routine sections were reviewed, and additional immunoreactions for epithelial membrane antigen, glial fibrillary acidic protein, synaptophysin, neurofilament proteins, S-100 protein, and Ki-67 and electron microscopy were performed.

CONCLUSION:

Cortical ependymomas seem to behave as benign tumors amenable to surgical removal. Local recurrence and leptomeningeal dissemination seem to be unlikely. Postoperative radiotherapy is unnecessary.

Supratentorial malignant ependymoma in childhood: 16 years without relapse after hemispherectomy

INTRODUCTION

Malignant intracranial ependymomas in childhood have a poor prognosis, supratentorial ependymomas have the poorest clinical course with a survival rate after 5 years of 45%. The most important prognostic factor in these cases is a radical operation, which cannot usually, however, prevent relapse.

CASE REPORT

We demonstrate the case of a large malignant ependymoma of the left cerebral hemisphere in a child who has so far lived for 16 years without relapse after an extensive but uncomplicated left-sided hemispherectomy. The patient has also shown an improvement in her preoperative neurologic deficits. Her epilepsy, which was difficult to manage preoperatively, has been completely eliminated. She went to a special school for handicapped children and now works there. She does not need any help in handling everyday activities.

CONCLUSION

This case shows the significance of complete tumor resection in malignant ependymomas, which may, under certain circumstances, lead to lasting tumor control.

Supratentorial extraventricular ependymal neoplasms

BACKGROUND

Published research on the clinicopathologic features of extraventricular ependymal neoplasms of the cerebral hemispheres has been scant.

METHODS

Thirty-two archival cases were studied to investigate the prognostic impact of clinicopathologic parameters including flow cytometry, the proliferation (Ki-67) labeling index, and p53 expression.

RESULTS

Among these 32 cases were 2 subependymomas, 19 ependymomas, and 11 anaplastic ependymomas. No significant gender predilection was observed, and 45% of patients were in their second or third decade of life. The left cerebral hemisphere was 1.5 times more commonly involved. On available imaging studies, lesions were often cystic, with or without a mural nodule. Tumors expressed glial fibrillary acidic protein (87%), S-100 protein (77%), cytokeratin (43%), and epithelial membrane antigen (17%). Ki-67 proliferation index paralleled tumor grade. Immunoreactivity for p53 protein was observed in the 2 cases of subependymoma, in 10 of 11 anaplastic ependymomas, and in 6 of 17 ependymomas. Flow cytometry performed in 27 tumors revealed diploidy in 20 cases and aneuploidy in 4 cases (3 anaplastic and 1 classic ependymomas), with S-phase fraction ranging from 0.2-9.7. Eleven subjects were additionally treated with radiotherapy, and 3 with chemotherapy. Follow up was available in 25 (78%) patients.

CONCLUSIONS

The results of the current study suggest that there is no significant relation between histopathology, Ki-67 proliferation index, p53 immunolabeling, tumor ploidy, and biologic behavior.

Imaging Predictors of Intracranial Ependymomas

OBJECTIVE

To identify significant imaging prognostic factors for intracranial ependymomas.

METHODS

This series includes 32 patients (18 male and 14 female), with an age at surgery ranging from 1 to 69 years (median, 20.5 years). The preoperative images and medical records were reviewed. The following imaging predictors, including tumor size, consistency, signal character, enhanced pattern, calcification, hemorrhage, perifocal edema, and tumor spread, were analyzed by 2 radiologists independently. Overall survival and progression-free survival were calculated by the Kaplan and Meier method. The difference in these imaging predictors in terms of overall survival and progression-free survival was tested for statistical significance by the log-rank test. Multivariate analysis was also performed using the Cox proportional hazard model.

RESULTS

The results revealed that the presence of tumor spread on preoperative images was the only significant imaging predictor in overall and progression-free survivals (P < 0.0001). The hazard ratio of progression-free survival in the presence of tumor spread on preoperative images was 18.59 (95% confidence interval: 1.57-220.13; P = 0.020).

CONCLUSION

The presence of tumor spread on preoperative images is the only significant imaging predictor for patients with intracranial ependymomas.