Supratentorial ependymoma: CT appearance

A rare presentation of extra-axial supratentorial ependymoma with subdural hematoma mimicking a parasagittal meningioma

Introduction

Primary extra-axial ependymomas, though rare, the majority of such lesions are identified as WHO grade III ependymomas. These ependymomas may mimick a meningioma on radiological investigations which can be confirmed by histopathology.

Research Question

We show in this case report a rare presentation of extra-axial supratentorial ependymoma with concomitant subdural hematoma mimicking a parasagittal meningioma.

Material and Methods

A 59 years lady with no known comorbidities presented with weakness of right half of body and decreased speech for 2 days. She was aphasic. Contrast MRI brain revealed an extra-axial dural-based homogenously enhancing lesion in the left anterior 1/3^rd parasagittal area with left frontotemporoparietal chronic subdural hematoma. With a provisional diagnosis of meningioma, the patient was subjected to bifrontal open-book craniotomy with gross total excision of lesion with periosteal graft duraplasty and acrylic cranioplasty. Left sided frontotemporal subacute SDH with thin greenish yellow membrane was present. In post operative period, patient quickly became E4V5M6 with power of 4/5 in the right half of body which was same as compared to the preoperative period.

Results

The biopsy of the mass, however, revealed features suggestive of extra-axial supratentorial ependymoma (WHO Grade III). Immunohistochemistry supported the diagnosis of supratentorial ependymoma, NOS. The patient was then referred for further chemoradiation.

Discussion and Conclusion

We report the first case of extra-axial supratentorial ependymoma mimicking a parasagittal meningioma occurring with adjacent subdural hematoma. Clinical and imaging background along with a complete pathological examination with immunohistochemical study is essential to confirm the diagnosis of rare brain tumours.

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.

Cortically based cystic supratentorial RELA fusion-positive ependymoma: a case report with unusual presentation and appearance and review of literature

Ependymomas are rare central nervous system tumors that can arise anywhere in the neuroaxis. Supratentorial and posterior fossa ependymomas were identified as distinct diseases after extensive molecular analysis. The 2016 World Health Organization update further introduced RELA fusion-positive ependymoma as a novel entity as a subset of supratentorial ependymomas indicating the presence of C11orf95-RELA fusion genes. RELA fusion-positive ependymomas are commonly intraventricular, though they may rarely manifest as extraventricular, cortically-based tumors. They are commonly large solid, mixed solid/cystic tumors or rarely cystic. In this paper, we report a case of RELA fusion positive cortically based-cystic ependymoma and review the existing literature. Our patient is a 9-year-old boy who presented with an unusual presentation of right facial droop. He underwent gross total resection of the ependymoma, following resection, his facial droop resolved and there was no neurologic deficit.

MRI Features of Intracranial Anaplastic Ependymomas: A Comparison of Supratentorial and Infratentorial Lesions

Background: Several previous reports of anaplastic ependymomas have described their imaging features, and most of these studies were case reports. However, no studies have compared the magnetic resonance imaging (MRI) features between the infratentorial and supratentorial anaplastic ependymomas.

Objective: The goal of this study was to explore MRI characteristics for intracranial anaplastic ependymomas.

Material and Methods: We retrospectively reviewed the demographics of 165 patients and MRI findings of 60 patients with supratentorial (SAEs) and infratentorial anaplastic ependymomas (IAEs) before surgery. The demographics and MRI features for SAEs and IAEs were compared and evaluated.

Results: Among the 60 patients, most SAEs (91.7%) were extraventricular, whereas most IAEs (91.7%) were intraventricular. Of sixty intracranial anaplastic ependymomas, most lesions were well-defined (n = 45) and round-like (n = 36). On T1-weighted imaging, compared with the gray matter, the SAEs exhibited heterogeneous signal intensity, whereas IAEs exhibited iso-hypointense signals. T2 signals exhibited greater associations with hyperintense signals in IAEs; however, SAEs showed hyperintense or hypointense–hyperintense. On diffusion-weighted imaging (DWI), almost all solid tissues of SAEs appeared as hyperintense, whereas IAEs exhibited iso-hypointense signals. Peritumoral edema and intratumoral hemorrhage occurred more frequently in SAEs. Almost all anaplastic ependymomas exhibited heterogeneous enhancement. Cysts or necrosis was associated with 56 anaplastic ependymomas; however, large cysts were more prevalent in SAEs. On magnetic resonance spectroscopy (MRS), the mean choline/creatine (Cho/Cr) and choline/N-acetyl-aspartate (Cho/NAA) ratio of anaplastic ependymomas were (6.58 ± 4.26) and (8.84 ± 6.34), respectively, representing typical high-grade tumors.

Conclusion: We demonstrate the conventional and functional MRI features of intracranial anaplastic ependymomas, including DWI and MRS. MRI characteristics, such as location, cyst, diffusion restriction, and peritumoral edema, differed between supratentorial and infratentorial locations. Cho/Cr and Cho/ NAA ratios of anaplastic ependymomas are increased.

Magnetic resonance spectroscopy in posterior fossa tumours: the tumour spectroscopic signature may improve discrimination in adults among haemangioblastoma, ependymal tumours, medulloblastoma, and metastasis

OBJECTIVES

Assessing a posterior fossa tumour in an adult can be challenging. Metastasis, haemangioblastoma, ependymal tumours, and medulloblastoma are the most common diagnostic possibilities. Our aim was to evaluate the contribution of magnetic resonance spectroscopy (MRS) in the diagnosis of these entities.

METHODS

We retrospectively evaluated 56 consecutive patients with a posterior fossa tumour and histological diagnosis of ependymal tumour, medulloblastoma, haemangioblastoma, and metastasis in which good-quality spectra at short (TE 30 ms) or/and intermediate (TE, 136 ms) TE were available. Spectra were compared using the Mann-Whitney U non-parametric test in order to select the spectral datapoints and the intensity ratios that showed significant differences between groups of lesions. Performance of these datapoints and their ratios were assessed with ROC curves.

RESULTS

The most characteristic signatures on spectroscopy were high choline (Cho) in medulloblastoma (p < 0.001), high myoinositol (mIns) in ependymal tumours (p < 0.05), and high lipids (LIP) in haemangioblastoma (p < 0.01) and metastasis (p < 0.01). Selected ratios between normalised intensity signals of resonances provided accuracy values between 79 and 95% for pairwise comparisons. Intensity ratio NI_{3.21ppm/3.55ppm} provided satisfactory discrimination between medulloblastoma and ependymal tumours (accuracy, 92%), ratio NI_{2.11ppm/1.10ppm} discriminated ependymal tumours from haemangioblastoma (accuracy, 94%), ratio NI_{3.21ppm/1.13ppm} discriminated haemangioblastoma from medulloblastoma (accuracy, 95%), and ratio NI_{1.28ppm/2.02pmm} discriminated haemangioblastoma from metastasis (accuracy, 83%).

CONCLUSIONS

MRS may improve the non-invasive diagnosis of posterior fossa tumours in adults.

KEY POINTS

• High choline suggests a medulloblastoma in a posterior fossa tumour. • High myoinositol suggests an ependymal lesion in a posterior fossa tumour. • High lipids suggest a metastasis or a haemangioblastoma in a posterior fossa tumour.

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.

Extra-axial ependymoma of the cerebral convexity: A very rare intracranial adult tumor

Background Ependymomas are rare adult tumors that originate from the ventricular system or the ependymal surface of the central canal. Extra-axial supratentorial ependymomas are extremely rare, and only five cases have been reported to date in the English literature. Case presentation A 46-year-old previously healthy male presented with a gradual painless loss of vision in the right eye. Cerebral MRI showed a right parietal-occipital lesion resembling an atypical meningioma. Surgical resection was performed, and immunohistochemical staining results concluded that it was a very uncommon location of a grade 3 ependymoma. Favorable outcome was observed one year after completion of postoperative radiotherapy. Conclusion Clinical and imaging aspects are misleading in rare brain tumors, and immunohistochemistry is essential to re-address diagnosis.

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.

Intraparenchymal infratentorial ependymoma

Ependymomas are glial series tumours that can occur throughout the neural axis, usually in close proximity to the ventricles or central canal. While the fourth ventricle is a common location for ependymoma, we present a rare case of an entirely intraparenchymal infratentorial tumour, remote from the ventricular surface, and discuss the imaging characteristics that may suggest the diagnosis. The histological features, which remain identical despite the varied morphology of intraventricular versus intraparenchymal tumours, are also considered.

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.

From the radiologic pathology archives: intraventricular neoplasms: radiologic-pathologic correlation

A variety of neoplasms may arise in the ventricular system. Intraventricular neoplasms may be discovered as an incidental finding at cross-sectional imaging or may manifest with varied symptoms depending on their location, including symptoms of increased intracranial pressure. These lesions may arise from various ventricular structures, including the ependymal lining (eg, ependymoma), subependymal layer (eg, subependymoma), or choroid plexus (eg, choroid plexus neoplasms), or they may have a cell of origin that has yet to be determined (eg, chordoid glioma). Other neoplasms involving the ventricular system include central neurocytoma, subependymal giant cell tumor, meningioma, rosette-forming glioneuronal tumor, and metastases. The differential diagnosis for intraventricular neoplasms can be broad, and many of them have similar patterns of signal intensity and contrast enhancement at imaging. However, the location of the lesion in the ventricular system-along with knowledge of the patient's age, gender, and underlying conditions-will help narrow the differential diagnosis.

Supratentorial extraventricular anaplastic ependymoma in an adult with repeated intratumoral hemorrhage

We report the case of a 61-year-old man with supratentorial extraventricular anaplastic ependymoma who presented with repeated intratumoral hemorrhage. The patient was admitted with headache. Computed tomography and magnetic resonance imaging showed an enhancing mass with intratumoral hemorrhage in the right temporal lobe. Gross total resection was performed. The tumor was well demarcated from the brain tissue, and showed no continuity with the ventricular system. Histopathological examination revealed the features of anaplastic ependymoma. Therefore, additional radiation therapy and adjuvant chemotherapy were administered. Ten months later, the tumor recurred with hemorrhage in the spinal canal. This case showed rapid malignant progression and repeated intratumoral hemorrhage within a short period of time, both of which are characteristics of anaplastic ependymomas. Close observation of the central nervous system and adjuvant radiotherapy are mandatory, even if the ependymoma presents with repeated intratumoral hemorrhage.

Unusual appearance and presentation of supratentorial subependymoma in an adult patient

We report a case of a large, heterogeneously enhancing, pathologically proven, supratentorial subependymoma in a 31-year-old male patient presenting with headache, nausea and vomiting as well as gait disturbances. Although most supratentorial subependymomas have distinctive MR features, our case demonstrated imaging findings that made it indistinguishable from other more aggressive malignant supratentorial intraventricular lesions. It is of paramount importance to consider supratentorial subependymomas in the differential diagnosis of supratentorial lesions, even if their radiological features were atypical.

Anaplastic supratentorial cortical ependymoma presenting as a butterfly lesion

BACKGROUND

Anaplastic cortical ependymomas are rare lesions with few cases reported in the literature.

CASE DESCRIPTION

We present a unique case of an anaplastic cortical ependymoma in a 51-year-old female presenting as a butterfly lesion with involvement of both frontal lobes. The patient underwent gross total resection of her tumor with further adjuvant treatment. We present the findings in our case and review the literature surrounding supratentorial ependymomas and their treatment outcomes.

CONCLUSION

Rarely, cortical ependymoma can present as a butterfly lesion and should be considered in the differential diagnosis of such lesions in adults.

Neuroimaging of pediatric posterior fossa tumors including review of the literature

Conventional, anatomical MRI is an essential tool for diagnosis and evaluation of location, quality, and extent of posterior fossa tumors, but offers limited information regarding tumor grade and type. Advanced MRI techniques such as diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI) may improve the specific diagnosis of brain tumors in the posterior fossa in children. In this review the conventional neuroimaging findings, as well as the DWI, and DTI characteristics of common pediatric posterior fossa tumors are discussed and summarized.

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.

Imaging of ependymomas: MRI and CT

The imaging features of intracranial and spinal ependymoma are reviewed with an emphasis on conventional magnetic resonance imaging (MRI), perfusion MRI and proton magnetic resonance spectroscopy, and computed tomography. Imaging manifestations of leptomeningeal dissemination of disease are described. Finally, salient imaging features obtained in the postoperative period to evaluate completeness of surgical resection, and thereafter for long-term surveillance for disease recurrence, are reviewed.

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.

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.

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.

Tratamiento del neurocitoma central. Experiencia en nuestro centro

Central neurocytomas are classically considered as a rare, intraventricular benign tumours with neuronal differentiation derived from precursor cells of subventricular matrix. However some patients with neoplasms with histologic atypia and elevated proliferation potential may have a poor outcome. Treatment of choice is complete surgical excision. Adjuvant therapy is reserved for patients with residual or recurrent lesions including reoperation, radiotherapy or chemotherapy. We review our experience with the treatment of this neoplasm. Five patients with an intraventricular mass studied with magnetic resonance imaging underwent craniotomy for tumour resection. All cases were reviewed retrospectively. Histopathological analysis confirmed central neurocytoma in all cases. Proliferation index was assessed by Ki-67 immunohistochemistry. Complete radiological tumor resection through transcortical approach was achieved in all except one patient. In this case adjuvant therapy with radiosurgery was given with important reduction in tumor size. All the tumours had a proliferation index below 2% except one with 5%. Follow-up in four patients ranged from 12 to 36 months. There were no tumour recurrences in this period. Complete surgical excision of central neurocytoma provides better local control and survival compared with other treatments. Radiosurgery as adjuvant therapy in incomplete resections may eliminate the need of reoperation and avoid long-term side effects from conventional radiotherapy.

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.

Cervical ependymoma presenting with brainstem and cerebellar signs: case report

This case report demonstrates cervical spinal cord pathology which presented with brainstem and cerebellar signs consequent to the peritumoural oedema that extended rostrally to the pontomedullary junction. A Medline search of the literature back to 1960 failed to produce any previous report of a cervical ependymoma presenting with brainstem and cerebellar signs purely consequent to oedema. This case highlights the need to look further afield when presented with the scenario of clinical features of a brainstem lesion with only oedema apparent on cranial imaging. It indicates the need to include cervical imaging well below the foramen magnum in these circumstances.

From the archives of the AFIP. Cerebral intraventricular neoplasms: radiologic-pathologic correlation

Intraventricular neoplasms are readily seen on cross-sectional images, but the myriad possibilities may make a focused differential diagnosis elusive. Consideration of the tissue within and composing the ventricular lining and the clinical findings provide the means to limit the differential diagnosis when analyzing an intraventricular mass on an imaging study. Ependymomas are typically calcified, are more common in children, are more common in the fourth ventricle, and show intense enhancement on contrast-enhanced images. Subependymomas and central neurocytomas have an affinity for the anterior portion of the lateral ventricle, and both commonly demonstrate a heterogeneous cystic appearance on cross-sectional images. Subependymomas are more common in older adults, whereas central neurocytomas are more common before 40 years of age. Subependymal giant cell astrocytomas always lie near the foramen of Monro and are characterized by frequent calcification, intense enhancement on contrast-enhanced studies, and the presence of other stigmata seen in tuberous sclerosis. When a mass is centered on the choroid plexus, a highly vascular tumor-either choroid plexus papilloma, choroid plexus carcinoma, meningioma, or metastasis-should be suspected. The characteristic heavily lobulated appearance of a choroid plexus tumor favors this diagnosis over other possibilities, although it is not always possible to distinguish between the more common benign form, the choroid plexus papilloma, and the less common malignant counterpart, the choroid plexus carcinoma. By using clinical, demographic, and imaging findings, one can significantly limit the differential diagnosis for many of the most common intraventricular neoplasms.

Tumours around the foramen of Monro: clinical and neuroimaging features and their differential diagnosis

The clinical and neuroimaging features of 20 patients with lateral ventricular tumours located around the foramen of Monro were reviewed retrospectively with special emphasis on the differential diagnoses. Histologic types were: eight neurocytomas, four subependymal giant cell astrocytomas (SGCAs), three subependymomas, two fibrillary astrocytomas, and one each of pilocytic astrocytoma, malignant astrocytoma and malignant teratoma. The mean age of the patients with neurocytoma was 29.6 years, with SGCA 13.3 years and with subependymoma 55.3 years. All tumours appeared nodular in shape, and on computed tomography (CT) neurocytomas were either isodense or highdense with the brain, while all subependymomas and SGCAs were lowdense. Calcification was observed in two SGCAs, and one neurocytoma. Five neurocytomas and all four SGCAs showed mild to moderate contrast enhancement, while all three subependymomas showed either no, or scarce, enhancement. Magnetic resonance imaging (MRI) studies were available in 10 patients, with the signal characteristics of four neurocytomas and three SGCAs being nonspecific, while two subependymomas were both hypointense on T1-weighted images and hyperintense on T2-weighted images. Thus important features for differential diagnosis included age of the patient and density on precontrast CT. In this series, either an extensive excision of the tumour or a partial removal, thus relieving the obstruction of the foramina of Monro, usually provided long term survival, with 18 patients surviving a mean of 10.8 years.

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.

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.

Symptomatic subependymomas of the lateral ventricles. Report of eight cases

Subependymomas are rare, slow-growing, benign intraventricular tumors, which often are asymptomatic and are discovered incidentally. The review of the literature shows more than 100 symptomatic cases, less than half located in the lateral ventricles. Here we report 8 cases of symptomatic subependymomas of the lateral ventricles, studied by CT and/or MR and treated by direct surgical approach. The suspicion of a subependymoma should arise when a patient older than 10-15 years with long clinical history presents an intraventricular tumor isodense on CT and isointense in T1 and hyperintense in T2 on MR, with scarce or discrete contrast enhancement. Surgical treatment is indicated in symptomatic subependymomas of the lateral ventricles and usually allows complete tumor removal. The prognosis is usually good, also without postoperative irradiation.

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.

Neuroradiology of central neurocytoma

Central neurocytomas (CN) are rare, usually benign cerebral intraventricular neuroepithelial tumors, which occur in adult patients. Retrospective evaluation of the CT- and MRI-findings in eight cases as well as review of the cases reported in the literature showed that CN usually presents as a primarily slightly hyperdense and/or hyperintense mass within the body of the lateral ventricle with moderate contrast enhancement. The majority of tumors contain both multiple small cysts and calcifications and exhibit a characteristic broad based attachment to the superolateral ventricular wall. We conclude that these criteria appear to be reliable to exclude other intraventricular tumors such as astrocytoma, giant cell astrocytoma, ependymoma, subependymoma, intraventricular oligodendroglioma and meningioma. Preoperative diagnosis of CN may prove of value for planning therapy, because this tumor type seems to have a better prognosis than other intraventricular tumors.

Tumors of the lateral ventricles

Tumors are only rarely found in the lateral ventricles. Although various oncotypes of these tumors differ in growth rate and invasiveness they present the same clinical pattern with the same diagnostic and surgical problems. Thus we can consider them as a group. This series comprises 51 primary tumors arising strictly from the structures of the lateral ventricles, the majority from the trigone, operated on between 1952 and 1988: 20 meningiomas, 19 ependymomas, 9 papillomas of the choroid plexuses, and 3 subependymomas. As most of these tumors were benign, the response to surgical treatment was, as other authors have found, good with permanent cure or long survival in the majority of cases. Advances in neuroradiological techniques have greatly facilitated the work-up and differential diagnosis of these tumors. Of the various surgical approaches, the parieto-occipital is preferred by our department, even for tumors of the dominant hemisphere. Our operative mortality of 10.6% tallies with that of other workers.

Malignancy criteria in computed tomography of primary supratentorial tumors in infancy and childhood

The CT findings of 11 malignant primary supratentorial tumors in children are compared with those of 38 benign tumors. The malignant tumors were more often laterally placed and surrounded by edema. Irregular tumor shape and high or "mixed" density were more frequent in the malignant group where larger tumor volume was found. The contrast enhancement pattern was also different. Thus, ring enhancement with central lucency was more often seen in the malignant tumors. Seven of the malignant tumors had both irregular shape and edema, while this combination was not present in any of the 38 benign tumors.