Tumors and approaches to the lateral ventricles. Introduction and overview

Comparative Analysis of Supratentorial Intraventricular Tumors in Adults and Pediatrics in a Developing Country: Clinicopathological Features, Surgical Management, and Outcomes

BACKGROUND

 Supratentorial intraventricular tumors, encompassing lateral and third ventricular tumors, are uncommon intracranial neoplasms, typically slow-growing and benign, manifesting symptoms only upon reaching a substantial size. This study aims to identify optimal surgical approaches, assess the prevalence and characteristics of these tumors, and evaluate postoperative outcomes among pediatric and adult age groups.

METHODS

 A retrospective comparative study at a tertiary care hospital from January 2014 to June 2020 included 165 patients (68 pediatrics, 97 adults) meeting inclusion criteria for intraventricular tumor management. Data covered demographic factors, clinical history, neurological assessments, neuroimaging, surgical approaches, histopathological diagnoses, immunohistochemical features, adjuvant therapies, follow-up status, postoperative complications, and morbidity/mortality.

RESULTS

 Ventricular tumor incidence showed male preponderance in both adults (M:F = 1.2:1) and pediatrics (M:F = 3:1). Lateral ventricles were the most common location. Pediatric cases exhibited more frequent calcifications on computed tomography scans (35.6% vs. 29.5%). Grade II and III tumors were more prevalent in adults within the lateral ventricle (27.1 and 1.9%) compared with pediatrics (6.5 and 8.4%). The third ventricle predominantly featured benign lesions, with pediatric patients experiencing significantly longer hospital stays (16.12 ± 21.94 days vs. 9.58 ± 6.21 days) (p = 0.006). Adults and pediatric patients showed a significant difference in high-grade lateral ventricle tumors (p-value = 0.002*).

CONCLUSIONS

 Supratentorial ventricular tumors are relatively more prevalent in children than adults, presenting challenges due to size and bleeding risks. Surgical resection is the primary treatment, with a focus on the optimal approach for gross total excision to reduce recurrence risk.

Intraventricular Tumors: Surgical Considerations in Lateral and Third Ventricular Tumors

Management of lateral and third ventricular tumors has been a challenge for neurosurgeons. Advances in imaging and pathology have helped in a better understanding of the treatment options. Technical refinement of microsurgical technique and addition of endoscopy has enabled more radical excision of tumors, when indicated, and added more safety.A proper understanding of the pathology at various ages and treatment options is continuously evolving. Many pediatric tumors are amenable to conservative surgical methods with effective complementary treatments. However, radical surgery is required in many adults as the main treatment and for many benign tumors. Various intraventricular lesions encountered and their surgical management is reviewed here for their efficacy, safety, and outcome, encompassing changes in our practice over the last 20 years.

Transcortical approaches to large intraventricular tumors: a prospective case series of 20 patients

Background

Large intraventricular tumors (IVTs) impose technical and surgical challenges, due to their enormous sizes, mass effect, vast extensions, and vascularity.

Objective

The authors aim at presenting their results, clinical outcomes, and the surgical strategies in the management of large IVTs through transcortical approaches.

Methods

A prospective trial was conducted at the Main Hospital of Alexandria University, Egypt, between August 2018 and October 2020 on 20 patients harboring IVTs larger than 5 cm or bilaterally represented. The variables evaluated included the extent of resection, postoperative neurological deficits, blood loss, surgical approaches, intraoperative challenges, complications, adjuvant therapies, Glasgow Outcome Scale, hydrocephalus, and cerebrospinal fluid (CSF) diversion.

Results

The study included 20 cases (9 males and 11 females). Mean age at diagnosis was 16.1 years (range 1–45). Mean follow-up was 12 months (range 9–26). Primary tumor locations were ventricular body, atrium, temporal horn, and frontal horn in 11, 5, 3, and 1 cases, respectively. Main pathologies were central neurocytomas (7 patients/35%), ependymomas (3 patients/15%), and subependymal giant cell astrocytoma (SEGA) (3 patients/15%). Excision was gross total (n = 19) and near-total (n = 1). Significant intraoperative bleeding (n = 6). Postoperative minor intraventricular hemorrhage (n = 6), subdural collections (n = 8), hydrocephalus (n = 9), memory affection (n = 4), and motor deficits (n = 4). Postoperative Glasgow Outcome Scale of 5/5 (n = 20), no mortalities were recorded. preoperative seizures (n = 7), new onset postoperative seizures (n = 2).

Conclusion

Surgical approaches to large tumors of the lateral ventricles should be tailored to the variability of tumor locations, dimensions, extensions, and the individual morbid anatomy, in addition to the surgeon’s experience and preferences. Trans-cortical approaches can provide safe surgical corridors to tackle these challenging subtypes of IVTs with good clinical outcomes, tumor resectability rates, and seizure control.

Resection of intra- and paraventricular malignant brain tumors using fluorescein sodium-guided neuroendoscopic transtubular approach

BACKGROUND

The requirement of brain retraction and difficulty in distinguishing the tumor demarcation are challenging in conventional approaches to intra- and paraventricular malignant tumors (IV-PVMTs). Tubular retractors can minimize the retraction injury, and fluorescein-guided (FG) surgery may promote the resection of tumors. Our aim is to evaluate the feasibility, safety, and effectiveness of fluorescein-guided endoscopic transtubular surgery for the resection of IV-PVMTs.

METHODS

Twenty patients with IV-PVMTs underwent FG endoscopic transtubular tumor resection. Fluorescein sodium was administered before the dural opening. The intraoperative fluorescence staining was classified as "helpful" and "unhelpful" based on surgical observation. Extent of resection was assessed using postoperative magnetic resonance imaging. Karnofsky Performance Status (KPS) score was used to evaluate the general physical condition of patients.

RESULTS

There were 9 glioblastomas, 4 anaplastic astrocytomas and 7 metastatic tumors. "Helpful" fluorescence staining was observed in 16(80%) of 20 patients. Gross total resection was achieved in 16(80%) cases, near-total in 3(15%) cases, and subtotal in 1 (5%) case. No intra- or postoperative complications related to the fluorescein sodium occurred. The median preoperative KPS score was 83, and the median KPS score 3-month after surgery was 88.

CONCLUSION

FG endoscopic transtubular surgery is a feasible technique for the resection of IV-PVMTs. It may be a safe and effective option for patients with these tumors. Future prospective randomized studies with larger samples are needed to confirm these preliminary data.

Tumors of the lateral and third ventricle: surgical management and outcome analysis in 42 cases

Objectives:

To discuss the clinical presentation, pathological diagnosis, and surgical outcome for a series of 42 consecutive patients treated for lateral and third ventricular tumors.

Methods:

This is a retrospective series study conducted between 2001 and 2015 and included 42 patients (mean age: 25 years; range: 2 months-65 years) with lateral and third ventricle tumors surgically treated at King Khaled University Hospital, Riyadh, Kingdom of Saudi Arabia. Demographic, clinical, radiological, surgical, histopathological, and follow up data were analyzed.

Results:

The most common symptoms at presentation included headache (69%), nausea/vomiting (38%), visual deficits (24%), and seizures (17%). Lesions were located in the lateral ventricle in 15 patients, third ventricle in 20 patients, and involved both the lateral and third ventricles in 7 patients. The most common tumor types in the overall cohort were colloid cysts (n=6) and pineal tumors (n=6). The postoperative complication rate was 36%. The most common postoperative complications were seizure and hydrocephalus (n=5 each, 12%). Surgical mortality was 5%.

Conclusion:

The selection of the surgical approach for intraventricular tumor resection is fundamentally dependent on the surgeon’s experience and preference. We recommend that this decision be based on the anatomic considerations that provide the best and safest access to the mass, rather than on the risk of seizure following transcortical approach.

Cognitive function assessment and comparison on lateral ventricular tumors resection by the frontal transcortical approach and anterior transcallosal approach respectively in children

Currently, there are few studies on cognitive impairment caused by neurosurgery, and there have been no studies on cognitive impairment after resection of lateral ventricular tumors in children. Previously, our research team has reported that the frontal transcortical approach can impair cognitive function. In this study, we explored which functions would be damaged by the transcallosal approach and compared the cognitive function changes caused by the two surgical approaches, so as to provide a theoretical basis for the selection of pre-operative surgical approaches. The authors prospectively collected pediatric patients with lateral ventricular tumors who had undergone surgical resection through the frontal transcortical approach and anterior transcallosal approach in Beijing Tiantan Hospital from November 2012 to May 2017. The inclusion criteria according to the Children Wechsler Scale requirements and clinical performance were formulated. Wechsler Intelligence Scale for Children®-fourth edition: Chinese version (WISC-IV) was adopted for general intelligence and cognitive function assessment in the study. In addition, the resting-state functional magnetic resonance imaging (resting-state fMRI) and diffusion tensor imaging (DTI) were carried out to measure the level of co-activation and to explore the functional connectivity between the brain regions at the pre-operative period and 6-month follow-up in post-operation. A total of 30 patients were enrolled. Gross total resection was achieved in all patients, and no severe post-operative complications were observed. The frontal transcortical approach was applied in 19 patients, and the transcallosal approach was conducted for 11 patients. Compared with the pre-operative indices of WISC-IV, patients generally had a lower level of indices of the WISC-IV in post-operation. In patients accepting lateral ventricular tumors resection through the anterior transcallosal approach, the total IQ was declined to M = 84.82, SD = 8.072 from M = 93.27, SD = 6.635 within the 6-month convalescence. The data of working memory (t = - 2.990, p = 0.002) and total IQ (t = - 2.205, p = 0.028) pre- and post-operative showed statistical significance. But in the comparison of two surgical approaches, it was found that IQ had no statistical difference in WISC-IV tasks data. Previous studies suggest that the frontal transcortical approach impair perceptual reasoning, processing speed, and IQ, while this study indicates that the anterior transcallosal approach impairs patients' working memory and IQ. Both approaches make equal damage to IQ. Through comparing the two surgical approaches, it can be known that the anterior transcallosal approach cannot replace the frontal transcortical approach. The protection of cognitive function should be considered as one of the bases for neurosurgeons to select the operative approach before the operation. However, in an actual situation, the specific approach should be carefully selected by comprehensive consideration.

Cognitive performance change of pediatric patients after conducting frontal transcortical approach to treat lateral ventricular tumor

OBJECTIVE

Applying frontal transcortical approach to treat lateral ventricular tumor is one of the most common neurosurgical manipulations. The frontal transcortical approach generally passes through the middle frontal gyrus in which there is no major function involved in the traditional sense. However, current researches have suggested that the prefrontal cortex (PFC) plays a central role in the whole network of the brain cognitive frame. In addition, cognitive function is crucial in growing and developmental stages and essential for the educational achievement, especially for children. Based on this, the authors in this study analyzed cognitive performance change of pediatric patients who had accepted frontal transcortical operation in 1-year follow-up and discussed the possibility of higher cognitive functions of the damaged region.

PATIENTS AND METHODS

In this single-center study, 15 pediatric patients (median age at surgery, 9.21 years old; range, 6.42-14.17 years old) who had been treated with frontal transcortical approach for lateral ventricular tumors were selected as research objects. The cognitive function assessment was conducting by adopting the revised Wechsler Intelligence Scale for Children-fourth edition (WISC-IV). In addition, the resting-state functional magnetic resonance imaging (resting-state fMRI) and diffusion tensor imaging (DTI) were carried out to measure the level of co-activation and to explore the functional connectivity between the brain regions at the preoperative period and 1-year follow-up after surgery.

RESULTS

GTR was achieved in all patients, and all patients were in good condition after surgery. Compared to the preoperative indices of WISC-IV, patients generally had a lower level of indices of the WISC-IV after surgery, for example, the total IQ was declined to M = 83.60, SD = 9.500 from M = 95.33, SD = 13.844 within 1 year convalescence. The data of perceptual reasoning (t = - 2.392, p = 0.016), processing speed (t = - 2.121, p = 0.033), and total IQ (t = -2.638, p = 0.008) before and after surgery showed statistically significance. Furthermore, decreased functional connectivity and disconnected neural fasciculus were revealed by the size of activation regions in the resting-state fMRI and the reconstruction of three-dimensional images of white matter tracts in the DTI pre- and post-operative.

CONCLUSION

The PFC was not regarded as a major functional area in the past, but the researches at present have shown that the interactions between PFC and other posterior brain regions serve as the basis of the higher cognitive functions. According to imaging manifestations and WISC-IV tasks in this paper, we found that the PFC injury caused by the frontal transcortical approach led to damaged brain structure and impaired the performance of cognitive function. On this basis, we detected that the perceptual reasoning and processing speed maybe have more extensive connections with the middle frontal gyrus.

Pilocytic astrocytoma: A rare presentation as intraventricular tumor

Background:

Pilocytic astrocytoma (PA) is the most prevalent central nervous system (CNS) tumor in pediatric population and accounts for an approximate of 5–6% of all gliomas. This neoplasm can occur at all levels of the neuraxis, with majority (67%) arising in the cerebellum and optic pathway. PAs are World Health Organization Grade I tumors and are the most benign of all astrocytomas characterized by an excellent prognosis. Other differentials include subependymal giant cell astrocytoma (SEGA), ependymoma, meningioma, and low-grade gliomas such as pilocytic or diffuse astrocytoma; calcification is more commonly regarded as a feature of benign or slow-growing tumors.

Case Description:

We present a case of a 17-year-old female presenting with an unusual cause of hydrocephalus, a rare case of a calcified pilocytic astrocytoma as an intraventricular tumor.

Conclusion:

PA rarely presents as an intraventricular tumor and should be included in the differential diagnosis of a large mass with massive intratumoral calcification.

Microsurgical resection of tumors of the lateral and third ventricles: operative corridors for difficult-to-reach lesions

Tumors of the lateral and third ventricles are cradled on all sides by vital vascular and eloquent neural structures. Microsurgical resection, which always requires attentive planning, plays a critical role in the contemporary management of these lesions. This article provides an overview of the open microsurgical approaches to the region highlighting key clinical perspectives.

Thalamic arteriovenous malformation fed by the artery of Percheron originating from the contralateral posterior cerebral artery in a child

PURPOSE

Artery of Percheron (AOP) is a rare variant of thalamoperforating artery with a single common trunk feeding both thalami and with or without contribution to the rostral midbrain. We report the first case of thalamic arteriovenous malformation (AVM) fed by AOP with hemorrhagic onset.

METHODS

A 12-month-old girl suddenly weakened and developed coma. Left thalamic hemorrhage was detected with the third and both lateral ventricles' hematoma. Thalamic AVM was discovered to be fed by an AOP originating from the contralateral posterior cerebral artery.

RESULTS

Endovascular embolization of AVM was impossible due to a risk of bilateral thalamic infarction and anatomical inaccessibility. Thalamic AVM was removed by high superior parietal approach without new neurological symptoms.

CONCLUSION

The first case of thalamic AVM fed by AOP originating from the contralateral posterior cerebral artery is reported. Surgical removal of AVM would be at the heart of treatment in order to avoid bilateral thalamic infarction.

[Liponeurocytoma in the left lateral ventricle. Presentation of the first case reported in Spain and literature review]

Supratentorial liponeurocytoma is a rare tumor, predominantly appearing in young males. It most commonly affects the lateral ventricles, with involvement of the third ventricle being exceptional. It is defined as a low-grade neuroglial tumor, with areas of associated lipomatosis. The most common clinical manifestation is that resulting from the presence of secondary intracranial hypertension and hydrocephalus. We present the first case reported in Spain of this tumor type and one of the few appearing in the literature so far. We report the case of a 33-year-old male patient, suffering from crural sensitive symptoms and recent onset headache. The radiographic study revealed the presence of a large supratentorial tumor; intraventricular, multicystic, heterogeneous and with areas of associated lipomatosis. The patient underwent surgery and complete tumor resection was achieved. The definitive diagnosis was of supratentorial liponeurocytoma. The presence of a supratentorial intraventricular tumor with areas of fatty degeneration should lead us to consider this type of tumor in the differential diagnosis. Complete tumor resection is considered to be the treatment of choice.

Outcomes after surgery for central neurocytoma: results of a French multicentre retrospective study

OBJECTIVE

Central neurocytoma (CN) is a rare intraventricular tumour. Surgery has been highly recommended for CN, although it entails a significant chance to harm the patient. We aimed to provide new data that would support surgical decision-making and optimise patient information about outcomes after surgery.

METHOD

Under the auspices of the French Society of Neurosurgery, we conducted a multi-institutional database search in 23 academic hospitals. In all, we reviewed the relevant clinical and radiological data of 82 patients who were operated on for CN between 1984 and 2008, and had their diagnosis confirmed by central pathological review.

RESULTS

The median follow-up was 61 months (range, 6-96 months). Gross total resection (GTR) was achieved in 48 % of the patients, and subtotal resection (STR) in 52 %. The 5-year overall survival rate was 93.8 % (95 % CI, 93.7-93.9). The 5-year progression-free survival rate was 92.1 % (95 % CI, 91.90-92.2) in patients who underwent GTR, compared with 55.3 % (95 % CI, 55.1-55.5) in patients who had STR (p = 0.01). The overall perioperative complication rate was 66 %. The main causes of postoperative disability were some degree of postoperative paresis and/or aphasia (39 %), memory difficulties (29 %) and temporary hydrocephalus (26 %). GTR was not associated with an increased rate of postoperative complications compared with STR. At last follow-up, Karnofsky Performance Score was at least equal to 80 for 90.6 % of the tested patients.

CONCLUSION

Our series emphasised that maximal surgical resection of CNs offers favourable benefit-risk ratio. These data are of importance to properly counsel patients regarding expected outcomes, and to plan relevant preoperative and postoperative investigations like language and memory function evaluation.

Surgical anatomy and surgical approaches to the lateral ventricles

This study focuses on the surgical approaches to intraventricular tumors which have developed within the cavity of the lateral ventricle. The first section is dedicated to embryology and describes the wrapping of the telencephalic vesicles around the thalamus and the morphogenesis of basal nuclei and commissures. In the second section, the anatomy of the lateral ventricles is described, along with their arterial and venous vasculature, their relationship with the eloquent cortical areas and cortical sulci, and their relationship with white matter fascicles, especially the optic radiations. In the third part, the main surgical approaches to the frontal horn, to the ventricular atrium and to the temporal horn are detailed.

Intraventricular glioblastoma multiforme with previous history of intracerebral hemorrhage : a case report

GBM is the most common primary brain tumor, but intraventricular GBM is rare and only few cases have been reported in the literature. The authors report a case of 64-year-old man who had a remote history of previous periventricular intracerebral hemorrhage. Brain computed tomography (CT) and magnetic resonance (MR) imaging showed an intraventricular lesion with inhomogeneous enhancement, infiltrative borders and necrotic cyst, and obstructive hydrocephalus. The patient underwent surgical removal through transcortical route via the bottom of previous hemorrhage site and the final pathologic diagnosis was GBM. We present a rare case of an intraventricular GBM with detailed clinical course, radiological findings, and pathological findings, and the possible origin of this lesion is discussed.

Transcallosal transchoroidal approach to tumors of the third ventricle

Although the literature is rich with descriptions of the approach to the third ventricle, surgeons remain cautiously reserved. In this report, we demonstrate that the transcallosal approach can be easily performed provided that preoperative planning is adequate. Familiarity with the course of major cortical and deep draining veins grants the surgeon a wide exposure of the posterior third ventricle. We discuss the indications, surgical technique, and pitfalls to this approach while providing an accompanying video mirroring our discussion.

Lateral Ventricle Tumors: Surgical Strategies According to Tumor Origin and Development— A Series of 72 Cases

OBJECTIVE:

Optimal surgical management in lateral ventricle tumors remains controversial. We conducted a retrospective study of patients with these lesions treated with a surgical strategy on the basis of tumor origin: primary or secondary ventricular and associated transependymal development.

METHODS:

A total of 72 patients underwent surgery for lateral ventricle tumors. The mean patient age was 39 years (range, 6 mo to 78 yr). Raised intracranial pressure occurred in 53% of patients, followed by mental disturbances or psychiatric symptoms (32%) and motor deficits (21%). The transcortical approach was used in 44 patients, and an interhemispheric approach was used in 28 patients; a transcallosal approach was used in 16 patients, and a parasplenial approach was used in 12 patients. Neuropsychological tests were performed in selected patients.

RESULTS:

Total resection was performed in 82% of patients. Sixty-five percent of tumors were benign and low-grade tumors. There was no surgical mortality, and the morbidity rate was 11%. Postoperative epilepsy (5.9%) was significantly increased in the transcortical group. The mean follow-up period was 55 months; 59% of patients achieved good recovery and moderate disability. In postoperative neuropsychological testing sessions, deficits in verbal memory were observed in six patients (8%). Final morbidity correlated well with preoperative clinical condition and pathological diagnosis.

CONCLUSION:

Lateral ventricle tumors can be treated best by careful selection of the approach according to tumor origin and development. Overall, the transcallosal approach is preferred, but in patients with transependymal growth or large primary or secondary ventricular tumors, the transcortical is a better option.

Clinicopathological study of seven cases of symptomatic supratentorial subependymoma

Subependymomas are rare, slow-growing tumors, the majority of which are found incidentally at postmortem examination. The authors retrospectively analyzed seven cases of symptomatic supratentorial subependymomas. Five were females and two were males, ranging in age at operation of 6-50 years (median 45). The follow-up period ranged from 1.5 to 8.3 years. Tumors were intraventricularly located as a lobulated mass with cystic changes: four in the frontal horn, two in the trigone, and one in the third ventricle. Moderate to marked enhancement was noted in two tumors of the trigone and in one tumor of the frontal horn on both CT scan and MR imaging. MR spectroscopy of a recurrent subependymoma demonstrated a higher Cho/Cr ratio of 2.66, compared with a Cho/Cr ratio (0.48) of a non-recurrent subependymoma. Angiography, which was performed in four patients, revealed no staining in two and delayed modest staining in two. Radiosurgery was performed in two patients but was ineffective. Five patients with gross total tumor resection showed no evidence of tumor recurrence to the last follow-up. The two subtotally resected trigonal tumors progressed two years after operation. No histological difference except MIB-1 index was noted between recurrent and non-recurrent cases. In conclusion, we suggest that subependymoma could show progressive biological behavior, especially in cases of markedly enhancing, irregularly contoured, large tumors located in the trigone. For symptomatic supratentorial subependymomas, gross total resection is the treatment of choice and radiation has little effect on tumor control.

Intracranial ependymoma

OBJECT

An intracranial ependymoma is a relatively rare but very interesting variety of glioma. In this paper, the authors compiled a review of the pathological features, imaging characteristics, and treatment strategies related to this brain tumor.

METHODS

A Medline search was conducted using the term "ependymoma." The bibliographies of papers obtained were also checked for articles and chapters that could provide additional understanding of this tumor. Malignant ependymomas and ependymomas of the spinal cord (including myxopapillary ependymomas) were excluded from this review.

CONCLUSIONS

The posterior fossa is the most frequent site for an intracranial ependymoma. Children are frequently affected. Most authors recommend resecting as much of the tumor as is safely possible. Microscopically, ependymal tumors show both epithelial and glial features. Glial fibrillary acidic protein immunohistochemistry, therefore, helps in identifying ependymomas. Because ependymomas often recur despite surgical intervention, radiotherapy and/or radiosurgery may also play an important role in their treatment. The use of chemotherapy in the treatment of these tumors, especially in the very young, is still being studied.

Transcallosal approach for tumors of the lateral and third ventricles

Tumors that arise within the ventricles present a unique surgical challenge. Because of their deep location, relatively large size, and their association with hydrocephalus, surgical planning requires a careful assessment of the optimal method to access the lesion and to provide adequate exposure for tumor resection. The transcallosal approach to the lateral ventricles often is the best procedure by which to achieve these goals.

Partial sectioning of the corpus callosum does not cause significant neurological deficits; however, if the surgery induces additional brain injury, the neurological deficits can be more severe in the presence of a callosotomy. Knowledge of the techniques of transcallosal surgery and careful preoperative planning can reduce the risk of permanent neurological impairment; these range from protection of the cortical veins that drain into the superior sagittal sinus to brain relaxation and ventricular drainage, as well as proper identification of anatomical landmarks within the ventricle. The transcallosal approach can offer a relatively easy access to the lateral and third ventricles, and with proper planning it can reduce the morbidity associated with resection of lesions within these compartments.

Pediatric supratentorial intraventricular tumors

A variety of mass lesions can arise within or in proximity to the ventricular system in children. These lesions are relatively uncommon, and they present a unique diagnostic and surgical challenge. The differential diagnosis is determined by tumor location in the ventricular system, clinical presentation, age of the patient, and the imaging characteristics of the lesion. In this report the authors provide an introduction to and an overview of the most common pediatric supratentorial intraventricular tumors. The typical radiographic features of each tumor and location preference within the ventricular system are reviewed. Management and treatment considerations are discussed. Examination of tissue samples to obtain diagnosis is usually required for accurate treatment planning, and resection without adjuvant therapies is often curative. The critical management decision frequently involves determining which lesions are appropriate for surgical therapy. Care ful preoperative neuroimaging is extremely useful in planning surgery. Knowledge of the typical imaging characteristics of these tumors can help to determine the diagnosis with relative certainty when a tissue sample has not been obtained, because a small subset of these lesions can be managed expectantly.