Search

Background: The management of lateral ventricle tumors requires a balance between maximizing safe resection and preserving neurological function., Method: The authors present a successful case of a left lateral ventricular central neurocytoma resection. The trans-superior frontal sulcus approach was employed, providing a safe corridor while minimizing damage to the surrounding neuroanatomy. The use of an endoscope further facilitated the procedure, enabling the confirmation of complete tumor removal and the preservation of deep venous drainage and periventricular structures., Conclusion: This case highlights the utility of the trans-sulcal approach and the benefits of endoscopic assistance in the management of lateral ventricle tumors., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: Intraventricular meningioma (IVM) is a rare subtype of intracranial meningioma, accounting for 9.8 to 14% of all intraventricular tumors. Currently, there is no clear consensus on which patients with IVM should receive conservative treatment, surgery, or stereotactic radiosurgery (SRS). This research aims to analyze the outcomes, including survival and recurrence rates of patients who undergo SRS for IVM as a primary or adjuvant treatment., Methods: A systematic search was conducted in Scopus, Web of Science, PubMed, and Embase till June 5th 2023. Screening and data extraction were performed by two independent authors. Random-effect meta-analysis was performed to determine the tumor control proportion of IVM cases treated with SRS. Individual patient data (IPD) meta-analysis was performed for the progression-free survival (PFS) of the patients in the follow-up time. All analyses were performed using the R programming language., Results: Out of the overall 132 records, 14 were included in our study, of which only 7 had enough data for the meta-analysis. The tumor control proportion was 0.92 (95% CI, 0.69-0.98) in patients who underwent SRS for primary IVM. The overall tumor control in both primary and adjuvant cases was 0.87 (95% CI, 0.34-0.99). the heterogeneity was not significant in both meta-analyses (P = 0.73 and P = 0.92, respectively). Post-SRS perifocal edema occurred in 16 out of 71 cases (0.16; 95% CI, 0.03-0.56), with no significant heterogeneity (P = 0.32). IPD meta-analysis showed a PFS of 94.70% in a 2-year follow-up. Log-rank test showed better PFS in primary SRS compared to adjuvant SRS (P < 0.01)., Conclusions: According to this study, patients with IVM can achieve high rates of tumor control with a low risk of complications when treated with SRS, regardless of whether they have received prior treatment. Although SRS could be a promising first-line treatment option for asymptomatic IVM, its efficacy in symptomatic patients and its comparison with resection require further investigation., (© 2024. The Author(s).)

Background: Ependymomas in the fourth ventricle in adults are rare entity. Surgical treatment of adult ependymomas is the only treatment modality since no other effective alternative is available. Radical resection often means cure but it is hindered by the nature and location of the lesion., Methods: Technical aspects of the fourth ventricle ependymoma surgery in adults are discussed. Anatomy of the area is provided with the step-by-step surgical algorithm., Conclusion: Radical resection of low-grade ependymoma with a detailed understanding of the anatomy in this area is vital considering the high effectiveness of the treatment and its excellent prognosis., (© 2024. The Author(s).)

Background: Supratentorial intraventricular tumors (SIVTs) are rare lesions of various entities characteristically presenting with hydrocephalus and often posing a surgical challenge due to their deep-seated localization. We aimed to elaborate on shunt dependency after tumor resection, clinical characteristics, and perioperative morbidity., Methods: We retrospectively searched the institutional database for patients with supratentorial intraventricular tumors treated at the Department of Neurosurgery of the Ludwig-Maximilians-University in Munich, Germany, between 2014 and 2022., Results: We identified 59 patients with over 20 different SIVT entities, most often subependymoma (8/59 patients, 14%). Mean age at diagnosis was 41 ± 3 years. Hydrocephalus and visual symptoms were observed in 37/59 (63%) and 10/59 (17%) patients, respectively. Microsurgical tumor resection was provided in 46/59 patients (78%) with complete resection in 33/46 patients (72%). Persistent postoperative neurological deficits were encountered in 3/46 patients (7%) and generally mild in nature. Complete tumor resection was associated with less permanent shunting in comparison to incomplete tumor resection, irrespective of tumor histology (6% versus 31%, p = 0.025). Stereotactic biopsy was utilized in 13/59 patients (22%), including 5 patients who received synchronous internal shunt implantation for symptomatic hydrocephalus. Median overall survival was not reached and did not differ between patients with or without open resection., Conclusions: SIVT patients display a high risk of developing hydrocephalus and visual symptoms. Complete resection of SIVTs can often be achieved, preventing the need for long-term shunting. Stereotactic biopsy along with internal shunting represents an effective approach to establish diagnosis and ameliorate symptoms if resection cannot be safely performed. Due to the rather benign histology, the outcome appears excellent when adjuvant therapy is provided., (© 2023. The Author(s).)

Background: The trans-eyebrow supraorbital keyhole approach, a minimal transcranial approach, has been widely used in different types of surgery for sellar and parasellar lesions. In this study, we investigated the outcome of this approach in the surgical treatment of suprasellar and third ventricular craniopharyngioma., Methods: Twenty-seven patients with suprasellar and third ventricular craniopharyngioma underwent surgery via a supraorbital approach between June 2007 and June 2018. The medical data and follow-up results were retrospectively analyzed., Results: All tumors were located in the suprasellar region and the third ventricle. The mean tumor size was 29.1 mm. The mean follow-up period was 49.6 months. Gross total resection (GTR) was achieved in 23 patients (85.2%). Of 17 patients with preoperative visual impairment, 12 patients (70.6%) showed improvement. Following surgery, 11 patients exhibited new-onset anterior hypopituitarism, ten developed diabetes insipidus, and two became overweight. One residual tumor relapsed 1 year after surgery. No perioperative death, cerebrospinal fluid (CSF) rhinorrhea, or meningitis occurred. All patients exhibited satisfactory cosmetic results. At the last follow-up, the Extended Glasgow Outcome Scale Score was 8 in 25 patients (92.6%)., Conclusion: The supraorbital trans-eyebrow keyhole approach is characterized by minimal invasion and a satisfactory cosmetic outcome. According to our experience, craniopharyngiomas located in the suprasellar region and the third ventricle can be safely resected via a trans-eyebrow supraorbital keyhole approach.

Tanycytic ependymoma is a rare subtybe of ependymoma with a predilection for the spinal cord and intracranial tanycytic ependymoma is thus extremely rare. Most studies on intracranial tanycytic ependymomas included only one or two cases. Here we report nine patients with pathologically confirmed intracranial tanycytic ependymomas. The clinical characteristics, including radiological and histological examination, operative records, and prognoses were reviewed. The case series included six male and three female patients with an average age of 19.3 years. Tumors were located in the lateral ventricle (3/9), the fourth ventricle (2/9), and the supratentorial extraventricle (4/9). Gross total resection (GTR) of the tumor was achieves in seven cases, and subtotal resection (STR) was achieved in the other two cases. One patient died 21 months after discharge. The left eight patients showed improved symptoms after surgery, and no tumor recurrence was found in these cases during the follow-up. It seems that intracranial tanycytic ependymoma has the best long-term prognosis compared to the other two subtypes of ependymoma. According to our experience, we recommend surgery including GTR and STR followed by radiotherapy for patients with intracranial tanycytic ependymomas.

Post-operative pediatric cerebellar mutism syndrome (PPCMS) is a clinical syndrome arising from cerebellar injury and characterized by absence of speech and other possible symptoms and signs. Rare reports described some benefit after administration of dopamine agonist therapy, but no treatment has proven efficacy. In this paper, we report on the dramatic, sudden resolution of PPCMS induced by midazolam administration in a boy who underwent posterior fossa surgery for choroid plexus papilloma of the fourth ventricle. In addition to clinical improvement, post-midazolam single-photon emission computed tomography also demonstrated amelioration of brain perfusion.

Ependymomas are rare neuroepithelial tumors which may arise anywhere along the ventricular system. Tumors arising in the fourth ventricle present unique challenges. Complete tumor resection favors prolonged survival, but may result in inadvertent injury of surrounding neural structures-such as cranial nerve (CN) nuclei. Here, our institutional experience with surgical resection of fourth ventricular ependymomas is described. A single institution, retrospective analysis of consecutive case series of adult surgically resected fourth ventricular ependymomas with the bilateral telovelar approach. Extent of resection, outcomes and postoperative complications are statistically analyzed. From January 2000 to April 2016, 22 fourth ventricular ependymomas underwent surgical resection. Gross total resection was achieved in 18 of 22 cases (82 %). There were six postoperative CN palsies-3 lower CN palsies (IX, X, or XI), 1 CN VII palsy, 1 CN IV palsy, and 1 CN VI palsy. No deaths or cerebellar mutism occurred. Two of 6 CN deficits resolved and the rate of permanent neurologic deficit was 18 %. A CN deficit was not statistically associated with prolonged hospital stay or functional outcome. With exception of one patient, all patients functionally improved or remained unchanged following surgery. Postoperative complications included one wound infection (4.5 %) and four pseudomeningoceles (18 %). The rate of shunt-dependent hydrocephalus was 18 %. Tumors adherence to the fourth ventricular floor is not an absolute contraindication for complete resection. Intraoperative neuro-monitoring is essential, and the development of sustained, but not transient CN activity, and/or hemodynamically significant bradycardia should limit the extent of resection.

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., Competing Interests: Dr. Aaron Cohen–Gadol has a consulting agreement with Zeiss Meditec, the rest of the authors declare that they have no conflict of interest. Informed consent Informed consent was obtained from all individual participants included in the study.

Background: The "telo-velar" approach is an alternative to cerebellar splitting to gain access to the fourth ventricle through the so-called cerebello-medullary fissure (CMF)., Method: In this approach, the CMF is exposed and access to the ventricle is obtained by incising the tela chorioidea and inferior medullary velum. This approach enables the exploration of the entire ventricle cavity from the obex to the aqueduct., Conclusions: The exposure of the fourth ventricle is satisfactory and the floor of the fourth ventricle can be visualised early and protected. The extent of resection and outcome are satisfactory in most patients, including those with large tumours or lesions attached to the lateral or superolateral recesses of the ventricle. The deep rostral tumour attachment is the main limitation of the telo-velar approach., Key Points: • Early exposure of the interface lesion-floor of the fourth ventricle favours a safer tumour dissection. • We feel that resection of tonsils is not necessary in the surgical setting. • The posterior arch of C1 should be removed only if the tonsils are below the level of the foramen magnum. • The improved access to the lateral recess of the ventricle makes the telo-velar approach particularly effective in lesions attached to cerebellar peduncles. • The wide dissection of the cerebello-medullary fissure and gentle tonsils retraction may prevent from the occurrence of cerebellar mutism or other major cerebellar dysfunctions. • Even the bilateral opening of the CMF does not result in cerebellar mutism if wide and cautious dissection, avoiding retraction and vascular injuries, is obtained. • The exposure of the fourth ventricle was satisfactory also in patients harbouring lesions attached to the lateral or even the superolateral recesses of the ventricle. • A deep rostral tumour attachment seems to be, at least in our experience, the main specific limitation of the telo-velar approach. • The risk of hydrocephalus can be reduced by opening of the fissure bilaterally, exposing the aqueduct, and by cisterna magna-fourth ventricle communication augmentation. • The EVD is taken in place for 48-72 h to prevent possible abrupt increase of the intracranial pressure and to favour wound closure.

Background: Pure aqueductal tumors (ATs) differ from pineal region and tectal/tegmental tumors in that they are epicentered within the aqueduct. Nevertheless, these tumors are rarely described as a separate type of tumor, and are often grouped with other lesions located in the same vicinity. The present multicenter study focuses on our experience treating patients with pure ATs., Methods: Data from three large tertiary centers was collected retrospectively, including presenting symptoms, treatment paradigm, surgical approaches, pathology, and outcome., Results: Between 1999 and 2013, 16 patients with AT were diagnosed and treated at the three tertiary centers. Ages at presentation ranged from 5.5 to 57 years. Thirteen patients presented with hydrocephalus-related symptoms, and two were identified incidentally. Thirteen patients underwent an endoscopic third ventriculostomy, and two of these underwent a simultaneous endoscopic biopsy (one grade II ependymoma, one non-specified low-grade glioma). Two others underwent shunt placement. Three patients underwent resection due to tumor progression. Pathologies included glioblastoma multiforme, glioneural tumor, and ependymoma grade II. All non-resected tumors remained stable or grew only minimally., Conclusions: ATs are a rare entities that usually present with obstructive hydrocephalus. Treatment includes primarily cerebrospinal fluid drainage (preferably via an endoscopic third ventriculostomy). Simultaneous endoscopic biopsy may be done in selected cases. Tumor resection should be reserved for growing tumors; the trans-fourth ventricular or trans-choroidal approaches are probably safer than other approaches used to reach the tectal region.

Background: Small soft ventricular tumors are good candidates for complete removal by a purely endoscopic technique. This approach is particularly interesting for lesions located in the posterior third ventricle and aqueductal lumen., Methods: We present our method of endoscospic aspiration through direct contact between the tumor and the working channel of a flexible scope., Results: Aspiration without the intermediate use of cannulas is safe and has proved to be effective in the apparently total or partial removal of three soft tumors of different pathologies located in the third ventricle or aqueductal lumen. In one case, a second neuroendoscopy a few months later to repeat endoscopic third ventriculostomy (ETV) offered a unique opportunity to observe the absence of the tumor and the restored anatomy., Conclusions: Neuroendoscopy provides a safe, effective way to radically resect small soft tumors in these troublesome locations and can be a valuable alternative to microsurgery.

Background: The transcallosal approach provides a direct corridor to the lesions lying in the third ventricle with distinct advantages over alternative routes, such as the possibility to use multiple corridors for tumor resection., Method: Here we present a personal perspective of the surgery of tumors of the anterior portion of the third ventricle using this approach., Conclusions: This approach requires the ability to move around many neurovascular, cortical, and white matter structures. Knowledge of regional anatomy and adherence to principles of microsurgery are basic requirements to obtain a favorable outcome.

Background: The transcerebellomedullary fissure (trans-CMF) approach is safe and effective. Nevertheless, previous research documented a few differences in the use of this approach with regard to the opening portion of the fissure and roof of the ventricle. Here, we present a series of patients with fourth ventricular lesions and our experience using the trans-CMF approach., Methods: Fifty patients who underwent the trans-CMF approach were analyzed. The tela choroidea was simply incised in 32 patients: 27 unilaterally and 5 bilaterally. Both the tela and inferior medullary velum were cut in 18 patients: 16 unilaterally and 2 bilaterally. Unless the tumor extended below the C1 level, C1 was preserved intact. Brainstem mapping (BSM) and corticobulbar tract (CBT) motor-evoked potential (MEP) monitoring were used., Results: Gross total removal was achieved in 41 (82 %) cases, and sub-total removal was achieved in 9 (18 %) cases. Two deaths occurred 1-2 months postoperatively because of pulmonary complications. Four patients developed temporary mutism, all of whom underwent the bilateral trans-CMF approach (this rate is significantly higher than that of the unilateral approach, P < 0.05). No permanent neurological deficit occurred., Conclusion: The trans-CMF approach provides excellent access to fourth ventricular lesions without splitting the vermis. The opening portion of the fissure and roof of the ventricle should be determined by the location, extension and size of the lesion. In most cases, the unilateral trans-CMF approach with only a tela choroidea incision is adequate; this procedure is mini-invasive and possibly prevents postoperative mutism.

Background: Surgical treatment of large exophytic chiasmatic/hypothalamic astrocytomas extending into the anterior third ventricle remains a challenging task for neurosurgeons. In particular, when the tumor extends from the chiasmatic region upward to the foramen of Monro, damage to the fornix and other neurovascular structures is a major concern., Objective: To describe the technique used in the transventricular preforniceal surgical approach to remove the superior and superoposterior part of the tumor in the third ventricle for treatment of exophytic chiasmatic/hypothalamic astrocytoma., Methods: The transventricular preforniceal approach was used in two cases of exophytic chiasmatic/hypothalamic astrocytoma. The approach is summarized in 4 procedures: 1) exposure of the anterior horn of the lateral ventricle by the transcallosal approach, 2) identification of the foramen of Monro and the fornix, 3) incision of the septum pellucidum or the wall of the lateral ventricle, in front of the columns of the fornix, and 4) removal of the tumor through the space between the anterior commissure and the columns of the fornix., Results: Because the tumor compressed the foramen of Monro posteriorly and stretched the space between the anterior commissure and the columns of the fornix, the posterosuperior part of the tumor in the third ventricle was successfully removed through the surgical corridor in front of the columns of the fornix. In both cases, tumors were successfully removed using this approach without damaging the fornix and the anterior commissure. Residual tumor was removed using an anterior interhemispheric translamina terminalis approach in a two-stage surgery., Conclusions: The transventricular preforniceal approach can be applied for removing the superior part of exophytic chiasmatic/hypothalamic astrocytomas, because the space between the anterior commissure and the fornix is stretched by the tumor, providing an appropriate surgical corridor.

Background: Open surgical approaches to intraventricular tumours are complex and challenging. Neuro-endoscopy, however, has enabled us to biopsy and resect small intraventricular tumours with potentially reduced morbidity. Nevertheless, suitable methods/ instrumentation for resection have limited the use of the endoscope. The authors report the utilisation of endoscopic ultrasonic aspirator in the resection of an intraventricular tumour. This technique was compared to another case that utilised conventional endoscopic techniques for removal of an intraventricular tumour., Methods: Using an endoscope, the third ventricle was entered and visualised, with the tumours clearly seen. Tumours were then either debulked via conventional or novel technique., Results: Using the conventional technique, tumour was removed with rongeurs via the flexible scope. Irrigation was needed to improve vision due to bleeding. Postoperative magnetic resonance imaging (MRI) confirmed good excision. Histology was reported as anaplastic ependymoma World Health Organization (WHO) Grade III. Utilising the novel technique, the tumour was also debulked uneventfully. Histology confirmed Grade 1 glioneuronal tumour. Postoperative MRI revealed a small residuum., Conclusions: To date, endoscopic resection of tumours has been limited by suitable tools. The advent of an ultrasonic aspirator that can be used down an endoscope increases the possibilities for such resections. This is the first reported case of endoscopic resection of an intraventricular tumour using this technique.

A 60-year-old man was admitted with slowly progressive dizziness. Cranial nerve evaluation found no abnormalities. Magnetic resonance imaging revealed a well-circumscribed mass with homogeneous enhancement located in the fourth ventricle. The patient underwent surgery for the removal of the tumor via the bilateral suboccipital approach. Subtotal removal of the tumor was achieved in a piecemeal fashion. Histological diagnosis was meningothelial meningioma. Fourth ventricular meningiomas are extremely rare. We reviewed the literature and discussed the features of fourth ventricular meningiomas.

A 33-year-old male presented with a headache. He had a history of a previous surgical procedure for excisions of cervical spine hemangioblastomas 13 years prior He had a family history of von-Hippel Lindau (VHL) disease, and a VHL mutation was identified. Brain magnetic resonance imaging showed enhanced mass lesions in both the third and right lateral ventricles as well as in the cerebellum. The lesion in the right lateral ventricle also had a cystic component. Two-staged resections of the tumors in the third and right lateral ventricles and ventriculo-peritoneal shunt were performed. A histopathological specimen was compatible with a hemangioblastoma. Supratentorial intraventricular hemangioblastomas are extremely rare. We reviewed the literature and discussed the features.

In this short case-illustrated review we aimed to analyse the possible nuances of hemifacial spasm (HFS) as the presenting symptom of a tumour of the fourth ventricle. The issue is remarkable since HFS can be secondary to a fourth ventricle tumour, even when no other neurological signs are reported. In addition, the possible presentation with only upper facial muscle involvement, as in the presented case, can be deceitful because this is characteristic of the benign and much more frequent "typical" form. Based on our intra-operative data and on the previously reported cases, we think that pathogenesis could be referable to the facial nerve nucleus involvement and that clinical nuances could be related to the specific somatotropy of the nucleus under the fourth ventricle floor that, as in our case, can be infiltrated by tumour. Resolution of the disorder can usually be obtained after the complete resection of the tumour that in the reported case resulted a subependymoma (WHO grade I), so far never described in literature associated with HFS.

Purpose: This study investigates retrospectively the clinical, neuroradiological, pathological and surgical evidence verifying the infundibulo-tuberal topography for craniopharyngiomas (CPs). Infundibulo-tuberal CPs represent a surgical challenge due to their close anatomical relationships with the hypothalamus. An accurate definition of this topographical category is essential in order to prevent any undue injury to vital diencephalic centres., Methods: A systematic review of all scientific reports involving pathological, neuroradiological or surgical descriptions of either well-described individual cases or large series of CPs published in official journals and text books from 1892 to 2011 was carried out. A total of 1,232 documents providing pathological, surgical and/or neuroradiological evidence for the infundibulo-tuberal or hypothalamic location of CPs were finally analysed in this study., Findings: For a total of 3,571 CPs included in 67 pathological, surgical or neuroradiological series, 1,494 CPs (42%) were classified as infundibulo-tuberal lesions. This topography was proved in the autopsy of 122 non-operated cases. The crucial morphological finding characterizing the tubero-infundibular topography was the replacement of the third ventricle floor by a lesion with a predominant intraventricular growth. This type of CP usually presents a circumferential band of tight adherence to the third ventricle floor remnants, formed by a functionless layer of rective gliosis of a variable thickness. After complete surgical removal of an infundibulo-tuberal CP, a wide defect or breach at the floor of the third ventricle is regularly observed both in the surgical field and on postoperative magnetic resonance imaging studies., Conclusions: Infundibulo-tuberal CPs represent a major topographical category of lesions with a primary subpial development at the floor of the third ventricle. These lesions expand within the hypothalamus itself and subsequently occupy the third ventricle; consequently, they can be classified as not strictly intraventricular CPs. A tight attachment to the hypothalamus and remnants of the third ventricle floor is the pathological landmark of infundibulo-tuberal CPs.

Rosette-forming glioneuronal tumor of the fourth ventricle (RGNT) is a rare condition, which previously has been described predominantly in middle-aged patients. There is limited experience with this kind of tumor in the elderly. Clinical, neuroimaging, and histological features of an example in a 70-year-old male who presented initially with vertigo are detailed and compared with published cases. Neuroimaging studies demonstrated a 4-cm cystic lesion in posterior fossa containing a 1-cm contrast-enhancing nodule on its lateral margin. The lesion was confined to the fourth ventricle and initially thought to be a hemangioblastoma until angiography clarified the minimal tumor vascularization. Gross total resection was achieved. Pathological examination showed a rosette-forming low grade tumor with a cell proliferation rate of 2% being consistent with RGNT. The postoperative course was uneventful and clinical symptoms resolved completely. There was no tumor recurrence after 2 years follow-up. We confirm that the rare and only recently characterized tumor entity of RGNT can also be found in elderly patients; furthermore, it can be associated with a benign course. The main differential diagnosis of RGNT resulting from CNS-imaging modalities in elderly patients are pilocytic astrocytoma and hemangioblastoma of the posterior fossa, which after metastasis are the most common primary adult intra-axial posterior fossa tumors. Therefore, a subtle preoperative radiological diagnosis is warranted and surgery should be performed by experienced hands to avoid neurological deterioration.

Background: Intracranial subependymomas are rare, slow-growing and usually non-invasive tumors. The aim of this study was to analyze our experience with the surgical treatment of intracranial subependymomas., Methods: Between 1991 and 2007, 11 patients with intracranial subependymomas had surgery in our institution. Mean age of the patients was 54.4 years (ranging from 40 to 85 years)., Results: Tumors were located in the fourth ventricle in seven patients and in the lateral ventricle in four patients. Most patients presented with symptoms related to intracranial hypertension and/or cerebellar signs and symptoms (headache: eight patients; dizziness: six patients; nausea: six patients; gait ataxia: four patients), one patient with cognitive decline and flattened affect, and one patient with a hemiparesis. Six patients presented with hydrocephalus, but only one needed a permanent cerebrospinal fluid (CSF) shunt. Complete removal of the tumor was possible in eight cases. Following surgery, only one patient experienced a permanent drop of his Karnofsky Performance Index (from 70 to 60). Median follow-up was 37 months. There were no true recurrences during follow-up. A second surgery was required 7 years after the first operation for progression of an incompletely resected tumor., Conclusions: Removal of symptomatic subependymomas can be performed safely. Prognosis is excellent after a complete resection. The potential for a surgical cure, low surgical complication rates and the risk of undertreatment of a more aggressive tumor together may justify surgery for asymptomatic lesions.

Rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle has been recognized as a new type of glioneuronal tumor. RGNTs are typically located in the infratentorial midline with involvement of the fourth ventricle. They occasionally involve the aqueduct and/or vermis. RGNTs of unusual anatomical sites or those with unusual findings have been reported. The present case reports describe RGNT of the fourth ventricle with bilateral olivary degeneration. It is important to accumulate imaging findings and biological behaviors of RGNTs given the limited number of cases.

Background: Implantation of 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) wafer for malignant glioma is not recommended in the case of surgical opening of the ventricular system during microsurgical tumor resection because the wafer material may dislocate from the resection cavity into the ventricular system and cause obstructive hydrocephalus. TachoSil is an adhesive collagen fleece used in different surgical disciplines that provides an air- and liquid-tight seal closing communications between the ventricular system and the resection cavity after tumor removal., Methods: Occlusion of ventricular defects with TachoSil after microsurgical glioma resection was performed in two patients with newly diagnosed and seven patients with recurrent malignant glioma prior to BCNU wafer implantation into the resection cavity. Early postoperative cranial computed tomography (CCT)/MRI and follow-up MRI at 3 months' intervals were performed with a median follow-up of 10.4 months., Results: The collagen fleece was identified as a linear structure hypodense/hypointense to white matter on postoperative CT/MRI separating the resection cavity from the ventricular lumen in all cases. In no case did early CCT/MRI or follow-up MRI reveal wafer material within the ventricular system. In no case did signs of obstructive hydrocephalus occur., Conclusion: Sealing of the ventricular system using a fibrinogen-coated collagen fleece effectively separates the resection cavity from the ventricular system and allows implantation of BCNU wafers into the resection cavity. No morphological evidence for wafer material dislocation into the ventricular system or obstruction of CSF pathways was found in nine patients who received 41 follow-up MRI over 10.4 months of follow-up.

Object: Endoscopic and stereotactic surgery have gained widespread acceptance as minimally invasive tools for the diagnosis of intracerebral pathologies. We investigated the specific advantages and disadvantages of each technique in the assessment of periventricular lesions., Method: This study included a retrospective series of 70 patients with periventricular lesions. Endoscopic surgery was performed in 17 patients (mean age, 37 years; range, 4 months-78 years) and stereotactic biopsy in 55 patients (mean age, 63 years; range, 23-80 years), including two patients who underwent both procedures., Results: Hydrocephalus was present in 13/17 patients in the endoscopic group (77%) and in 11/55 patients in the stereotactic group (20%). Diagnosis was achieved in all patients in the endoscopic group and in all but one patient in the stereotactic group, in whom histological diagnosis was obtained by endoscopic biopsy during a second operation. In the endoscopic group, additional procedures performed included ventriculostomy (2/17), cyst fenestration (3/17), endoscopic shunt revision (3/17) and placement of Rickham reservoirs or external cerebrospinal fluid drains (6/17). Adverse events occurred in one patient after endoscopy (chronic subdural hematoma) and in two patients after stereotactic surgery (one mild hemiparesis and one transitory paresis of the contralateral leg)., Conclusions: Endoscopic and stereotactic surgery have distinct advantages and disadvantages in approaching periventricular lesions. The advantages of endoscopy encompass the possibility to perform additional surgical procedures during the same session (e.g. tumour reduction, third ventriculostomy, fenestration of a cyst). The visual control reduces the hazard of injury to anatomical structures and allows for a better control of bleeding although there is a considerable blind-out in such situations. The advantages of stereotactic surgery include a smaller approach and precise planning of the trajectory. It is usually performed under local anaesthesia. Both methods provide a safe and efficient therapeutic option in periventricular lesions with low surgical-related morbidity.

Introduction: Young children with significant ventricular dilatation or large intracranial fluid spaces often have a very thin cortical mantle as a result of persistently raised intracranial pressure. This rim of cortex has a tendency to fall away from the dura into the cavity during and after intracranial surgery, due to the lack of support, once the pressure in the fluid cavity has been reduced. This can lead to tearing of cortical bridging veins and the formation of post-operative subdural haematomas., Methods: We describe a simple technique that attempts to prevent this phenomenon occurring using tissue glue. Once the craniotomy has been performed and the dura has been formally opened, tissue glue is applied to the underside of the dura around the edge of the wound, prior to corticotomy., Results and Conclusion: This results in the cortical mantle adhering to the undersurface of the dura and prevents the mantle from falling into the cavity either during the procedure or post-operatively.

Purpose: Diffusion tensor tractography provides useful information regarding the surgical strategy for brain tumors. The goal of the present study was to analyze relationships between visual field deficits and the locations of brain tumors compared with optic tracts as visualized by tractography, and compared with the calcarine fissure., Methods: Subjects comprised 11 patients with brain tumor in the occipital lobe or atrium of the lateral ventricle who underwent surgery between October 2006 and February 2009. Tumors were categorized as Type A, with almost all the optic tract in the occipital lobe or atrium of the lateral ventricle running close to and stretched by the brain tumor; and Type B, with the optic tract running at least partially distant to the brain tumor and remaining unstretched., Results: Those type A optic tracts that were laterally compressed by brain tumors (Cases 1-3) displayed hemianopsia after surgery. When the brain tumor was located rostro-medial to the calcarine fissure and optic tracts were compressed caudally by the tumor, lower quadrant hemianopsia remained after surgery (Cases 4, 5). In other cases, the visual field remained or improved to normal after surgery., Conclusion: The relationship between optic tracts or the calcarine fissure, and brain tumors in the occipital lobe or atrium of the lateral ventricle is related to visual field deficits after surgery. In particular, those Type A optic tracts that are compressed laterally show hemianopsia of the visual field after surgery.

Purpose: Pediatric colloid cysts (CC) have a congenital origin, and yet, there are very few studies focussing exclusively on their occurrence in the pediatric population. Pediatric CC has been associated with more aggressive clinical and radiological patterns than their adult counterparts. In this study, undertaken on children with anterior third ventricular CC, excised using the interhemispheric transcallosal approach, the characteristic clinicoradiological features and management options are studied., Methods: Five pediatric patients (aged 16 years or less; mean age 13.8 years; mean duration of symptoms:7.6 months) out of 38 patients with CC operated between 1995 to 2009 were included. The clinical manifestations included those of raised intracranial pressure (n = 4); exacerbation of occipital headache on reading (n = 1); secondary optic atrophy (n = 3); and, drop attacks (n = 1). On computed tomography scan, the cyst was hyperdense, enhancing in two patients and not enhancing in three patients. All had bilateral lateral ventricular dilatation with periventricular lucency. On magnetic resonance imaging (n = 3), the cyst was T1 hypointense and T2 isointense in one, hyperintense on both T1 and T2 with a hypointense capsule and nonenhancing on contrast in one (with a giant colloid cyst), and T1 hyperintense and T2 hypointense in one patient. An interhemispheric, transcallosal trajectory combined with transforminal approach (n = 3); combined transforminal and subchoroidal approaches (n = 1); and, interforniceal approach (n = 1) were used., Results: Total excision was performed in four patients. In one patient, a small part of capsule was left attached to thalamostriate vein. Symptoms of raised intracranial pressure showed improvement in all the patients with resolution of hydrocephalus. There was no tumor recurrence at follow-up., Conclusions: Pediatric colloid cysts are rarer than their adult counterparts due to their late detection only after manifestations of raised intracranial pressure, visual or cognitive dysfunction or drop attacks occur. Their radiological appearance varies depending upon the amount of mucoid content, cholesterol, proteins, and water content. The fast development of clinical manifestations in children may be related to rapid enlargement of cyst due to higher water content within them. The transcallosal approach is the "gold standard" of surgery and usually ensures gratifying and lasting results.

Objective: The optimal surgical approach for a trigone meningioma is still controversial. Here, we report two patients with trigone meningioma treated successfully via an occipital inter-hemispheric and trans-cortical approach in the lateral semi-prone position., Clinical Presentation: A 53-year-old woman was admitted to a local hospital with sudden transient dizziness and vomiting. The CT brain scan demonstrated a right intra-ventricular tumour. She was therefore transferred to our hospital for surgical treatment. The other patient was a 67-year-old woman who was admitted to a local hospital after a traffic accident and a CT brain scan revealed an incidental right intra-ventricular tumour. After referral to our hospital, periodic MRI examinations revealed gradual tumour enlargement within a one-year period. Neither of the patients had any neurological deficits, including in the visual fields., Intervention: The head of each patient was positioned so that the tumour-containing right ventricle was oriented downwards and laterally. An occipital inter-hemispheric approach was performed and using a navigation system, the tumour was identified about 1 cm in depth from the cortical surface. After the medial part of the tumour was debulked, the posterior and then the anterior choroidal blood supplies to the tumour were identified. Occlusion of these vessels achieved tumour haemostasis. The tumours were totally removed via a 1.5-cm cortical incision. Brain retraction was minimal because the right hemisphere was pulled down by gravity. Therefore, the para-splenial cisterns were easily accessed, resulting in early release of cerebrospinal fluid. Post-operative MRI showed complete removal of the tumour and the patients had no neurological deficits. Anti-epileptic medication was withdrawn one week after the operation., Conclusions: The occipital inter-hemispheric fissure lacks important bridging veins. The approach used and patient positioning minimized damage to the lateral aspect of the optic radiation and the corpus callosum. Except in patients with very large trigone meningiomas, this approach is useful for decreasing the risk of post-operative hemianopsia or epilepsy, and possibly speech disturbance, even in patients with a tumour in the dominant hemisphere.

Ventricular tumors are excised using both microscope and endoscope as the viewing device. Excision of these tumors requires corticectomy. After these corticectomies, brain has tendency to fall because of CSF drainage. Currently available retractor systems are fixed and thus can be traumatic. On the other hand few systems that require small corticectomy need stereotactic or navigation system aid. These all methods and equipment are costly. Our simple method of using a cylindrical channel retractor custom made out of 20 cc plastic syringe in OT helps in making minimum possible corticectomy. It gives surgeon minimally traumatic, inexpensive, hands free retractor.

Purpose: Intraventricular cavernomas are rare. Even more rare are those presenting in the trigone of the lateral ventricles., Methods: We performed a search of the literature of the last 30 years and identified all cases of intraventricular cavernous angiomas. Trigonal cavernomas were separately identified and analysed. Our search yielded a total of 13 trigonal cavernomas., Results: Of a total of 61 intraventricular cases, 13 were located in the trigone of the lateral ventricles. The most prominent presenting symptom was intracranial hypertension (68.9%), followed by seizures (18.2%) and hemorrhage (13.1%).The literature review revealed a trend of intraventricular cavernomas to present with intracranial hypertension rather than seizures or focal neurologic deficit, unlike their intraparenchymal counterparts. We feel that this difference has received little attention in the international literature. We discuss a possible pathogenetic mechanism for the presence of intracranial hypertension and address different aspects of diagnosis and treatment of this benign lesion., Conclusions: Trigonal cavernomas are benign lesions that have an excellent outcome after radical excision. Symptoms and signs of intracranial hypertension and hydrocephalus may be the prominent initial presentation of this rare ailment.

We document the case of a 69-year-old man presenting with 6 weeks of intractable vomiting. Magnetic Resonance Imaging showed a homogenously enhancing mass in the caudal fourth ventricle. Surgical exploration and biopsy was performed and pathological examination demonstrated a high-grade B-cell lymphoma. The lesion was a primary tumour in an immuno-competent patient. Despite the increasing incidence of primary central nervous system lymphomas this is believed to be only the third ever case to have occurred at this rare site. We suggest that primary B-cell lymphoma should be considered with homogenous lesions of the fourth ventricle.

The following review of the literature describes the ganglioglioma, an uncommon mixed glioneuronal neoplasm, most often of low-grade histology, with a small, albeit well-documented, malignant potential. These tumors exhibit a strong epileptogenic propensity and most often present as new onset seizures or are discovered after a long history of refractory epilepsy. Despite their indolent course, the importance of gross total resection is well recognized to prevent anaplastic and malignant degeneration. Morphologically, the neoplasm is often cystic with an enhancing mural nodule, but can also be entirely solid. They are most often found in the temporal lobe but have been found throughout the neuraxis. An exceedingly rare location of the ganglioglioma is within the lateral ventricle. A systematic literature search revealed only eight reports documenting the occurrence of a ganglioglioma within the lateral ventricle. We describe an illustrative case of an intraventricular ganglioglioma with a prominent cystic component and enhancing mural nodule, which represents the classic radiographic appearance of gangliogliomas described in other locations. A superior parietal lobule approach offered excellent surgical access for tumor removal and the patient has remained free of neurological deficits following surgery. Regardless of location within the central nervous system, ganglioglioma should be on the differential diagnosis for any cystic mass with a mural nodule, particularly in the setting of epilepsy.

Background: Cavernous angiomas are vascular malformations which rarely involve the cavities of the lateral ventricles. Knowledge of the specific clinical and neuroradiological features displayed by these lesions is limited by the scarcity of patients included in the reported series., Objective and Methods: The aim of this study was to compile and analyse the epidemiological, clinical, neuroradiological and surgical characteristics of these lesions as provided by the well-described examples reported in the scientific literature. A total of 49 were gathered, including three patients operated on recently in our Department., Findings and Conclusions: Cavernomas developing within the ventricular cavities attain a larger size than parenchymal counterpart lesions, causing symptoms and signs derived mainly from the mass effect. The characteristic parenchymal hypointense rim is less frequently identified on T2-weighted echo-gradient MRI sequences. Total surgical excision is the treatment of choice for these lesions, yet the surgical routes employed may still be associated with a high rate of neurological complications.

Background: There is increasing interest in the use of neuroendoscopic techniques in neuro-oncology. We report our experience of endoscopic biopsy in patients harbouring intraventricular and paraventricular brain tumours in order to define criteria for the use of this technique., Methods: We identified 23 patients (aged 7-78 years) who underwent endoscopic biopsy for intraventricular or paraventricular lesions considered not suitable for surgical removal and too risky for a stereotactical approach. All of the biopsies were obtained with a flexible endoscope using a free-hand technique., Findings: In 16 patients specimens were adequate and led to a diagnosis; in three patients they were informative but not completely diagnostic; a pathological diagnosis was unavailable in four patients. In 13 patients with a lesion causing an obstruction of the aqueduct, a third ventriculostomy was performed during the same procedure; in one patient with a lesion occluding the Monro foramen, a septostomy was done, while in another case multiple cystostomies were required. No specific complications were observed, either clinically or radiologically, in particular no major bleeding occurred., Conclusions: In our experience, endoscopic biopsy could provide a pathological diagnosis in 19 of 23 patients. Endoscopic biopsy sampling sufficient tissue should be considered as the first choice in selected lesions that are otherwise difficult to approach.

Pilomyxoid astrocytomas have been identified as a variant of pilocytic astrocytoma. They are listed as a novel clinico-pathological entity in the 2007 World Health Organisation (WHO) classification of tumours of the central nervous system. This tumour corresponds to a WHO grade II neoplasm whereas pilocytic astrocytoma corresponds to WHO grade I. We have encountered an infratentorial tumour with pilomyxoid features in an adult. A 25 year old man presented with tinnitus and hyperacusis. Brain MRI revealed a mass occupying the fourth ventricle. We performed partial resection, but no adjuvant therapy was given. The staining index for the anti-Ki-67 monoclonal antibody MIB-1 was less than 1% in this patient. Pilomyxoid astrocytomas are not limited to the hypothalamic/chiasmatic region in children. Additional knowledge and recognition of this entity is necessary to improve treatment of pilomyxoid astrocytoma.

Background: Chordoid glioma is a rare tumour (World Health Organisation grade II) originating from the third ventricle with both glial and chordoid features. It was first described by Brat in 1998. Since there is no detailed information available on the outcome after surgery and adjuvant treatment, we reviewed the literature., Methods: A literature search through PUBMED revealed 50 cases of chordoid glioma. Most reports were found in pathology journals. Information on the postoperative course was sometimes very limited. We reviewed the available literature and studied in detail the presenting symptoms, mortality and postoperative complications in relation to the extent of resective surgery, as well as the importance of adjuvant treatment., Conclusions: Mortality in the immediate postoperative period is 32% and is higher after gross total resection as compared to subtotal resection. Non-fatal postoperative complications are hypothalamic disorders and mental alterations. Gross total resection is the treatment of choice since no recurrence has been reported after macroscopically complete resection, but this is often difficult because of the location and adherence to the hypothalamus. The role of postoperative radiotherapy is uncertain. There is some indication that radiosurgery with or without conventional irradiation is superior to conventional radiation alone. Planned subtotal resection followed by stereotactic radiosurgery can be a safe and effective alternative in a patient in whom gross total resection is considered to be too risky. There is no report on the use of chemotherapy in the treatment of chordoid gliomas. More information about the optimal treatment strategy is needed, and more reports are also needed.

Background: Chordoid glioma, a rare tumour of the third ventricle, represents a distinct clinico-pathologic entity. Thirty nine examples have been described in the literature, mostly in females and in the third ventricle. The clinical presentation is variable but they tend to occur mostly in adults. There is only one report of a chordoid glioma in a 12 year old child., Finding: This paper describes two examples of chordoid glioma in a seven year old female child and a 70 year old male respectively. Radiologically, the paediatric chordoid glioma was located in the juxtaventricular region in the occipital horn of the lateral ventricle and was of mixed density whereas the adult patient had a typical third ventricle location with homogenous contrast enhancement. Gross total surgical removal was achieved in both but the adult patient died post-operatively due to intra ventricular bleeding and bacterial meningitis. The younger patient is doing well at the last follow up two years post-operatively. Microscopically, both showed the classic morphology of chordoid glioma. Ultrastructural examination was suggestive of ependymal differentiation., Conclusion: The younger age and unusual location are some of the rare features which need documentation and have not been described earlier. We propose that chordoid glioma is a variant of an ependymoma (WHO grade II) which arises from tanycytes and should be included in the WHO classification of brain tumors.

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.

Choroid plexus papillomas (CPP) are rare intracranial tumours with a favourable long-term outcome after surgical excision. Although they are histologically benign, local recurrences may occasionally occur, but leptomeningeal dissemination is exceptional. We report an unusual example of a fourth ventricle choroid plexus papilloma with diffuse leptomeningeal seeding. Neither the initial tumour nor the recurrence showed malignant histological features. Treatment with systemic and intrathecal chemotherapy was ineffective in this patient. We review the literature concerning leptomeningeal dissemination of benign choroid plexus papillomas.

Mucus-secreting adenomas or acinar adenoma of the choroid plexus are very rare. We report the case of a 79-year-old male with a 3-year history of occipital headaches with vomiting, ataxia and cerebellar signs. He was first seen due to difficulty while walking. He was admitted to the hospital with significant tumor expansion and clinical deterioration. CT and MRI revealed obstructive hydrocephalus secondary to a large fourth ventricular cyst mass, which enhanced markedly on contrast administration. Pathological findings were consistent with an acinar choroid plexus adenoma. The tumor was attached to the ependymal lining and was strongly adhered to the walls and floor of the IV ventricle. Post-operative bleeding complicated partial removal of this tumor. The patient died 6 h after surgery.