Transcallosal Approach Research Articles

Delayed cyst formation after radiosurgery for arteriovenous malformation: A case report and critical review

Background: Stereotactic radiosurgery (SRS) is a validated treatment option for cerebral arteriovenous malformations (AVMs), even if a greater knowledge of its potential delayed complications is still being acquired. Case Description: A 49-year-old man suffered multiple episodes of cerebral hemorrhage in an approximate 10-year follow-up interval in the context of a left central core AVM with deep venous drainage into the internal cerebral veins (Spetzler Martin Grade 4) despite being treated with gamma knife radiosurgery at two separate timepoints, and with an almost complete obliteration confirmed. Approximately 10 years after the first radiosurgery treatment, he developed severe motor aphasia, Grade 3 right hemiparesis, progressive confusion, and memory deficits. Cerebral imaging revealed cystic degeneration in the AVM’s periphery. Cyst fenestration and cystoperitoneal shunt were attempted. The treatments were temporarily effective, but a progressive cyst enlargement recurred with clinical deterioration. The patient was therefore proposed for surgical mass and cyst excision through an interhemispheric transcallosal approach. The postoperative magnetic resonance imaging showed complete removal of the lesion, and an uneventful post-operative course ensued. At the 6-month follow-up, our patient experienced a noticeable improvement in his speech, power, dexterity and was able to walk autonomously. Conclusion: Cystic degeneration of AVMs is a possible long-term complication after SRS. Long-term follow-up and data on such patients remain crucial, even with evidence of complete nidal obliteration.

A comprehensive approach to lateral ventricular tumor resection: techniques, technologies, and outcomes.

This study reviews lateral ventricular tumors (LVTs), which are rare brain lesions accounting for 0.64-3.5% of brain tumors, and the unique challenges they present due to their location and growth patterns. Once deemed inoperable, advancements in microneurosurgery, imaging, and tumor pathobiology have significantly improved treatment outcomes. This letter summarizes recent studies and key findings in the management of LVTs. Research by S.A. Maryashev et al. identified risk factors for early hemorrhagic complications following the surgical resection of lateral ventricular neoplasms, highlighting the significance of patient characteristics, tumor location, and surgical approach. The study found that factors such as gender, hydrocephalus, tumor blood flow, and Evans index correlate with a higher risk of hemorrhage, with the transcallosal approach having a greater risk compared to the transcortical approach. The utilization of navigation technologies, including fMRI, neuronavigation, and intraoperative brain mapping, has been shown to reduce surgical complications and enhance patient outcomes in the treatment of lateral ventricular meningiomas. Moreover, endoscopic and endoport-assisted endoscopic techniques have proven to be valuable in intraventricular tumor surgery, enabling minimally invasive procedures with better visualization and fewer complications. The integration of advanced surgical techniques, neuroimaging, and neurophysiological monitoring emphasizes the necessity of a multidisciplinary approach to optimize patient outcomes. To improve the study's validity and applicability, further research with larger sample sizes and advanced statistical analyses is needed. This letter advocates for the continued exploration of innovative surgical techniques and technologies to enhance the management of lateral ventricular tumors.

Commentary: Interhemispheric Contralateral Transcallosal Approach to a Giant Thalamic Cavernous Malformation: 2-Dimensional Operative Video.

Commentary: Interhemispheric Contralateral Transcallosal Approach to a Giant Thalamic Cavernous Malformation: 2-Dimensional Operative Video.

Interhemispheric Contralateral Transcallosal Approach to a Giant Thalamic Cavernous Malformation: 2-Dimensional Operative Video.

Thalamic cavernous malformations are challenging lesions to approach given their deep location and proximity to eloquent neurovascular structures. Several approaches to this region exist, and small nuances in the location of the lesion dictate different surgical trajectories. For cavernous malformations presenting to the superomedial surface of the thalamus, the interhemispheric transcallosal approach affords an excellent trajectory as the anterior two-thirds of the superomedial thalamus constitutes the lateral aspect of the floor of the body of the lateral ventricle. In addition, when the cavernous malformation extends laterally, the contralateral adjunct of the interhemispheric transcallosal approach provides optimal visualization of the lateral aspect of the lesion. In this video, we present the case of a 31-year-old woman who presented to our institution with a giant hemorrhagic thalamic cavernous malformation that resulted in rapid neurological decline characterized by ataxia, right hemiparesis, and diplopia. The cavernous malformation was removed using an interhemispheric contralateral transcallosal approach. The patient had near complete resolution of her preoperative deficits with mild residual weakness in her right hand at 3-month follow-up. At 3-year follow-up, magnetic resonance imaging revealed no active cavernous malformation, and the patient had no recurrence of symptoms. This manuscript was conducted in accordance with the ethical standards of our institution's Institutional Review Board. The patient gave informed consent for surgery and video recording.

Transcallosal Retroforniceal Transchoroidal Approach: To the Posterior Third Ventricle and Beyond

The transcallosal retroforniceal transchoroidal approach represents an advanced neurosurgical technique that allows access to lesions located within the posterior third ventricle and mesencephalon. It relies on a comprehensive understanding of microsurgical anatomy and embryology, integrating modern neurosurgical operative techniques to minimize retraction and injury to the normal neuronal structures. We report the cases of 2 patients undergoing treatment via this approach, one presenting with a thalamic cavernoma and the other with cystic low-grade glioma of the midbrain. In these 2 cases, the decision to use the transcallosal approach was mainly due to improved trajectory, gravitational retraction of the hemisphere, and improved delivery of the lesion into the operative field by gravity alone. Through a detailed description of the surgical approach and anatomy, we illustrate the feasibility of the transcallosal retroforniceal transchoroidal approach for accessing lesions located deeply in the brain.

Microsurgical anatomy and approaches to thalamic gliomas. Part 1: A cartography guide for navigating to the thalamus. Integrating 3D model rendering with anatomical dissections.

The selection of appropriate microsurgical approaches to treat thalamic pathologies is currently largely subjective. The objective of this study was to provide a structured cartography map for surgical navigation to treat gliomas involving different surfaces of the thalamus. Fifteen formalin-fixed, silicone-injected cadavers (30 sides) were dissected, and 10 adult brain specimens (20 sides) were used to illustrate thalamic microsurgical anatomy using the Klingler fiber dissection technique. Exposures and trajectories for the six most common microsurgical approaches were depicted using MR data from healthy subjects converted into surface-rendered 3D virtual brain models. Additionally, thalamic surfaces exposed with all six approaches were color mapped on the virtual 3D model and compared side-by-side in 360° views with previously reported microsurgical approaches. These 3D models were then used in conjunction with topographic data to guide cadaveric dissection steps. There are two general surgical routes to thalamic lesions: the subarachnoid transcisternal and transcortical routes. The transcisternal route consists of the following three approaches: 1) anterior interhemispheric transcallosal approach, which exposes the anterior and superior thalamus; 2) posterior interhemispheric transcallosal approach, which exposes the posterosuperior thalamus; and 3) supracerebellar infratentorial approach, which exposes the posteromedial cisternal thalamus and can be extended laterally to approach the posterolateral thalamus by cutting the tentorium. The three transcortical approaches are the 1) superior parietal lobule approach, which exposes the posterosuperior thalamus and is particularly advantageous in the setting of hydrocephalus; 2) transtemporal gyrus approach, which exposes the inferolateral thalamus; and 3) transsylvian transinsular approach, which exposes the lateral thalamus (slightly more superiorly and posteriorly) and is advantageous for pathologies extending laterally into the peduncle, lenticular nucleus, or insula. Microsurgical approaches to thalamic gliomas continue to be challenging. Nonetheless, safe and effective cisternal, ventricular, and cortical corridors can be developed with thoughtful planning, anatomical understanding, and knowledge of the advantages, risks, and limitations of each approach. In some cases, it is wise to combine these approaches with staged procedures, as the authors demonstrate in Part 2. In Part 1 of this two-part series, they discuss thalamic microsurgical anatomy and illustrate the trajectory and exposures of all six approaches to guide decision-making. Part 2 discusses their thalamic glioma microsurgical case series, which utilizes these microsurgical approaches.

Contralateral interhemispheric transcallosal transchoroidal approach to a thalamic glioma: illustrative case.

Thalamic lesions located in the floor of the lateral ventricle pose significant surgical challenges, given their proximity to critical neurovascular structures. Transcortical approaches are often limited by risks of injuring the eloquent cortex and nearby vessels. Furthermore, lesions extending into the third ventricle further impede accessibility. The corticospinal tract (CST), situated close to the thalamus, presents a major obstacle. Diffusion tensor imaging plays a crucial role in overcoming these challenges by accurately delineating the CST's location relative to the lesion, enabling surgeons to plan minimally invasive and safe access. A 32-year-old female presented with progressive right-sided hemiparesis over several days. Magnetic resonance imaging revealed a cystic ring-enhancing thalamic lesion extending into the third ventricle. While supine, the patient underwent surgery via a right pericoronal parasagittal craniotomy followed by a contralateral interhemispheric transcallosal transchoroidal approach. This case exemplifies the utility of the contralateral interhemispheric transcallosal approach for treating thalamic lesions, particularly those extending into the third ventricle. This minimally invasive approach minimizes retraction of the eloquent cortex and reduces the risk of neurovascular injury, potentially leading to improved surgical outcomes and faster recovery.

Suprasellar Immature Teratoma in A 20-year-old Male: A Case Report

Background: Immature teratomas are very rare in adults, especially in the suprasellar area, but they should be considered in the differential diagnosis, particularly when dealing with tumors located in the midline structure. Case presentation: In this study, we present a rare case of an immature teratoma in the suprasellar region of a 20-year-old male. A contrast-enhanced brain MRI revealed a multilocular cystic mass in the suprasellar area, accompanied by non-communicating hydrocephalus. To alleviate intracranial pressure, a shunting procedure was performed to redirect the cerebrospinal fluid. Moreover, tumor resection was carried out using an interhemispheric transcallosal approach. Conclusion: Histopathological examinations unveiled the presence of all three germ layers, followed by immature tissue, consistent with the features of an immature teratoma.

BRAF-mutated suprasellar glioblastoma mimicking craniopharyngioma: illustrative case.

Suprasellar masses commonly include craniopharyngiomas and pituitary adenomas. Suprasellar glioblastoma is exceedingly rare with only a few prior case reports in the literature. Suprasellar glioblastoma can mimic craniopharyngioma or other more common suprasellar etiologies preoperatively. A 65-year-old male with no significant history presented to the emergency department with a subacute decline in mental status. Work-up revealed a large suprasellar mass with extension to the right inferior medial frontal lobe and right lateral ventricle, associated with significant vasogenic edema. The patient underwent an interhemispheric transcallosal approach subtotal resection of the interventricular portion of the mass. Pathological analysis revealed glioblastoma, MGMT partially methylated, with a BRAF V600E mutation. Malignant glioblastomas can mimic benign suprasellar masses and should remain on the differential for a diverse set of brain masses with a broad range of radiological and clinical features. For complex cases accessible from the ventricle where the pituitary complex cannot be confidently preserved via a transsphenoidal approach, an interhemispheric approach is also a practical initial surgical option. In addition to providing diagnostic value, molecular profiling may also reveal therapeutically significant gene alterations such as BRAF mutations.

Microsurgical ventriculostomy of the third ventricle with access through a burrhole in the treatment of midly located deep-seated brain tumors

Currently, endoscopic third ventriculostomy and simultaneous biopsy of deep midline brain tumors are a generally accepted option in neurooncology. Nevertheless, effectiveness of this surgery and diagnostic accuracy of biopsy are not without drawbacks. An alternative to endoscopic surgery may be simultaneous microsurgical third ventriculostomy and biopsy of deep midline tumors. To evaluate effectiveness and safety of burr hole microsurgical third ventriculostomy in the treatment of deep midline brain tumors. We used transcortical (25 cases) and transcallosal (8 cases) approaches for microsurgical third ventriculostomy. Initially scheduled biopsy was performed in 19 cases, partial resection in 6 cases, subtotal resection in 4 cases and total resection in 4 cases. All patients underwent microsurgical third ventriculostomy. In 12 cases, stenting of stoma was performed in addition to ventriculostomy. Biopsy was informative in all cases. Postoperative follow-up period ranged from 3 to 44 months (mean 29 months). There was no postoperative hydrocephalus and need for shunting procedure. Burr hole microsurgery may be an alternative to endoscopic surgery for the treatment of pineal, periaqueductal and third ventricular tumors.

Transcallosal approach and post-operative subdural collections: 12-year paediatric neurosurgery tertiary centre experience.

Following transcallosal surgery for tumour resection, the formation of convexity or interhemispheric subdural cerebrospinal fluid collections may lead to clinical deterioration and may influence decision-making with regards to additional interventions. The aim of this study was to determine the incidence, risk factors, and management of subdural collections following the transcallosal approach in a paediatric cohort. A retrospective case note and radiological review of all children who underwent transcallosal surgery for intraventricular and thalamic tumours was carried out covering a 12-year period (2012-2023) in a single-centre tertiary paediatric neurosurgery unit. Parameters including demographics and clinical information including lesion location, pathology, extent of resection, need for and type of shunt required, as well as depth, laterality, and location of the collection were analysed prior to shunting, and at approximately 3 weeks, 3 months, and latest follow-up available post-operatively in order to further elucidate the natural history of these subdural collections and their clinical significance. Sixty-four cases satisfied the inclusion criteria of transcallosal surgery for tumour resection; 13 did not have adequate post-operative imaging and were excluded. Of the remaining 51 cases, there were 32 children (63%) with post-operative CSF subdural collections, of which 59% were ipsilateral, with the remainder showing bilateral distribution. The overall shunt insertion rate was 25.5% (12 ventriculoperitoneal and 1 subdural-peritoneal shunt) at 3 months, with a mean time to shunting of 19 days post-operatively. Children who developed post-operative subdural collections had a higher rate of shunting, at 37.5%, compared to 5.2% in those who did not. Pre- and post-operative hydrocephalus and subtotal resection were identified as risk factors for development of subdural collections post-operatively. Subdural collections showed a natural course of reduction and regression over follow-up, with the exception of 3 children where they persisted or increased over time; although none of these required shunting. Those children who underwent shunt insertion showed greater regression in the size of the subdural collection over time compared to the non-shunted group. In this paediatric cohort, 25.5 % of children required insertion of a shunt by 3 months following transcallosal surgery. Pre- and post-operative hydrocephalus and subtotal tumour resection were risk factors for development of subdural collections post-operatively.

Case report: Intraventricular tumor removal using transcallosal approach and follow-up in three dogs

This case series describes the surgical removal of lateral ventricular tumors using a transcallosal approach, long-term follow-up, and magnetic resonance imaging (MRI) results of 3 dogs. Two tumors were benign choroid plexus tumors (CPT). One was a grade 2 astrocytoma. Complete tumor removal was achieved using the transcallosal approach. All dogs had ventriculomegaly which remained static or progressed during the follow-up period. All dogs had epileptic seizures before the surgical procedure which persisted despite tumor removal. One dog with CPT was alive after 3 years and 5 months and had minor focal seizures every 3–4 months. No other clinical signs were observed. The second dog with CPT was neurologically free for 17 months after the surgical procedure but died due to acute-onset therapy-resistant generalized epileptic seizures. The third dog with intraventricular astrocytoma experienced epileptic seizures 2 and 4 months after the surgical procedure. The second event was therapy-resistant which led to death.

Lateral ventricle subependymoma resected with a transcallosal approach: illustrative case.

Subependymomas are World Health Organization grade I tumors, and 30% occur in the lateral ventricles. Surgery is the mainstay of treatment, and the transcallosal or transcortical/transsulcal approaches are preferred for those tumors occurring near the foramen of Monro or atrium. Visualization, proximity to the fornix and basal ganglia, hydrocephalus, and brain retraction during surgery make these operations challenging. The authors present the case of a 65-year-old male with a subependymoma located in the left lateral ventricle. The tumor was completely resected using an interhemispheric/transcallosal approach. The authors analyze the anatomopathological features of subependymoma, along with the clinical behavior and therapeutic options. The authors discuss in detail the advantages and disadvantages of the interhemispheric/transcallosal approach for resection of these tumors. Subependymomas are slow-growing lesions with an indolent yet complicated course making surgical removal challenging yet feasible using the correct techniques. The interhemispheric transcallosal approach offers an excellent route for the resection of large subependymomas, but there is still a significant risk for postoperative complications.

Complex arteriovenous malformation of the corpus callosum: Surgical nuances

Introduction: Arteriovenous malformations of the corpus callosum (CC-AVMs) are rare and challenging lesions, accounting for 8–9% of all cerebral AVMs. They are associated with a high risk of recurrent hemorrhage and historically were considered inoperable. This case report describes the successful surgical resection of a high-grade CC-AVM following failed stereotactic radiosurgery. Case Description: A 19-year-old female with an anterior CC-AVM presented with seizures despite being on triple anti-epileptics. The patient had previously undergone conservative management for an intraventricular hemorrhage and stereotactic radiosurgery for the AVM. Pre-operative imaging revealed a 5 cm CC-AVM located at the genu and rostrum of the corpus callosum with intraventricular extension into the third ventricle. The AVM was classified as grade 4 according to the Spetzler-Martin grading system and grade 6 according to the supplementary grading system. The lesion was exposed through the anterior interhemispheric trans-callosal approach, and microsurgical nidal dissection was performed. The large draining vein was identified, coagulated, disconnected, and resected along with the nidus. The total operative time was 12.5 h. Postoperatively, the patient had no neurological deficits and was discharged on day 10. Complete resection was confirmed on postoperative magnetic resonance imaging, and the patient remained seizure-free at the 18-month follow-up visit. Conclusion: This case report demonstrates the feasibility of complete surgical resection for high-grade CC-AVMs that have failed non-surgical therapy. Careful surgical planning and technique can lead to favorable outcomes in these challenging cases.

Anatomical step-by-step dissection of common approaches to the third ventricle for trainees: surgical anatomy of the anterior transcortical and interhemispheric transcallosal approaches, surgical principles, and illustrative pediatric cases.

To create a high-quality, cadaver-based, operatively oriented resource documenting the anterior transcortical and interhemispheric transcallosal approaches as corridors to the third ventricle targeted towards neurosurgical trainees at all levels. Two formalin-fixed, latex-injected specimens were dissected under microscopic magnification and endoscopic-assisted visualization. Dissections of the transcortical and transcallosal craniotomies with transforaminal, transchoroidal, and interforniceal transventricular approaches were performed. The dissections were documented in a stepwise fashion using three-dimensional photographic image acquisition techniques and supplemented with representative cases to highlight pertinent surgical principles. The anterior transcortical and interhemispheric corridors afford excellent access to the anterior two-thirds of the third ventricle with varying risks associated with frontal lobe versus corpus callosum disruption, respectively. The transcortical approach offers a more direct, oblique view of the ipsilateral lateral ventricle, whereas the transcallosal approach readily establishes biventricular access through a paramedian corridor. Once inside the lateral ventricle, intraventricular angled endoscopy further enhances access to the extreme poles of the third ventricle from either open transcranial approach. Subsequent selection of either the transforaminal, transchoroidal, or interforniceal routes can be performed through either craniotomy and is ultimately dependent on individual deep venous anatomy, the epicenter of ventricular pathology, and the concomitant presence of hydrocephalus or embryologic cava. Key steps described include positioning and skin incision; scalp dissection; craniotomy flap elevation; durotomy; transcortical versus interhemispheric dissection with callosotomy; the aforementioned transventricular routes; and their relevant intraventricular landmarks. Approaches to the ventricular system for maximal safe resection of pediatric brain tumors are challenging to master yet represent foundational cranial surgical techniques. We present a comprehensive operatively oriented guide for neurosurgery residents that combines stepwise open and endoscopic cadaveric dissections with representative case studies to optimize familiarity with third ventricle approaches, mastery of relevant microsurgical anatomy, and preparation for operating room participation.

Endoscope-assisted microsurgical resection of a third ventricular immature teratoma.

Reaching a tumor within the third ventricle is challenging, and planning an accessible trajectory is crucial without injuring the surrounding structures. We report a 5-year-old boy presented with headache and a seizure where sequential MRI brain studies in a short time period revealed a rapid growing immature teratoma within the third ventricle with hydrocephalic changes. Several management procedures were performed for CSF diversion and medical treatment of the tumor with chemotherapy and stem cell therapy. The tumor was rapidly growing, and surgical excision was decided. Total resection was achieved via endoscope-assisted microsurgical transcallosal approach. Seven years after surgery, the patient experienced no recurrence of the tumor with a favorable clinical condition. We report a rare case of posterior third ventricular immature teratoma where the endoscope-assisted microsurgical technique was implemented with favorable long-term postoperative outcome.

Outcomes and complications of microscopic transcallosal colloid cyst resection: A single institution experience.

Colloid cysts have always provoked the interest of neurosurgeons due to their benign histology, wide variety of clinical presentations, and differences in reported surgical outcomes. Although recent studies have reported favorable outcomes with different surgical resection approaches, the transcallosal approach remains the most popular approach to date. In this series, we report the clinical and radiological outcomes of the transcallosal approach for the resection of third ventricle colloid cysts in 12 patients. We present a case series of 12 patients who were radiologically diagnosed with a third ventricle colloid cyst who underwent transcallosal resection by a single surgeon in one center over a 6-year period. Clinical, radiological, and surgical data were collected, and surgical outcomes and complications were analyzed. Of the 12 patients diagnosed with colloid cysts, 10 (83%) presented with headache, and five (41%) presented with memory disturbance. All 12 patients showed improvement or resolution of their symptoms following resection. Nine patients (75%) presented with hydrocephalus on radiology. All the patients required preoperative or intraoperative external ventricular drain insertion. Four patients (33%) experienced transient postoperative complications. None of the patients required long-term cerebrospinal fluids shunting. One (8%) of 12 patients experienced transient memory loss. No mortality was recorded during the follow-up. Transcallosal resection of colloid cysts has a favorable prognosis. It allows for complete resection of the cyst with minimal transient postoperative complications. Most patients with postoperative complications show complete resolution of symptoms, with no long-term morbidity.

Cavernous Malformations: What They Have Taught Us.

Cavernous Malformations: What They Have Taught Us.

Anterior Inter-hemispheric Transcallosal Approach for Resection of Colloid Cyst: A Video Abstract

Abstract Background Although histologically benign, colloid cysts have been an entity of interest to neurosurgeons due to the wide array of possible presentations ranging from asymptomatic to high ICP symptoms to sudden death. It is estimated that colloid cysts represent 0.3 to 2% of all brain tumors.1 As they are typically located in the third ventricle, multiple approaches have been adapted and developed for the maximum resection with the least complications given the sensitive anatomy in the area.1 2 The interhemispheric transcallosal approach can be safely performed to fully resect a third ventricle colloid cyst with close to zero recurrence rate and minimal to none permanent deficits.3 This video is an educational illustration of the surgical technique and the related anatomy for the interhemispheric transcallosal approach and how to provide best chances of a benign postoperative course. Case Description In this surgical video, we present a case of a 20-year-old male, a known case of hypertension and un-controlled diabetes type-1, presented to our hospital with on and off headache, dizziness, and diplopia that gradually progressed. His neurological exam was unremarkable including memory function. CT and MRI scans demonstrated a rounded sharply demarcated lesion at the at the roof of the third ventricle, measuring 1 × 1 cm in size. The patient underwent an anterior inter-hemispheric transcallosal approach, with gross total resection of the cyst. In the follow-up office visit, the patient headache has resolved, and he had no seizures with preserved memory functions. Conclusion When removal of the colloid cyst is indicated, the interhemispheric transcallosal approach can be performed safely with gross total resection and minimal neurological deficit. This is a surgical demonstration of the transcallosal approach showcasing the surgical corridors and related anatomy.

Third Ventricular Subependymomas: Clinical Features and Outcomes Over Two Decades

Subependymomas are uncommon, benign slow-growing neoplasms of the central nervous system preferentially arising within the fourth and lateral ventricles. Third ventricle involvement has been described rarely. The aim of this study is to provide the first systematic review of third ventricular subependymomas (TVSE) by analyzing all reported cases over 2 decades and describing a case example. MEDLINE and Embase databases were searched for the 20 years ending January 1, 2022, using relevant MeSH and non-MeSH terms, including "subependymoma" and "third ventricle." Methodology followed PRISMA guidelines. Of 804 identified studies, 131 met inclusion eligibility. The literature yielded 17 patients with TVSE plus our example (18 total). Of these patients, 83% (15/18) presented in adulthood (average age, 42 ± 19 years), of whom 73% were women. The pediatric cohort age was 5 ± 1 years, 67% (4/6) of whom were girls. The most common presenting symptom in both cohorts was headache (80%), followed by memory disturbances and vomitus. In adults, symptomatic tumors were approached by open craniotomy in all but 1 case, most using a transcallosal approach. Gross total resection was obtained in 73%. A ventriculoperitoneal shunt was inserted in 2/15 adult and 4/6 pediatric patients. Overall, both cohorts showed symptomatic improvement without disease recurrence. One patient died perioperatively. Subependymomas should be considered in the differential diagnosis of third ventricular tumors. The clinical presentation of TVSE mainly parallels hydrocephalus symptoms and, hence, awareness is of vital importance for timely treatment. The surgical goal should be gross total resection, which can be curative and offers greatest clinical improvement across the population.