Tectal Glioma Research Articles

PATH-11. TECTAL GLIOMA: CLINICAL, PATHOLOGICAL, AND MOLECULAR FEATURES

Abstract Tectal glioma (TG) is a rare lower-grade glioma (LrGG) that occurs in the tectum, mainly affecting children. The clinical course is usually indolent, with common symptoms including headache, gait disturbance, and ataxia resulting from obstructive hydrocephalus. TG shares pathological similarities with pilocytic astrocytoma (PA), but recent genetic analyses have revealed distinct features, such as alterations in KRAS and BRAF. Here, we report the clinical, radiological, pathological, and molecular characteristics of TG cases in our hospital. We conducted a retrospective review of cases clinically diagnosed as TG and surgically treated at our institute between January 2005 and March 2023. Molecular analysis, including genome-wide DNA methylation profiling, was performed. Six cases were identified and the median age at diagnosis was 30.5 years (range: 6–45 years). The mean tumor diameter was 22.8 mm (range: 14.7–33.2 mm), with obstructive hydrocephalus observed in all cases. Contrast enhancement of the tumor was noted in four cases and cyst formation occurred in two cases. Four patients underwent biopsy or biopsy with endoscopic third ventriculostomy, and two patients underwent tumor resection. Postoperatively, three patients received radiotherapy and two were treated with chemotherapy. The median overall survival was 6.2 years (range: 1.4–7.3 years), and the median progression-free survival was 3.4 years (range: 1.4–7.3 years). Histological diagnoses included three cases of PA, one case of astrocytoma, and two cases of high-grade glioma. Among the three patients who underwent molecular evaluation, including genome-wide methylation analysis, two had KRAS mutation and one had H3-3A K27M mutation. Our results demonstrate the diverse histological and molecular characteristics of TG distinct from other LrGGs. Given the heterogeneous pathological background and the risk of pathological progression in TG, we emphasize the importance of comprehensive diagnosis, including molecular evaluation.

RADT-48. ANALYSIS OF PROTON RADIATION THERAPY INDUCED CONTRAST ENHANCEMENT: A SINGLE INSTITUTION, RETROSPECTIVE STUDY

Abstract Proton radiotherapy (PRT) has superior physical dose distribution with a lesser integral off target radiation dose exposure compared with standard photon radiotherapy resulting in reduced toxicity of uninvolved normal tissues. However, there may be toxicity in areas targeted for high dose treatment as a result of uncertainty about the relative radiobiologic effect (RBE) of proton radiotherapy compared with photon radiotherapy and the potential for localized high doses at the end of the proton beam range (Bragg peak). This may result in radiation-induced contrast enhancement (RICE) reflecting transient toxicity or permanent injury, particularly when associated with concurrent chemotherapy. We analyzed 150 consecutive adult patients, with a histopathologic diagnosis of CNS malignancy, who underwent only PRT at Johns Hopkins Hospital between 2019 – 2023 with least 1 year of follow-up imaging. RICE was defined as a new post-treatment contrast enhancement on MRI within the radiation field. The determination of disease progression or RICE was confirmed with additional follow-up MRI or pathology. RICE was identified in 14 cases (9.3%). The median age was 48 y (range 19 – 72 years), sex 50% female. Diagnosis was 5 astrocytoma, 3 meningioma, 2 glioblastoma, 1 medulloblastoma, 2 oligodendroglioma, 1 tectal glioma. 4/5 astrocytoma patients were grade 2, 2/3 meningioma was grade 1, 1/3 was grade 2, 2/2 oligodendroglioma was grade 2. The median time since completing PRT to development of RICE was 3.5 months. The median radiation dose was 52.20 Gye (range 23.40 - 60.06). Dexamethasone was used in 11 patients (78 %) and in bevacizumab was used 2. Chemotherapy with temozolomide 7 (50%), PCV 1, and none in 5. 12 (85%) patients were still alive. PRT can also be associated with radiation injury in the target, and more information is needed about the incidence, natural history, and associations with localized dosimetry.

Tectal glioma: clinical, radiological, and pathological features, and the importance of molecular analysis.

Tectal glioma (TG) is a rare lower grade glioma (LrGG) that occurs in the tectum, mainly affecting children. TG shares pathological similarities with pilocytic astrocytoma (PA), but recent genetic analyses have revealed distinct features, such as alterations in KRAS and BRAF. We conducted a retrospective review of cases clinically diagnosed as TG and treated at our institute between January 2005 and March 2023. Six cases were identified and the median age was 30.5years. Four patients underwent biopsy and two patients underwent tumor resection. Histological diagnoses included three cases of PA, one case of astrocytoma, and two cases of high-grade glioma. The integrated diagnosis, according to the fifth edition of the World Health Organization Classification of Tumours of the central nervous system, included two cases of PA and one case each of diffuse high-grade glioma; diffuse midline glioma H3 K27-altered; glioblastoma; and circumscribed astrocytic glioma. Among the three patients who underwent molecular evaluation, two had KRAS mutation and one had H3-3A K27M mutation. Our results demonstrate the diverse histological and molecular characteristics of TG distinct from other LrGGs. Given the heterogeneous pathological background and the risk of pathological progression in TG, we emphasize the importance of comprehensive diagnosis, including molecular evaluation.

PDOC-12 PEDIATRIC BRAIN TUMOR INCIDENCE, AND TREATMENT MODALITY AT KILIMANJARO CHRISTIAN MEDICAL CENTER

Abstract INTRODUCTION Pediatric brain tumors (PBT) a significant health concern, they are the primary cause of cancer-related deaths among children. PBTs in Low- and Middle-Income Countries are diagnosed late due to insufficient resources. This abstract describes Pediatric Brain tumor incidence and treatment modalities at Kilimanjaro Christian Medical Center (KCMC) Cancer Care Center (CCC), Moshi, Tanzania from December 2016 to March 2024. METHOD Data on pediatric patients treated at the CCC between Dec. 2016 and March 2024, were analyzed. Inclusion criteria were a primary brain tumor and patients aged 0-19 at the time of diagnosis. All patients were previously diagnosed by computer tomography/ magnetic resonance imaging. Variables retrospectively collected from patient’s medical records were: demographic characteristics (age, gender, Place of residence, and insurance status), previous history of malignant diseases, incidence date, and treatment modality. RESULTS Total of 748 cases of pedeatric cancer were diagnosed at CCC. Of all the pediatric cancers diagnosed, brain cancer accounted for 22(2.9%). Out of these cases of brain cancer, 63.6% were males and 36.4% were females.Majority of them came within the Kilimanjaro region. 41% were palliated while 59% had a curative intent at the time of diagnosis, 22.7% died between December 2016 to March 2024.Embryonal tumors were (40.9%) with a breakdown that includes 6 Medulloblastoma and 3 cases of Craniopharyngioma (teratoid/rhabdoid), gliomas (36.4%) with sub-types such as Ependymoma, Anaplastic Astrocytoma, Pilocytic Astrocytoma, Pineocytoma, Stem glioma, and Tectal glioma, unspecified cases (13.6%), and Pineoblastoma were (9.1%). Surgery was used in 40.9% of cases, radiotherapy in 31.8%, and chemotherapy in 72.7%. Chemoradiotherapy was used in 31.8% of cases. 13.6% of cases utilized a combined approach, including chemotherapy, radiotherapy, and surgery. CONCLUSION PBT incidence at KCMC is 2.9%, improving access to screening, accurate diagnosis and treatment modalities are essential in identifying and managing PBT in our setting.

LGG-43. LASER-ASSISTED ENDOSCOPIC RESECTION OF TECTAL GLIOMA IN A 3-YEAR-OLD CHILD

Abstract BACKGROUND Pediatric tectal gliomas generally have a benign clinical course. However, some patients may present with non-communicating hydrocephalus needing endoscopic procedures. Historically, lasers have been used in neurosurgical procedures including neuroendoscopy, but their adoption was limited by a significant rate of complication due to their inappropriate wavelength and uncontrollable tissue interaction. Recently, a 2-micron near-infrared laser with adequate wavelength and minimal tissue penetration became available. CASE-REPORT We describe the case of a 3-year-old child who presented with gait ataxia, papilloedema and headache. Magnetic Resonance (MR) was performed and he was diagnosed with obstructive hydrocephalus due to tectal glioma. Endoscopic third ventriculostomy (ETV) and simultaneous endoscopic biopsy were performed during the same surgery using a single burr hole with a rigid endoscope, a 2-micron continuous-wave thulium laser and the aid of neuronavigation. After tumoral sample removal, the laser was used for hemostasis and to evaporate tissue near the tumour without mechanical stress to the brain tissue. The final histological analysis identified a non-otherwise specified (NOS) low-grade glioma. The hospitalization was uneventful and the boy was discharged home after 4 days. No new cognitive impairment was reported secondary to this procedure and the symptoms present in the preoperative period completely improved. At 1-year follow-up, neurological examination findings were unremarkable, and there was no radiographic evidence of tumour progression. CONCLUSIONS The use of the neuroendoscopic laser permits cutting and coagulating simultaneously, avoiding multiple instruments’ use (forceps and coagulation). It therefore makes neuroendoscopic procedures more straightforward with a minimum need to change tools, and particularly suitable also in a pediatric setting.

Diagnosis and Treatment of Sylvian Aqueduct Syndrome.

Sylvian aqueduct syndrome is a rare complication after ventriculoperitoneal (V-P) shunt surgery and is not easily diagnosed. A 26-year-old male with obstructive hydrocephalus due to tectal glioma was treated with a V-P shunt surgery in another hospital. After the surgery, the patient developed an intractable disturbance of consciousness. When the V-P shunt pressure was raised or lowered, the patient's consciousness disorder still could not be improved. The patient was diagnosed with Sylvian aqueduct syndrome, a rare complication after V-P shunt operation. The paper clarifies the treatment experience with simultaneous endoscopic third ventriculostomy (ETV) and tectum gliomas biopsy, postoperative pathology suggestive of fibrillary astrocytoma; after surgery, the Sylvian aqueduct syndrome was cured and the patient recovered well. The preferred treatment for obstructive hydrocephalus caused by tumors in the Pineal region is the ETV operation. If an ETV operation and biopsy operation are performed simultaneously, more details need to be noted.

Surgical management of Rathke cleft cysts in pediatric patients: a single institution experience

ObjectiveRathke cleft cysts (RCCs) are benign, epithelial-lined sellar lesions that arise from remnants of the craniopharyngeal duct. Due to their rarity in the pediatric population, data are limited regarding the natural history and optimal management of growing or symptomatic RCCs. We present our institutional experience with the surgical management of RCCs.MethodsWe performed a retrospective study of consecutive RCC patients ≤ 18 years old treated surgically at our institution between 2006 and 2022.ResultsOverall, 567 patients with a diagnosis of pituitary mass or cyst were identified. Of these, 31 had a histopathological diagnosis of RCC, 58% female and 42% male. The mean age was 13.2 ± 4.2 years. Presenting symptoms included headache (58%), visual changes (32%), and endocrinopathies or growth delay (26%); 13% were identified incidentally and subsequently demonstrated growth on serial imaging. Six percent presented with symptomatic intralesional hemorrhage. Surgical approach was transsphenoidal for 90% of patients and orbitozygomatic for 10%. Preoperative headaches resolved in 61% of patients and preoperative visual deficits improvement in 55% after surgery. New pituitary axis deficits were seen in 9.7% of patients. Only two complications occurred from a first-time surgery: one cerebrospinal fluid leak requiring lumbar drain placement, and one case of epistaxis requiring cauterization. No patients experienced new visual or neurological deficits. Patients were followed postoperatively with serial imaging at a mean follow-up was 62.9 ± 58.4 months. Recurrence requiring reoperation occurred in 32% of patients. Five-year progression-free survival was 47.9%. Except for one patient with multiple neurological deficits from a concurrent tectal glioma, all patients had a modified Rankin Scale score of 0 or 1 (good outcome) at last follow-up.ConclusionDue to their secretory epithelium, pediatric RCCs may demonstrate rapid growth and can cause symptoms due to local mass effect. Surgical management of symptomatic or growing pediatric RCCs via cyst fenestration or partial resection of the cyst wall can be performed safely, with good neurologic outcomes. There is a nontrivial risk of endocrinologic injury, and long-term follow up is needed due to high recurrence rates.

Modern Radiation Treatment Planning Parameters and Outcomes in Pediatric Tectal Gliomas

Purpose/Objective(s)Pediatric low-grade tectal gliomas are rare, indolent tumors of the brainstem. We reviewed outcomes of pediatric patients diagnosed with low-grade tectal gliomas and report dosimetric parameters for those receiving radiotherapy (RT). Material/MethodsWe retrospectively reviewed all pediatric patients (age <18) at our institution diagnosed with a low-grade glioma between 1993 and 2020 (n=288). Twenty-three patients with tectal gliomas were identified. Patients who received RT (n=8) had detailed dosimetric analyses performed. Doses to critical structures and any resulting toxicities were reviewed. Minimum follow-up was 2 years and complete follow-up was available for all patients. ResultsTwenty-three patients, with a median age of 8.9 years, were included (range 0.5 – 16.2 years). At a median follow-up of 7.4 years (range: 2 – 24 yrs), all were alive at the end of the study period. Three patients (13%) were treated with upfront RT; none of these patients developed local failure (LF) after a median follow-up of 10.6 years. One patient was treated with upfront chemotherapy with no evidence of progression afterwards. Nineteen patients were initially observed after diagnosis and 26% of them (n=5) experienced local progression. All 5 were treated with salvage RT, with one patient requiring further treatment with chemotherapy. Fractionation schedules for patients undergoing upfront or salvage RT included 50.4 Gy in 28 fractions (n = 4), 54 Gy in 30 fractions (n=2), and 51 Gy in 30 fractions (n=2). For patients treated after 2007, the gross tumor volume (GTV) was delineated on a T2 MRI with an average GTV-to-PTV expansion of 4.5 mm (range: 3-5 mm). Detailed dosimetric parameters were available for all patients treated with RT. ConclusionOur review supports the indolent behavior for most tectal gliomas. For the subset of tumors with evidence of progression, modern photon RT results in excellent oncologic outcomes with minimal late effects.

The Role of Advanced MRI Sequences in the Diagnosis and Follow-Up of Adult Brainstem Gliomas: A Neuroradiological Review.

The 2021 WHO (World Health Organization) classification of brain tumors incorporated the rapid advances in the molecular, genetic, and pathogenesis understanding of brain tumor pathogenesis, behavior, and treatment response. It revolutionized brain tumor classification by placing great emphasis on molecular types and completely splitting adult-type and pediatric-type diffuse gliomas. Brainstem gliomas (BSGs) are the leading primary tumors of the brainstem, although they are quite uncommon in adults compared with the pediatric population, representing less than 2% of adult gliomas. Surgery is not always the treatment of choice since resection is rarely feasible and does not improve overall survival, and biopsies are not generally performed since the location is treacherous. Therefore, MRI (Magnetic Resonance Imaging) without and with gadolinium administration represents the optimal noninvasive radiological technique to suggest brainstem gliomas diagnosis, plan a multidisciplinary treatment and for follow-up evaluations. The MRI protocol encompasses morphological sequences as well as functional and advanced sequences, such as DWI/ADC (Diffusion-Weighted Imaging/Apparent Diffusion Coefficient), DTI (Diffusion Tensor Imaging), PWI (Perfusion-Weighted Imaging), and MRS (Magnetic Resonance Spectroscopy), which improve the accuracy of the diagnosis of BSGs by adding substantial information regarding the cellularity, the infiltrative behavior toward the v fiber tracts, the vascularity, and the molecular changes. Brainstem gliomas have been divided into four categories on the basis of their MRI radiological appearance, including diffuse intrinsic low-grade gliomas, enhancing malignant gliomas, localized tectal gliomas, and other forms. The aim of our review is to provide insight into the role of advanced MRI sequences in the diagnosis and follow-up of adult brainstem gliomas.

Brainstem glioma clinical features and treatment outcomes: a case series

A diverse category of gliomas that mostly affect youngsters are known as brainstem gliomas (BGs). The diffuse intrinsic pontine glioma (DIPG), exophytic medullary glioma, and tectal glioma can be divided into categories based on architecture and clinical behaviour. The most frequent BG is DIPG. The median age at start is 6.5 years, and the median survival is less than a year. The fact that adults with DIPG live longer suggests that their tumours are less aggressive and have physiologically distinct origins than those in children. Patients may appear with one or more of the following symptoms: ataxia, long tract signs, or malfunction of the cranial nerves. The majority of the pons is occupied by an infiltrative lesion on magnetic resonance imaging, and contrast enhancement is typically not noticeable. Fractionated radiation is the norm in medicine.

Predicting disease progression and the need for tumor-directed treatment in tectal plate gliomas.

Tectal plate gliomas are rare, slow-growing tumors of the midbrain that are discovered predominantly in the pediatric population. Because of their indolent nature, treatment mainly consists of observation and management of hydrocephalus. Unfortunately, a subset of tectal gliomas may exhibit tumor enlargement and disease progression. Currently, there are no established guidelines for predicting future progression of tectal gliomas or the need for tumor-directed treatment. In this paper, the authors present a large case series of tectal plate gliomas with the aim of determining early indicators of tumor progression and the need for tumor-directed treatment in a pediatric population, along with providing their experience in treating progressive tumors. A retrospective chart review of 170 patients diagnosed with tectal plate glioma from a single institution, of whom 67 were pediatric patients (≤ 18 years of age), was performed. Univariate analysis was used to determine statistically significant predictors of symptomatic disease progression requiring eventual tumor-directed therapy. The median patient age of the full cohort was 24 years (range 0-73 years). Compared with the pediatric population, the adult population had more instances of incidental lesions (p < 0.001) and lower rates of hydrocephalus (50% vs 84%, p < 0.001). Of the pediatric patients who had ≥ 5 years of follow-up (n = 51), 12 (24%) experienced radiological progression and 13 (25%) required treatment for their tumor. The 1-year, 5-year, and 10-year radiographic progression-free survival (PFS) rates were 98%, 90%, and 86%, respectively. In univariate analysis, lesion involvement of the pons, moderate T1 hypointensity, and moderate contrast enhancement on baseline radiology were significantly associated with worse radiographic PFS. Alternatively, significant predictors of requiring tumor-directed treatment included extraocular eye movement abnormalities at presentation, involvement of the lesion beyond the tectum on baseline radiology, moderate T1 hypointensity, moderate contrast enhancement, and an increase in total lesion size during progression. At the most recent follow-up, 94% of the patients had stable/nonprogressive disease, 2% had progressive disease, and 4% died of tumor progression. Patients who demonstrate radiographic progression may not necessarily experience clinical/symptomatic progression or require tumor-directed treatment. Certain patient presentation characteristics and baseline radiographic features may be predictive of worse radiographic PFS or the need for future tumor-directed treatment in the pediatric population. Typically, the natural history of these lesions lends to excellent long-term survival, even in patients who experience clinical progression, should appropriate treatment be initiated.

342 Predicting Early Disease Progression in Tectal Plate Gliomas

INTRODUCTION: Tectal gliomas are slow-growing tumors of the midbrain. Due to their indolent nature, treatment mainly consists of observation and management of hydrocephalus. However, a subset of tectal gliomas may exhibit tumor enlargement and disease progression. Currently, there are no established guidelines for predicting future progression of tectal gliomas. Further, given the rarity of these tumors, studies in the literature are limited to &lt;50 patients. METHODS: We performed a retrospective chart review of 172 patients diagnosed with tectal glioma. In addition to descriptive statistics, we performed univariate analysis using Student’s t-test and Chi-squared testing to determine if significant differences exist between patients with tumor progression versus those without progression. RESULTS: The median patient age was 24 years (range: 0-73 years); of these, 69 were pediatric (≤18 years). Hydrocephalus was present in 64% of cases. Lesions were incidentally detected in 37% of the cohort and were only present in the adult population. Of the patients that had &gt; 1 year follow-up (n = 145), 26 experienced radiological progression (18%) with 19 requiring tumor-directed treatment (13%). Predictors of progression included younger age at diagnosis (p = 0.005), expansion of the lesion beyond the tectum on initial imaging (p &lt; 0.001), moderate T1 signal (p &lt; 0.001), and mild or moderate contrast enhancement (p = 0.011 and p &lt; 0.001, respectively). At most recent follow-up, 92% had stable disease, 3% had progressive disease, 1% died from tumor progression, and 3% died of other causes. CONCLUSIONS: Certain characteristics of radiographic imaging may be predictive of future disease progression. In patients with progression, excellent survival can be achieved if progression is detected early and appropriate treatment is initiated.

347 Management of Rathke Cleft Cysts in Children: The Rady Children’s Hospital Approach

INTRODUCTION: Rathke cleft cysts (RCCs) are benign, epithelial-lined sellar lesions that arise from remnants of the craniopharyngeal duct. Due to their rarity in the pediatric population, data are limited regarding the natural history and management of growing or symptomatic RCCs. METHODS: We performed a retrospective study of RCC patients age ≤18 years treated between 2006-2022 at our institution. RESULTS: 567 patients with a diagnosis of pituitary mass or cyst were identified. Of these, 31 underwent surgery and had a histopathological diagnosis of RCC, 58% female and 42% male. Mean age was 13.2 +/- 4.2 years. Presenting symptoms included headache (58%), visual changes (35%), and endocrinopathies or growth delay (26%); 13% were identified incidentally and grew significantly on serial imaging. Six percent presented with intralesional hemorrhage. Surgical approach was transsphenoidal for 90% of patients and orbitozygomatic for 10%. Preoperative headaches resolved in 61% of patients after surgery. New pituitary axis deficits were seen in 9.7%. Only two complications occurred from a first-time surgery: one cerebrospinal fluid leak requiring lumbar drain placement, and one case of epistaxis requiring cauterization. No patients experienced new visual or neurological deficits. Patients were followed postoperatively with serial imaging. Mean follow-up was 62.9 +/- 58.4 months. Recurrence requiring reoperation occurred in 32% of patients (transsphenoidal n = 8, pterional n = 2). Five-year progression-free survival was 47.9%. Except for one patient with multiple neurological deficits from a concurrent tectal glioma, all patients had a modified Rankin Scale score of 0 or 1 (good outcome) at last follow-up. CONCLUSIONS: Due to their secretory epithelium, RCCs may demonstrate rapid growth and recurrence. Incidental RCCs can be managed conservatively, whereas symptomatic or growing lesions may be fenestrated or resected. Due to their dynamic and variable nature, careful patient selection and close postoperative surveillance are critical to optimizing patient outcomes.

A Supracerebellar Infratentorial Intercollicular Approach for a Tectal Glioma in a 15-year-old Girl with NF-1. A Case Presentation and Discussion

A Supracerebellar Infratentorial Intercollicular Approach for a Tectal Glioma in a 15-year-old Girl with NF-1. A Case Presentation and Discussion

Retrospective Analysis of Imaging Characteristics of Tectal Gliomas.

Tectal gliomas (TGs) are rare tumors that involve critical locations in the brainstem, including the superior and inferior colliculi and the Sylvian aqueduct. The rarity of these tumors and the lack of large clinical studies have hindered adequate understanding of this disease. We sought to determine the association between imaging characteristics of TG and progression-free survival (PFS). In this retrospective cohort study, impact of imaging characteristics (contrast enhancement, calcifications, cystic changes, presence of hydrocephalus) on survival was analyzed for 39 patients with TG. We used the Kaplan-Meier survival analysis method for determining the association between imaging characteristics and PFS. Progression-free survival was measured from time of diagnosis to radiographic or pathological disease progression during observation period. Progression was defined as more than 25% increase of the lesion in size, per response assessment in neuro-oncology, together with clinical deterioration and/or a need for intervention. Progression-free survival differences by various imaging characteristics were assessed using the log-rank test and univariable Cox proportional hazard regression. Because most of the studies in the current literature tend to overrepresent pediatric patients, we aimed to determine the association between TG tumors' imaging characteristics and PFS in both adult and pediatric patients. All statistical analyses were performed using STATA version 16.1 (Stata Corp, College Station, Tex). Of the 39 patients, radiographic tumor progression was observed in 15 cases (38.5%). Median PFS for 39 patients during observation was 21.8 years. Tectal gliomas that showed contrast enhancement initially or developed contrast enhancement during surveillance on magnetic resonance imaging had significantly lower PFS than those without (hazard ratio, 3.55; 95% confidence interval, 1.09-11.58; log-rank P value, 0.02). Analysis of this patient population showed that contrast-enhancing TGs should not be categorically defined as benign lesions. This subgroup of patients should be followed closely for signs of progression.

Atypical Molecular Features of Pediatric Tectal Glioma: A Single Institutional Series.

We present 4 children (diagnosed between 1 and 8y, 3 females and 1 male) with molecularly distinct tectal gliomas (2 KRAS mutant, 1 EGFR mutant, 1 SRGAP3-RAF-1 fusion) that contributes to the growing literature of this uncommonly biopsied tumor. The patient with EGFR R222C mutation had a more severe course, earlier diagnosis, subsequent leptomeningeal metastatic disease, required more aggressive therapies, and died 9 years after diagnosis. Patients with KRAS mutations and SRGAP3-RAF-1 fusion had a more indolent course. Our series expands the molecular phenotype of tectal glioma with the potential for leptomeningeal dissemination. Future studies on establishing genotypic/phenotypic correlation from those who undergo biopsy are needed.

Tectal Plate Gliomas Masquerading as Idiopathic Aqueduct Stenosis

Aqueduct stenosis is a recognized cause of obstructive hydrocephalus in children and can be treated effectively with endoscopic third ventriculostomy. Preoperative magnetic resonance imaging is often diagnostic of the cause of aqueduct stenosis. We describe 2 pediatric cases with obstructive hydrocephalus secondary to a working diagnosis of idiopathic aqueduct stenosis. Following successful endoscopic third ventriculostomy, repeat magnetic resonance brain imaging revealed tectal plate glioma as the primary cause of obstruction. We believe these 2 reported cases demonstrate a previously unreported phenomenon whereby concealed tectal gliomas presenting with hydrocephalus are only unmasked following relief of hydrocephalus and decompression and normalization of the ventricular system. We aim to raise awareness about this unusual phenomenon and recommend routine postoperative interval imaging following endoscopic third ventriculostomy to avoid missing underlying pathology masquerading as aqueduct stenosis.

An audit of endoscopic third ventriculostomy (ETV) in a regional paediatric neurosurgical centre assessing the accuracy and feasibility of the ETV success score.

Endoscopic third ventriculostomy success score (ETVss) is widely utilised to predict outcomes for ETV. Accurate prediction of success for a procedure is of vital importance both for selecting the optimal management plan and for obtaining informed consent. Existing literature demonstrates a variety of opinions on the accuracy of the currently utilised ETVss and recommends a range of techniques to reduce the number of subsequent ventriculo-peritoneal (VP)-shunt insertions, prompting the present study. We retrospectively analysed data for ETV cases since 2007 to review success rate in our regional paediatric neurosurgical centre and if the currently utilised ETVss successfully predicted outcomes. Failed ETV cases were defined as any patient who received a VP-shunt at any time following ETV. Data was analysed with MS ExcelR and RStudioR. 44 ETVs were performed over 13years with approximately equal distribution between male and female patients; median age 7years (IQR 4-13years). Overall, mean ETVss for these 44 procedures was 78%; actual success rate was 70% with no statistically significant difference between them (p = 0.286; Welch two sample t-test). Accuracy of ETVss varied with pathology: tectal gliomas (mean ETVss 75% and actual success 78%); cerebellar tumours (mean ETVss 85% and actual success 81%); other tumours (mean ETVss 75% and actual success 81%); aqueduct stenosis (mean ETVss 71% and actual success 69%); and other pathologies (mean ETVss 70% and actual success 60%). < 1month and 1-6months and 1-10years and > 10years contributed equally to the accuracy of ETVss. Non-telencephalon tumours and obstruction at the level of the mid-brain are most strongly associated with successful ETV outcome. These findings can be used to modify the currently utilised ETVss to further improve accuracy of outcome prediction. We recommend a modified-ETVss (m-ETVss) and a future larger adequately powered prospective study to validate this.

Management strategies for pediatric patients with tectal gliomas: a systematic review.

Pediatric tectal gliomas generally have a benign clinical course with the majority of these observed radiologically. However, patients often need treatment for obstructive hydrocephalus and occasionally require cytotoxic therapy. Given the lack of level I data, there is a need to further characterize management strategies for these rare tumors. We have therefore performed the first systematic review comparing various management strategies. The literature was systematically searched from January 1, 2000, to July 30, 2020, to identify studies reporting treatment strategies for pediatric tectal gliomas. The systematic review included 355 patients from 14 studies. Abnormal ocular findings-including gaze palsies, papilledema, diplopia, and visual field changes-were a common presentation with between 13.6 and 88.9% of patients experiencing such findings. CSF diversion was the most performed procedure, occurring in 317 patients (89.3%). In individual studies, use of CSF diversion ranged from 73.1 to 100.0%. For management options, 232 patients were radiologically monitored (65.4%), 69 received resection (19.4%), 30 received radiotherapy (8.4%), and 19 received chemotherapy (5.4%). When examining frequencies within individual studies, chemotherapy ranged from 2.5 to 29.6% and radiotherapy ranged from 2.5 to 28.6%. Resection was the most variable treatment option between individual studies, ranging from 2.3 to 100.0%. Most tectal gliomas in the pediatric population can be observed through radiographic surveillance and CSF diversion. Other forms of management (i.e., chemotherapy and radiotherapy) are warranted for more aggressive tumors demonstrating radiological progression. Surgical resection should be reserved for large tumors and/or those that are refractory to other treatment modalities.

Surgical techniques in the management of supratentorial pediatric brain tumors: 10 years' experience at a tertiary care center in the Middle East.

Background: The goal of this retrospective study is to present the first epidemiological data on pediatric supratentorial central nervous system (CNS) tumors in Lebanon and to review the various surgical management strategies used.Methods: We conducted a retrospective case series of all pediatric patients who presented with a supratentorial CNS tumor and underwent surgery at our institution between 2006 and 2016. We collected and analyzed demographic characteristics, tumor location, clinical manifestations, histopathology, and surgical management strategies and outcome, and discussed them after dividing the tumors as per location and in view of published literature.Results: Ninety-nine children were studied with a male-to-female ratio of 2.3:1 and a mean age of 8.5 years. The most common location was convexity (44%) and included low-grade and high-grade glial tumors, along with other miscellaneous lesions. The next location was sellar/diencephalic (34%), including craniopharyngiomas, hypothalamic/optic pathway/thalamic gliomas, hamartomas, and pituitary/Rathke’s cyst, where there was notable use of endoscopic techniques (21%). Tumors in the pineal region (13%) were tectal gliomas, germ cell tumors, and pineoblastomas and were mostly treated endoscopically. The last group was lateral intraventricular tumors (8%) and was mostly choroid plexus lesions and ependymomas. Overall, the surgical objective was achieved in 95% with mild/moderate complications in 17%.Conclusion: A variety of pathologies may affect the pediatric population in the supratentorial region. Different surgical strategies, including microsurgical and endoscopic techniques, may be employed to remove, debulk, or biopsy these tumors depending on their location, suspected diagnosis, prognosis, and the need for treatment of possible associated hydrocephalus.