Pediatric cerebellar astrocytoma: a review

Pediatric hemispheric cerebellar low-grade gliomas: clinical approach, diagnosis, and management challenges-experience at a tertiary care children's hospital

PURPOSE

This study aims to provide an exhaustive analysis of pediatric low-grade gliomas (pLGGs) in the cerebellar hemispheres, focusing on incidence, clinical characteristics, surgical outcomes, and prognosis. It seeks to enhance understanding and management of pLGGs in the pediatric population.

METHODS

We conducted an observational, descriptive, retrospective, and cross-sectional study at a pediatric hospital, reviewing medical records of 30 patients with cerebellar hemispheric pLGGs treated from December 2014 to January 2023. Data collection included demographics, clinical presentation, imaging findings, surgical approach, postoperative complications, histopathological diagnosis, hydrocephalus management, and follow-up. Molecular markers and adjuvant therapies were also analyzed.

RESULTS

The cohort predominantly presented with cerebellar symptoms, with 60% showing hydrocephalus at diagnosis. MRI with gadolinium was crucial for diagnosis. Surgical focus was on achieving gross total resection (GTR), accomplished in 70% of cases. Postsurgical hydrocephalus was less common, and cerebellar mutism was not reported. While a complete molecular analysis was not performed in all cases, available data suggest significant influence of molecular markers on prognosis and therapeutic options of pLGGs.

CONCLUSIONS

This study highlights the unique clinical and molecular characteristics of cerebellar hemispheric pLGGs in children. The lower incidence of postoperative hydrocephalus and absence of cerebellar mutism are notable findings. Emphasizing a multidisciplinary approach, our findings contribute to a deeper understanding of pediatric pLGGs, underscoring the need for personalized treatment strategies and vigilant follow-up.

Radiomics and artificial intelligence applications in pediatric brain tumors

BACKGROUND

The study of central nervous system (CNS) tumors is particularly relevant in the pediatric population because of their relatively high frequency in this demographic and the significant impact on disease- and treatment-related morbidity and mortality. While both morphological and non-morphological magnetic resonance imaging techniques can give important information concerning tumor characterization, grading, and patient prognosis, increasing evidence in recent years has highlighted the need for personalized treatment and the development of quantitative imaging parameters that can predict the nature of the lesion and its possible evolution. For this purpose, radiomics and the use of artificial intelligence software, aimed at obtaining valuable data from images beyond mere visual observation, are gaining increasing importance. This brief review illustrates the current state of the art of this new imaging approach and its contributions to understanding CNS tumors in children.

DATA SOURCES

We searched the PubMed, Scopus, and Web of Science databases using the following key search terms: ("radiomics" AND/OR "artificial intelligence") AND ("pediatric AND brain tumors"). Basic and clinical research literature related to the above key research terms, i.e., studies assessing the key factors, challenges, or problems of using radiomics and artificial intelligence in pediatric brain tumors management, was collected.

RESULTS

A total of 63 articles were included. The included ones were published between 2008 and 2024. Central nervous tumors are crucial in pediatrics due to their high frequency and impact on disease and treatment. MRI serves as the cornerstone of neuroimaging, providing cellular, vascular, and functional information in addition to morphological features for brain malignancies. Radiomics can provide a quantitative approach to medical imaging analysis, aimed at increasing the information obtainable from the pixels/voxel grey-level values and their interrelationships. The "radiomic workflow" involves a series of iterative steps for reproducible and consistent extraction of imaging data. These steps include image acquisition for tumor segmentation, feature extraction, and feature selection. Finally, the selected features, via training predictive model (CNN), are used to test the final model.

CONCLUSIONS

In the field of personalized medicine, the application of radiomics and artificial intelligence (AI) algorithms brings up new and significant possibilities. Neuroimaging yields enormous amounts of data that are significantly more than what can be gained from visual studies that radiologists can undertake on their own. Thus, new partnerships with other specialized experts, such as big data analysts and AI specialists, are desperately needed. We believe that radiomics and AI algorithms have the potential to move beyond their restricted use in research to clinical applications in the diagnosis, treatment, and follow-up of pediatric patients with brain tumors, despite the limitations set out.

Investigating distinct clinical features and constructing a nomogram model for survival probability in adults with cerebellar high-grade gliomas

BACKGROUND

The clinical features of cerebellar high-grade gliomas (cHGGs) in adults have not been thoroughly explored. This large-scale, population-based study aimed to comprehensively outline these traits and construct a predictive model.

METHODS

Patient records diagnosed with gliomas were collected from various cohorts and analyzed to compare the features of cHGGs and supratentorial HGGs (sHGGs). Cox regression analyses were employed to identify prognostic factors for overall survival and to develop a nomogram for predicting survival probabilities in patients with cHGGs. Multiple machine learning methods were applied to evaluate the efficacy of the predictive model.

RESULTS

There were significant differences in prognosis, with SEER-cHGGs showing a median survival of 7.5 months and sHGGs 14.9 months (p < 0.001). Multivariate Cox regression analyses revealed that race, WHO grade, surgical procedures, radiotherapy, and chemotherapy were independent prognostic factors for cHGGs. Based on these factors, a nomogram was developed to predict 1-, 3-, and 5-year survival probabilities, with AUC of 0.860, 0.837, and 0.810, respectively. The model's accuracy was validated by machine learning approaches, demonstrating consistent predictive effectiveness.

CONCLUSIONS

Adult cHGGs are distinguished by distinctive clinical features different from those of sHGGs and are associated with an inferior prognosis. Based on these risk factors affecting cHGGs prognosis, the nomogram prediction model serves as a crucial tool for clinical decision-making in patient care.

National multicentered retrospective review of clinical and intraoperative factors associated with the development of cerebellar mutism after pediatric posterior fossa tumor resection

BACKGROUND

Cerebellar mutism (CM) is characterized by a significant loss of speech in children following posterior fossa (PF) surgery. The biological origin of CM remains unclear and is the subject of ongoing debate. Significant recovery from CM is less likely than previously described despite rigorous multidisciplinary neuro-rehabilitational efforts.

METHODS

A national multi-centered retrospective review of all children undergoing PF resection in four midsized Canadian academic pediatric institutions was undertaken. Patient, tumor and surgical factors associated with the post-operative development of CM were reviewed. Retrospective identification of PF surgery patients including those developing and those that did not (internal control).

RESULTS

The study identified 258 patients across the 4 centers between 2010 and 2020 (mean age 6.73 years; 42.2% female). Overall, CM was experienced in 19.5% of patients (N = 50). Amongst children who developed CM histopathology included medulloblastoma (35.7%), pilocytic astrocytoma (32.6%) and ependymoma (17.1%). Intraoperative impression of adherence to the floor of the 4th ventricle was positive in 36.8%. Intraoperative abrupt changes in blood pressure and/or heart rate were identified in 19.4% and 17.8% of cases. The clinical resolution of CM was rated to be complete, significant resolution, slight improvement, no improvement and deterioration in 56.0%, 8.0%, 20.0%, 14.0% and 2.0%, respectively. In the cohort of children who experienced post-operative CM as compared to their no-CM counterpart, proportionally more tumors were felt to be adherent to the floor of the 4th ventricle (56.0% vs 49.5%), intraoperative extent of resection was a GTR (74% vs 68.8%) and changes in heart rate were noted (≥ 20% from baseline) (26.0% vs 15.9%). However, a multiple regression analysis identified only abrupt changes in HR (OR 5.97, CI (1.53, 23.1), p = 0.01) to be significantly associated with the development of post-operative CM.

CONCLUSION

As a devastating surgical complication after posterior fossa tumor surgery with variable clinical course, identifying and understanding the operative cues and revising intraoperative plans that optimizes the child's neurooncological and clinical outcome are essential.

The long-term impact of cerebellar tumor resection on executive functioning, anxiety, and fear of pain: A mixed methodology pilot study

This pilot study investigated the long-term impact of a surgery-only treatment (no exposure to other treatments, such as chemotherapy and radiation) for pediatric cerebellar low-grade gliomas on executive function, anxiety, and fear of pain (FOP) beliefs. Twelve patients who underwent surgical glioma resection during childhood (surgery age was 4-16 years, study visit age was 10-28 years), and 12 pain-free controls matched for age, sex, race, and handedness were tested. The spatial extent of resection was precisely mapped using magnetic resonance imaging (MRI). Executive function, anxiety, and FOP were assessed using validated self-report age-appropriate questionnaires for children and adults. Structured clinical interviews at a post-surgery follow-up visit were completed (average: 89 months, range: 20-99). No significant differences in FOP (FOPQ-C t[14 = 1.81, p = 0.09; FOPQ-III t[4] = 0.29, p = 0.79), executive function scores (BRIEF t[20] = 0.30, p = 0.28), or anxiety scores (MASC t[16] = 0.19, p = 0.85; MAQ t[4] = 1.80, p = 0.15) were found in pediatric or adult patients compared to pain-free controls. Clinical interviews mainly categorized pediatric patients as not anxious. One participant reported mild/subclinical anxiety, and one had moderate clinical anxiety. Neither psychologists nor patients endorsed impairments to executive functioning, anxiety, or FOP. Our pilot results suggest that pediatric cerebellar tumor survivors treated with surgery-only have favorable long-term functioning related to these themes. While these results are promising, they will need to be replicated in a larger patient sample.

Cerebellar pilocytic astrocytoma. Retrospective cohort study assessing postoperative functional outcome, cerebellar mutism and hydrocephalus

Objective

Analyze a series of pediatric patients with cPAs evaluating factors that may modify or determine the final outcome in terms of neurological status, CMS and hydrocephalus.

Materials and methods

Single Center, retrospective cohort study of surgical patients with cPA and at least 12 months of follow-up. Clinical, imaging and surgical features, histopathology and adjuvancy were assessed. Clinical outcome was categorized using the FSS and modified Bloom-Scale in the short and long term. Recurrency, PFS and mortality were also analyzed.

Results

A total of 100 patients with a mean follow-up of 53.9 months, with no gender predilection, and a mean age of 7.6 years were included. The most frequent location was central and 24% of the tumors presented brainstem invasion. 79 patients had hydrocephalus at diagnosis and 48% required preoperative treatment. RT was achieved in 67% of cases. CMS was observed in 15 patients, statistically associated with location, pontine invasion, preoperative Bloom-score, and postoperative meningitis/ventriculitis. The functional "outcome" was correlated with complications such as meningitis/ventriculitis and cerebellar hematoma, mutism and recurrence. Recurrence was observed in 26% of cases and surgical reintervention was the chosen therapy.

Conclusion

The treatment of cPAs in pediatric patients is associated with relatively favorable results. Recurrence, CMS and surgical complications play a prognostic value in the outcome and therefore must be managed appropriately. Early treatment with the intention of GTR should be considered, opting, if this is not possible, to leave a tumor residue over neurological damage. The treatment of hydrocephalus in the preoperative instance requires individualized management.

Posterior fossa tumors in children: An update and new concepts

Background:

Posterior fossa tumors account for approximately half of the central nervous system tumors in children. Major technological advances, mainly in the fields of molecular biology and neuroimaging, have modified their classification, leading to a more detailed description of these entities. Into the classic taxonomy, used for many years, new concepts have been incorporated at times eliminating or modifying former ones.

Methods:

A literature search was conducted in PubMed using the medical subject headings involving the five most common pediatric posterior fossa tumors: diffuse midline glioma, medulloblastoma, ependymoma, atypical teratoid/rhabdoid tumor, and pilocytic astrocytoma. Only English published articles in the past 11 years that provided technological, neuroimaging, and molecular biology insight into posterior fossa tumors in children were considered.

Results:

Substantial changes have been introduced in the nomenclature of pediatric posterior fossa tumors. Diffuse midline gliomas are named based on alterations in histone H3. Molecular rearrangements of medulloblastomas are more important in defining the prognosis than histological variants; therefore, these tumors are currently named based on their molecular subgroups. Posterior fossa ependymomas and atypical teratoid rhabdoid tumor classification have incorporated new groups based on different genetic profiles. Pilocytic astrocytoma has been placed in a new category that distinguishes circumscribed from diffuse entities.

Conclusion:

Advances in molecular biology and neuroimaging have substantially changed the way pediatric neoplasms are studied. The classical taxonomy has been modified leading to more accurate classifications that are based on the genetic alterations.

Update for astrocytomas: medical and surgical management considerations

Astrocytomas include a wide range of tumors with unique mutations and varying grades of malignancy. These tumors all originate from the astrocyte, a star-shaped glial cell that plays a major role in supporting functions of the central nervous system (CNS), including blood-brain barrier (BBB) development and maintenance, water and ion regulation, influencing neuronal synaptogenesis, and stimulating the immunological response. In terms of epidemiology, glioblastoma (GB), the most common and malignant astrocytoma, generally occur with higher rates in Australia, Western Europe, and Canada, with the lowest rates in Southeast Asia. Additionally, significantly higher rates of GB are observed in males and non-Hispanic whites. It has been suggested that higher levels of testosterone observed in biological males may account for the increased rates of GB. Hereditary syndromes such as Cowden, Lynch, Turcot, Li-Fraumeni, and neurofibromatosis type 1 have been linked to increased rates of astrocytoma development. While there are a number of specific gene mutations that may influence malignancy or be targeted in astrocytoma treatment, O 6-methylguanine-DNA methyltransferase (MGMT) gene function is an important predictor of astrocytoma response to chemotherapeutic agent temozolomide (TMZ). TMZ for primary and bevacizumab in the setting of recurrent tumor formation are two of the main chemotherapeutic agents currently approved in the treatment of astrocytomas. While stereotactic radiosurgery (SRS) has debatable implications for increased survival in comparison to whole-brain radiotherapy (WBRT), SRS demonstrates increased precision with reduced radiation toxicity. When considering surgical resection of astrocytoma, the extent of resection (EoR) is taken into consideration. Subtotal resection (STR) spares the margins of the T1 enhanced magnetic resonance imaging (MRI) region, gross total resection (GTR) includes the margins, and supramaximal resection (SMR) extends beyond the margin of the T1 and into the T2 region. Surgical resection, radiation, and chemotherapy are integral components of astrocytoma treatment.

The Utility of Intraoperative Magnetic Resonance Imaging in the Resection of Cerebellar Hemispheric Pilocytic Astrocytomas: A Cohort Study

BACKGROUND

The mainstay of treatment for cerebellar pilocytic astrocytomas in the pediatric population is surgery. The use of intraoperative magnetic resonance imaging (iMRI) as a surgical adjunct may lower the likelihood of reoperation. Studies have examined iMRI in heterogenous tumor populations, but few have looked at single pathologies.

OBJECTIVE

To compare iMRI vs non-iMRI for hemispheric cerebellar pilocystic astrocytomas, specifically looking at revision surgeries and residual disease in follow-up.

METHODS

Retrospective review of medical records for 60 sequential patients with cerebellar hemispheric pilocytic astrocytoma at a single institution was conducted. Thirty-two patients with cerebellar pilocytic astrocytoma underwent surgery without iMRI, whereas 28 patients underwent surgical resection with iMRI. All patients had at least 3-year follow-up.

RESULTS

There were no significant differences between the patient populations in age, tumor size, or need for cerebrospinal fluid diversion between groups. Operative time was shorter without iMRI (without iMRI 4.4 ± 1.3 hours, iMRI 6.1 ± 1.5, P = .0001). There was no significant difference in the patients who had repeat surgery within 30 days (9% without iMRI, 0% iMRI, P = .25), residual disease at 3 months (19% without iMRI, 14% iMRI, P = .78), or underwent a second resection beyond 30 days (9% without iMRI, 4% iMRI, P = .61). There were more total reoperations in the group without iMRI, although this did not reach significance (19% vs 4%, P = .11).

CONCLUSION

For hemispheric cerebellar pilocytic astrocytomas, iMRI tended to leave less residual and fewer reoperations; however, neither of these outcomes achieved statistical significance leaving utilization to be determined by the surgeon.

Ataxia and mobility in children following surgical resection of posterior fossa tumour: A longitudinal cohort study

PURPOSE

To report the course of ataxia in children up to 2 years post-operatively, following surgical resection of a posterior fossa tumour (PFT).

METHODS

Thirty-five children, (median age 9 years, range 4-15) having resection of PFT, were assessed using the Scale for the Assessment and Rating of Ataxia (SARA), Brief Ataxia Rating Scale (BARS) and the mobility domain of the Paediatric Evaluation of Disability Index (PEDI-m) at initial post-operative period (baseline), 3 months, 1 year and 2 years post-operatively.

RESULTS

Baseline median scores of the SARA and BARS were 8.5 (range 0-35.5), and 7 (0-25) respectively. Ataxia improved at 3 months (median SARA and BARS reduction 3.5 and 4, respectively). Additional gradual improvements in SARA were recorded at 1 (median reduction 2) and 2 years post-operatively (median reduction 0.5). Median baseline PEDI-m was 54.75 (range 15.2-100) with improvement at 3 months (median increase 36.95) and small improvement at 1 year (median increase 2.5) and 2 years (median increase 5.8). Children with medulloblastoma and midline tumours (median baseline SARA 10 and 11, respectively) demonstrated more severe ataxia than children with low-grade gliomas and unilateral tumours (median baseline SARA 7.5 and 6.5, respectively).

CONCLUSION

The largest improvement in ataxia scores and functional mobility scores is demonstrated within the first 3 months post-operatively, but ongoing gradual improvement is observed at 2 years. Children with medulloblastoma and midline tumour demonstrated higher ataxia scores long term.

Mapping of long-term cognitive and motor deficits in pediatric cerebellar brain tumor survivors into a cerebellar white matter atlas

PURPOSE

Diaschisis of cerebrocerebellar loops contributes to cognitive and motor deficits in pediatric cerebellar brain tumor survivors. We used a cerebellar white matter atlas and hypothesized that lesion symptom mapping may reveal the critical lesions of cerebellar tracts.

METHODS

We examined 31 long-term survivors of pediatric posterior fossa tumors (13 pilocytic astrocytoma, 18 medulloblastoma). Patients underwent neuronal imaging, examination for ataxia, fine motor and cognitive function, planning abilities, and executive function. Individual consolidated cerebellar lesions were drawn manually onto patients' individual MRI and normalized into Montreal Neurologic Institute (MNI) space for further analysis with voxel-based lesion symptom mapping.

RESULTS

Lesion symptom mapping linked deficits of motor function to the superior cerebellar peduncle (SCP), deep cerebellar nuclei (interposed nucleus (IN), fastigial nucleus (FN), ventromedial dentate nucleus (DN)), and inferior vermis (VIIIa, VIIIb, IX, X). Statistical maps of deficits of intelligence and executive function mapped with minor variations to the same cerebellar structures.

CONCLUSION

We identified lesions to the SCP next to deep cerebellar nuclei as critical for limiting both motor and cognitive function in pediatric cerebellar tumor survivors. Future strategies safeguarding motor and cognitive function will have to identify patients preoperatively at risk for damage to these critical structures and adapt multimodal therapeutic options accordingly.

The use and efficacy of chemotherapy and radiotherapy in children and adults with pilocytic astrocytoma

PURPOSE

The aim of this study was to understand the use of chemotherapy (CMT) and radiotherapy (RT) in pilocytic astrocytoma (PA) and their impact on overall survival (OS).

METHODS

Data from the National Cancer Database (NCDB) for patients with non-metastatic WHO grade I PA from 2004 to 2014 were analyzed. Pearson's chi-squared test and multivariate logistic regression analyses were performed to assess the distribution of demographic, clinical, and treatment factors. Inverse probability of treatment weighting (IPTW) was used to account for differences in baseline characteristics. Kaplan-Meier analyses and doubly-robust estimation with multivariate Cox proportional hazards modeling were used to analyze OS.

RESULTS

Of 3865 patients analyzed, 294 received CMT (7.6%), 233 received RT (6.0%), and 42 (1.1%) received both. On multivariate analyses, decreasing extent of surgical resection was associated with receipt of both CMT and RT. Brainstem tumors were associated with RT, optic nerve tumors were associated with CMT. Cerebellar tumors were inversely associated with both CMT and RT. Younger age was associated with receipt of CMT; conversely, older age was associated with receipt of RT. After IPTW, receipt of CMT and/or RT were associated with an OS decrement compared with matched patients treated with surgery alone or observation (HR 3.29, p < 0.01).

CONCLUSIONS

This is the largest study to date to examine patterns of care and resultant OS outcomes in PA. We identified patient characteristics associated with receipt of CMT and RT. After propensity score matching, receipt of CMT and/or RT was associated with decreased OS.

Long-term cognitive deficits in pediatric low-grade glioma (LGG) survivors reflect pretreatment conditions-report from the German LGG studies

Background

Disease and treatment contribute to cognitive late effects following pediatric low-grade glioma (LGG). We analyzed prospectively collected neuropsychological data of German pediatric LGG survivors and focused on the impact of hydrocephalus at diagnosis, neurofibromatosis type 1 (NF1) status, and extent of surgery.

Methods

We used the Neuropsychological Basic Diagnostic screening tool based on the Cattell-Horn-Carroll model for intelligence and the concept of cross-battery assessment at 2 and 5 years from diagnosis for 316 patients from the German pediatric LGG study and LGG registry (7.1 years median age; 45 NF1; cerebral hemispheres 16%, supratentorial midline 39%, infratentorial 45%). Hydrocephalus was classified radiologically in 137 non-NF1 patients with infratentorial tumors (95/137 complete/subtotal resection).

Results

Patients with NF1 versus non-NF1 exhibited inferior verbal short-term memory and visual processing (P < .001-.021). In non-NF1 patients, infratentorial tumor site and complete/subtotal resection were associated with sequelae in visual processing, psychomotor speed, and processing speed (P < .001-.008). Non-NF1 patients without surgical tumor reduction and/or nonsurgical treatment experienced similar deficits. Degree of hydrocephalus at diagnosis had no further impact. Psychomotor and processing speed were impaired comparably following chemo-/radiotherapy (P < .001-.021). Pretreatment factors such as NF1 or tumor site were relevant at multivariate analysis.

Conclusions

All pediatric LGG survivors are at risk to experience long-term cognitive impairments in various domains. Even surgical only management of cerebellar LGG or no treatment at all, that is, biopsy only/radiological diagnosis did not protect cognitive function. Since pattern and extent of deficits are crucial to tailor rehabilitation, neuropsychological and quality of survival assessments should be mandatory in future LGG trials.

Efficacy of surgery for the treatment of astrocytoma: A protocol of systematic review and meta-analysis

BACKGROUND

This study will assess the efficacy of surgery for the treatment of patients with astrocytoma.

METHODS

We will undertake searches for randomized controlled trials from the following databases: MEDLINE, EMBASE, Cochrane Library, CINAHL, PsycINFO, and China National Knowledge Infrastructure. We will search all these databases from their inception to the March 1, 2020. No language limitation and publication status will be imposed in this study. Two authors will independently carry out study selection, data extraction, and study quality assessment. We will invite another author to solve any divergences between 2 authors. We will use RevMan 5.3 software to conduct statistical analysis.

RESULTS

This study will present synthesis of most recent evidence of surgery for the treatment of patients with astrocytoma.

CONCLUSION

The findings of this study will provide helpful reference for the efficacy and complications of surgery for the treatment of patients with astrocytoma to the clinicians and future researchers.

STUDY REGISTRATION

INPLASY202040194.

Posterior Fossa Society Consensus Meeting 2018: a synopsis

PURPOSE

The Posterior Fossa Society (PFS) was founded 4 years ago to systematically gather and exchange information on the post-operative (CMS) and cerebellar cognitive affective syndrome (CCAS). With its consensus meetings, the PFS orchestrates research studies in the field of cerebellar injury and progresses the knowledge of post-operative pediatric cerebellar mutism syndrome (CMS). In this article, we captured the 3-day program of presentations, group discussions, interactive workshops, and dialogue, highlighting the key topic areas of CMS and its research advances.

METHODS

This synopsis is based on the third consensus meeting which was held in Reykjavik, Iceland, in August 2018.

RESULTS

Three working groups have been defined to drive the future research priorities on post-surgical CMS: (i) refining definition and symptoms scoring of CMS; (ii) understanding the pathogenesis and enhancing risk-stratification strategies; and (iii) developing rehabilitation approaches and protocols.

CONCLUSIONS

The third consensus meeting highlighted a unanimous desire for data-driven information to advance the knowledge and guide future research efforts. The PFS constitutes an established and expanding network of multi-disciplinary expertise that can facilitate the development of collaborative studies and produce official guidelines on the topic.

Diagnostic accuracy of apparent diffusion coefficient ratio in distinguishing common pediatric CNS posterior fossa tumors

Background

Pilocytic astrocytoma, medulloblastoma, and ependymoma are the most common pediatric CNS tumors seen at posterior cranial fossa and final diagnosis obtained by histopathology after surgical excision. Routine MRI study gives an idea about site and extension of the tumors but provide a little information about type and grade of tumors. ADC ratio had high sensitivity and specificity in differentiation between these tumors as regard type and grade according to tumor cellularity.

Patients and methods

Prospective study conducted on thirty pediatric patients (11 males and 19 females) with CNS posterior fossa masses, their ages ranged from 2 to 17 years (mean age of 8.7 years), conventional MRI, DWI, ADC value, and ADC ratio were done for all patients.

Results

ADC values were significantly different between pilocytic astrocytomas (1.43 ± 0.28 × 10−3) and medulloblastomas (0.71 ± 0. 21 × 10−3) with a P value < 0.001, also there was a significant difference when comparing medulloblastomas (0.71 ± 0.21 × 10−3) with ependymomas (1.04 × 10−3 ± 0.21) with a P value < 0.001. ADC ratio at a cutoff > 1.7 showed significant good power of discrimination of astrocytoma (AUC = 0.85) from ependymoma with 87.5% sensitivity and 93.3% specificity. Similarly, at cutoff ≤ 1.6-> 1.2 was a significant good predictor of ependymoma (AUC = 0.85) with 87.8% sensitivity and 99.5% specificity. While, ADC ratio ≤ 1.2 was significant excellent discriminator of medulloblastoma (AUC = 0.99) with 100% sensitivity and 90% specificity.

Conclusion

ADC ratio is a simple way used in distinguishing juvenile pilocytic astrocytoma, ependymoma, and medulloblastoma, which are the most frequent pediatric posterior fossa tumors. Cutoff ADC ratio of more than 1.7 characteristic of JPA with 87.5% sensitivity and 93.3% specificity, ADC ratio less than 1.1 characteristic of medulloblastoma with 100% sensitivity and 90% specificity. ADC ratios more than 1.1 and less than 1.7 characteristic of ependymoma with 87.8% sensitivity and 99.5% specificity. We recommended ADC ratio as a routine study in evaluation of pediatric CNS posterior fossa tumors.

Copy number assessment in the genomic analysis of CNS neoplasia: An evidence-based review from the cancer genomics consortium (CGC) working group on primary CNS tumors

The period from the 1990s to the 2010s has witnessed a burgeoning sea change in the practice of surgical neuropathology due to the incorporation of genomic data into the assessment of a range of central nervous system (CNS) neoplasms. This change has since matured into the adoption of genomic information into the definition of several World Health Organization (WHO)-established diagnostic entities. The data needed to accomplish the modern diagnosis of CNS neoplasia includes DNA copy number aberrations that may be assessed through a variety of mechanisms. Through a review of the relevant literature and professional practice guidelines, here we provide a condensed and scored overview of the most critical DNA copy number aberrations to assess for a selection of primary CNS neoplasms.

Peripheral retinal neovascularization in a patient with pilocytic astrocytoma

We described a case of papilledema complicated by peripheral retinal vessels in a 12-year-old boy affected by cerebellar astrocytoma. Opportunity to treat with photocoagulation or intravitreal anti-VEGF (vascular endothelial growth factor) injections was discussed with the parents and no treatment was done. After 5 years from surgery, retinal neovascularization was stable without vitreal hemorrhages or retinal complications, more specifically fibrosis of the neovessels increased and leakage phenomena were reduced at the fluorescein angiography. To our knowledge, this is a unique case of papilledema complicated by peripheral retinal vessels in a patient affected by cerebellar astrocytoma.

Pediatric cerebellar pilocytic astrocytoma presenting with spontaneous intratumoral hemorrhage

Pilocytic astrocytomas (PAs) are benign glial tumors and one of the most common childhood posterior fossa tumors. Spontaneous intratumoral hemorrhage in PAs occurs occasionally, in about 8-20% of cases. Cerebellar hemorrhages in pediatric population are rare and mainly due to head injuries, rupture of vascular malformations, infections, or hematological diseases. We have investigated the still controversial and unclear pathophysiology underlying intratumoral hemorrhage in PAs. Bleeding in low-grade tumors might be related to structural abnormalities and specific angio-architecture of tumor vessels, such as degenerative mural hyalinization, "glomeruloid" endothelial proliferation, presence of encased micro-aneurysms, and glioma-induced neoangiogenesis. The acute hemorrhagic presentation of cerebellar PA in childhood although extremely uncommon is of critical clinical importance and necessitates promptly treatment. We described a case of hemorrhagic cerebellar PA in a 9-year-old child and reviewed the English-language literature that reported spontaneous hemorrhagic histologically proven cerebellar PA in pediatric patients (0-18 years). According to our analysis, the mortality was not related to symptom onset, tumor location, hemorrhage distribution, presence of acute hydrocephalous, and timing of surgery, while the GCS at hospital admission resulted to be the only statistically significant prognostic factor affecting survival outcome. The abrupt onset of signs and symptoms of acute hydrocephalous and consequent raised intracranial pressure are life-threatening conditions, which need emergent medical and neurosurgical treatments. At a later time, the identification of posterior fossa hemorrhage etiology is crucial to select the appropriate treatment and address the surgical strategy, optimizing the postoperative results.

A low-grade astrocytoma in a sixteen-year-old boy with a 7q11.22 deletion

We report a patient with developmental delay due to germline AUTS2 mutation who developed a low‐grade astrocytoma. While the contribution of this mutation to the pathogenesis of the tumor is not known at this time, a role of AUTS2 in deregulation of PRC1 can be a part in tumorigenesis of a brain tumor.

Hemorrhagic presentation of intracranial pilocytic astrocytomas: literature review

Pilocytic astrocytomas (PAs) are seemingly innocuous and benign tumors. However, in recent times, many case series have documented high rates of hemorrhage in these neoplasms. We hereby provide a detailed analysis on hemorrhagic pilocytic astrocytomas (HPA) in adults and report one such case managed at our institute. In addition, salient differences between adult and pediatric hemorrhagic PA have been briefed. Hospital records were retrieved for our case. Literature review was conducted by searching online databases for the following keywords-pilocytic astrocytoma, hemorrhage, cranial, pediatric, and adults. A 22-year-old male with neurofibromatosis-1 presented with sudden onset headache and vomiting of 3-day duration. Imaging revealed a lobulated suprasellar lesion with obstructive hydrocephalus. Pterional transsylvian approach and subtotal resection were performed. Histopathology showed features of PA with bleed. Including current report, a total of 26 cases have been reported. Mean age was 37 years (21-75 years) and they are mostly found in the third decade. The male:female ratio was 2.1:1. Sudden headache with vomiting was the most common symptoms. Tumors were mostly located in cerebral hemispheres (n = 9/34.6%), hypothalamus/suprasellar region (n = 7/27%), and cerebellum (n = 6/23%). Two-thirds underwent gross total excision. There were two deaths and except one case, no recurrences were reported in those with available follow-ups. Hemorrhagic presentation of a PA is rare, although more commonly seen in adults and most commonly located in cerebral hemispheres. Maximal safe resection is the standard treatment and recurrences are rare.

Visual and ocular motor outcomes in children with posterior fossa tumors

PURPOSE

To describe the clinical characteristics and visual and ocular motor outcomes of a large cohort of pediatric patients treated for tumors of the posterior cranial fossa.

METHODS

The medical records of all patients with posterior fossa tumors evaluated by the ophthalmology services at two large tertiary care academic hospitals between 2005 and 2011 were reviewed retrospectively. Data abstracted for each study patient included demographic information, presenting signs and symptoms, pathologic diagnosis, and results of the most recent ophthalmology examination.

RESULTS

A total of 139 patients were included. Visual outcomes were categorized as "good" (bilateral acuity of 20/20-20/40) in 101 patients (72.7%), "fair" (<20/40-20/200 in one or both eyes) in 12 patients (8.6%), or "poor" (<20/200 in one or both eyes) in 9 patients (6.5%). Patients with medulloblastoma and ependymoma had a significantly greater risk of a poor or fair visual outcome than those with juvenile pilocytic astrocytoma (both P < 0.05), independent of age and sex. Thirty-two patients (23.0%) developed nystagmus, and 59 patients (42.4%) developed strabismus. Twenty-four patients (17.3%) underwent eye muscle surgery for persistent strabismus.

CONCLUSIONS

The majority of patients had good visual outcomes, although ocular motor abnormalities were common. Tumor type was a significant risk factor for permanent vision loss.

A Review of Visual and Oculomotor Outcomes in Children With Posterior Fossa Tumors

Tumors of the posterior fossa represent the most common solid malignancy of childhood and can affect the visual system in several ways. This article outlines the relevant visual anatomy affected by these tumors and reviews the visual and oculomotor outcomes associated with the following 3 most common tumor types-medulloblastoma, juvenile pilocytic astrocytoma, and ependymoma. The available data suggest that the rate of permanent vision loss is low (5.9%-8.3%), with patients having juvenile pilocytic astrocytoma demonstrating the best outcomes. The rate of long-term strabismus (25%-29.1%) and nystagmus (12.5%-18%) is higher and associated with significant morbidity.

Cerebellar Mutism Syndrome following Midline Posterior Fossa Tumor Resection in Children: An Institutional Experience

Aim:

Cerebellar mutism (CM) syndrome is a well-known and annoying complication of posterior fossa surgery in the pediatric age group. Risk factors such as the type of tumor, size, involvement of posterior fossa structures and hydrocephalus, and postoperative cerebellar swelling for CM were investigated in this study.

Materials and Methods:

A consecutive series of 33 children with midline posterior fossa tumors were operated at the SMS Medical College and Hospital, Department of Neurosurgery, Jaipur India, between September 2015 and December 2016. Their speech and neuroradiological studies were systematically analyzed both preoperatively and postoperatively.

Results:

CM syndrome (CMS) developed in six children (18.18%) in the early postoperative period. The pre- and post-operative irritability, medulloblastoma histology, maximum size more than 45 mm, involvement of superior cerebellar peduncles, and vermian incision were significant single independent risk factors. In addition, male gender also associated with a higher risk for CMS. The latency for the development of mutism ranged from 1 to 12 days (mean 3.5 days). The speech returned to normal in all patients. All cases with CMS accompanied by cerebellar ataxia.

Conclusion:

The medulloblastoma, irritability, maximum size more than 45 mm, involvement of superior cerebellar peduncles, and vermian incision were significant single independent risk factors for postoperative pediatric CMS. Mutism after posterior fossa tumor resection is also accompanied with ataxia. CM usually has a self-limiting course and a favorable prognosis.

Preoperative neurocognitive evaluation as a predictor of brain tumor grading in pediatric patients with supratentorial hemispheric tumors

OBJECTIVE

The objective of the present study was to retrospectively evaluate the relationship between tumor grading and a selective evaluation of neurocognitive and behavioral functions in children with supratentorial hemispheric brain tumors.

METHODS

Children admitted with a diagnosis of supratentorial hemispheric tumors involving the cerebral hemispheres or the thalamus at the Pediatric Neurosurgery Unit of the Catholic University of Rome between January 2008 and January 2014 were considered for the present study. Exclusion criteria were represented by age less than 2 years, severe neurological deficits, seizures, and a metastatic disease. A selective neurocognitive and behavioral workout was used for children aged less and more than 5 years.

RESULTS

Global cognitive functions as well as selective neurocognitive and behavioral profiles were found to be significantly worse in children with low-grade tumors, compared with those affected by higher-grades histotypes. Frontal locations for cortical tumors and thalamic lesions were significantly related with worse results, with a clear contribution of dominant vs. nondominant hemisphere involvement and an age higher than 5 years.

CONCLUSIONS

Preoperative global and selective neurocognitive evaluation might contribute to the prediction of the tumor aggressiveness. Due to a longer clinical history, more benign tumors more frequently arrive to the diagnosis with a neurocognitive compromise in spite of an apparently mild presence of neurological symptoms and signs.

Consensus paper on post-operative pediatric cerebellar mutism syndrome: the Iceland Delphi results

INTRODUCTION

Confusion has surrounded the description of post-operative mutism and associated morbidity in pediatric patients with cerebellar tumors for years. The heterogeneity of definitions and diagnostic features has hampered research progress within the field, and to date, no international guidelines exist on diagnosis, prevention, treatment, or follow-up of this debilitating condition. An international group of clinicians and researchers from multiple relevant disciplines recently formed a cohesive panel to formulate a new working definition and agree upon standardized methods for diagnosis and follow-up.

METHODS

Consensus was obtained using the modified nominal group technique, involving four rounds of online Delphi questionnaires interspersed with a structured consensus conference with lectures, group work, and open discussion sessions.

RESULTS

A new, proposed definition of "post-operative pediatric CMS" was formed, preliminary recommendations for diagnostic and follow-up procedures were created, two working groups on a new scoring scale and risk prediction and prevention were established, and areas were identified where further information is needed.

DISCUSSION

The consensus process was motivated by desire to further research and improve quality of life for pediatric brain tumor patients. The Delphi rounds identified relevant topics and established basic agreement, while face-to-face engagement helped resolve matters of conflict and refine terminology. The new definition is intended to provide a more solid foundation for future clinical and research work. It is thought as a consensus for moving forward and hopefully paves the way to developing a standard approach to this challenging problem with the advent of better scoring methods and ultimate goal of reducing the risk of CMS.