Outcome of Patients With Pilocytic Astrocytoma and Leptomeningeal Dissemination

Continuous response despite reduced dose of trametinib as single agent in an adolescent with a relapsed disseminated pediatric low-grade glioma KIAA1549-BRAF fusion positive: a case report and review of the literature

Dissemination in pediatric low-grade glioma may occur in about 4%-10% of patients according to retrospective cohort studies. Due to its low incidence, there is no consensus on treatment for these patients. According to the constitutional activation of the MAPK/ERK pathway in these tumors, MEK inhibitors such as trametinib have been used successfully in the relapsed setting. Skin toxicity is frequent in patients receiving trametinib, normally mild to moderate, but sometimes severe, needing to discontinue the drug, limiting the efficacy in the tumor. There is not much information in the literature regarding whether reducing the dose of trametinib is able to maintain efficacy while, at the same time, decreasing toxicity. Here, we present an adolescent, with severe skin toxicity, whose trametinib dose was reduced by 50% and efficacy on the tumor continued while skin toxicity significantly decreased.

Comparison of the clinical features and treatment outcomes of pilocytic astrocytoma in pediatric and adult patients

PURPOSE

Pilocytic astrocytoma is a slow-growing tumor that predominantly develops in children, but has a broad age spectrum. A notable characteristic of pilocytic astrocytoma is that the tumor arises in diverse locations and the clinical course is not always benign. Therefore, it is necessary to elucidate the clinical spectrum of the disease and analyze the relevant prognostic factors.

METHODS

Demographic and treatment-related factors were retrospectively reviewed in a cohort of 254 patients with histologically confirmed pilocytic astrocytoma. Clinical features were compared between the pediatric group (N = 208; age < 18 years) and the adult group (N = 46; age ≥ 18 years). Cox regression analysis was performed to identify relevant prognostic factors.

RESULTS

There was no difference in progression-free survival (PFS) between the pediatric and adult groups (p = 0.36); however, patients under 8 years of age exhibited worse PFS (p < 0.01). Leptomeningeal seeding at diagnosis and pilomyxoid histology was observed only in pediatric patients. In the pediatric group, nine patients experienced recurrence after complete resection. Increasing age (hazard ratio (HR) = 0.89, p < 0.01) and adjuvant therapy (HR = 0.32, p < 0.01) were protective factors against tumor progression. In the adult group, no progression occurred after complete resection. Age and adjuvant therapy were not significant factors in the adult group.

CONCLUSION

Pilocytic astrocytoma presents with a diverse clinical spectrum. Complete resection is of utmost importance, and appropriate adjuvant treatment is recommended if complete resection cannot be achieved. Children with younger age are associated with more aggressive tumors, and recurrence may occur even after complete resection.

Rare Neuronal, Glial and Glioneuronal Tumours in Adults

Rare glial, neuronal and glioneuronal tumours in adults form a heterogeneous group of rare, primary central nervous system tumours. These tumours, with a glial and/or neuronal component, are challenging in terms of diagnosis and therapeutic management. The novel classification of primary brain tumours published by the WHO in 2021 has significantly improved the diagnostic criteria of these entities. Indeed, diagnostic criteria are nowadays multimodal, including histological, immunohistochemical and molecular (i.e., genetic and methylomic). These integrated parameters have allowed the specification of already known tumours but also the identification of novel tumours for a better diagnosis.

DNA methylation array analysis for diffuse leptomeningeal glioneuronal tumor with conspicuous hypothalamic mass. A case report

Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a rare glioneuronal neoplasm newly included in the 2016 World Health Organization Classification of Tumors of the Central Nervous System. Owing to the wide spectrum of its histopathological and radiological features, accurate diagnosis can be challenging. Recently, molecular testing including DNA methylation array has been introduced with the possibility of improving diagnostic accuracy and contributing to the subtyping especially for brain tumors with ambiguous histology. Two molecularly distinct subtypes of DLGNT have been reported: methylation class-1 (MC-1) with an indolent clinical course and MC-2, the latter aggressive. Herein, we report a case of a 14-year-old girl with a conspicuous hypothalamic mass lesion and diffuse leptomeningeal enhancement on magnetic resonance imaging. Biopsy specimens obtained from the hypothalamic lesion endoscopically were mainly composed of oligodendrocyte-like cells. However, it was difficult to make a definite diagnosis from these non-specific histological findings. Thus, DNA methylation array analysis was performed additionally by using formalin-fixed, paraffin-embedded tissue, resulting in a diagnosis of "MC-1 subtype of DLGNT" with a high calibrated score (0.99). Consequently, she was treated conservatively, with neither progression of the tumor nor aggravation of symptoms for the next 12 months. It was concluded that DNA methylation array analysis for DLGNT, a rare glioneuronal tumor, could be a powerful tool not only for accurate diagnosis but also decision-making in selecting the best treatment.

Recurrent adult pilocytic astrocytoma presenting with intraventricular and leptomeningeal spread

Background

Infratentorial pilocytic astrocytomas are uncommon tumors in adulthood but are thought to be prognostically similar to their pediatric counterparts with excellent overall survival following gross total resection. However, given the relative rarity of these tumors, no management guidelines exist for recurrent adult pilocytic astrocytomas (APAs). This lack of consensus is especially problematic for inoperable recurrences or those with aggressive features concerning for malignant transformation.

Case Description

In 2017, a 26-year-old female presented with headaches, nausea, vomiting, and blurry vision. A brain magnetic resonance imaging (MRI) demonstrated a large, well-circumscribed mass within the fourth ventricle causing obstructive hydrocephalus. She underwent near-total resection through a midline suboccipital transtonsillar approach. Pathology demonstrated a World Health Organization Grade 1 pilocytic astrocytoma. Despite initial improvement in her symptoms, she developed worsening headaches and lethargy 10 months after surgery and repeat MRI demonstrated recurrent tumor within the entire ventricular system and the subarachnoid spaces of the left cerebellopontine angle suggesting leptomeningeal spread. Due to the unresectable nature of the recurrence, the patient declined any further intervention and succumbed to her disease 6 months later.

Conclusion

We present the first case of a recurrent APA presenting with intraventricular and leptomeningeal spread. Although thought to be a benign neoplasm, close interval follow-up with serial imaging is of essential, especially in those patients with known residual tumor, to prevent aggressive recurrences such as this.

Dissemination Patterns and Short-Term Management of Multifocal Rosette-Forming Glioneuronal Tumors

BACKGROUND

Multifocal rosette-forming glioneuronal tumors (RGNTs) are challenging to manage. Gross total resection is often impossible, and data on adjunctive therapies are limited. We reviewed cases of multifocal RGNTs in the literature with special focus on dissemination patterns and management.

METHODS

A literature review was conducted using PubMed and the key words "(multifocal OR multicentric OR satellite OR dissemination) AND glioneuronal."

RESULTS

There were 21 cases of multifocal RGNTs identified. Follow-up was available in 18 cases at a median of 17 months. Progression-free survival and overall survival at 1 year were 84% and 94%, respectively. Of all cases, 43% had cerebrospinal fluid (CSF) dissemination, 48% had intraparenchymal spread, and 10% had both. The presence of CSF dissemination led to palliative care and/or death in 20% of cases (n = 2). None of the cases with intraparenchymal spread progressed. Radiotherapy was used in 50% of cases with CSF dissemination, chemotherapy was used in 20%, and CSF shunting was used in 36%. No tumors with intraparenchymal spread required adjunctive therapy or shunting.

CONCLUSIONS

RGNTs with CSF dissemination are more likely to behave aggressively, and early adjunctive therapies should be discussed with patients. Tumors with intraparenchymal spread grow slowly, and maximal safe resection followed by observation is likely sufficient in the short term. Long-term behavior of multifocal RGNTs is still unclear.

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.

The role of screening spinal MRI in children with solitary posterior fossa low-grade glial tumors

OBJECTIVE

Solitary posterior fossa low-grade glial tumors (SPFLGT) in children are rarely associated with leptomeningeal dissemination (LMD). To date, there are no clear guidelines regarding the role of screening and surveillance spinal MRI (sMRI) in children with SPFLGT, at diagnosis or during follow-up periods. The current study reviews a cohort of children with SPFLGT, focusing on sMRI findings.

METHODS

In this binational retrospective study, the authors analyzed 229 patients with SPFLGT treated and followed over 13 years. One hundred twelve children had at least 1 total sMRI screening or surveillance examination. One hundred seventeen had no sMRI, but did not present with clinical spinal signs or symptoms. Collected data included demographics, disease characteristics, radiology, pathology, and clinical follow-up data.

RESULTS

For the 112 children with at least 1 sMRI, the mean duration from diagnosis to first sMRI was 11.73 ± 28.66 months (range 0-165 months). All sMRI scans were conducted as screening examinations, with no spinal-related symptoms. One patient was found to have a sacral intradural lesion concurrent to the brain tumor diagnosis. Over the course of 180 radiological and 533 clinical follow-up years for the 112 patients with sMRI, and 582 clinical follow-up years for the 117 patients with no sMRI, there were no additional cases with spinal tumor spread.

CONCLUSIONS

The yield of screening sMRI in the absence of cranial metastasis, or spinal symptoms, is extremely low. Because preoperative sMRI is recommended for medulloblastomas and ependymomas, it may be logical to acquire. During the follow-up period the authors recommend limiting sMRI in patients without symptoms suggesting a spinal lesion, in patients without known cranial metastases, or recurrence or residual SPFLGT.

Radiotherapy in the Management of Paediatric Low-Grade Gliomas

Paediatric low-grade (World Health Organization grade I-II) gliomas (LGGs) represent a spectrum of primary central nervous system tumours. Local tumour control is the cornerstone in the general management of childhood gliomas. Surgery is the primary treatment of choice in the majority. Non-surgical treatments are recommended for progressive or symptomatic inoperable disease. Although chemotherapy is increasingly used as first non-surgical treatment, radiotherapy remains standard as salvage treatment or as primary treatment in selected cases in which surrounding normal tissue can be optimally preserved. The role of targeted therapies is currently under investigation in clinical trials. Modern high-precision radiotherapy techniques, including proton therapy, have the potential to improve long-term toxicities. There is therefore an urgent need for prospective studies to compare the efficacy and safety of modern radiotherapy with systemic treatment in children with LGGs. New information on molecular genetic patterns in LGGs may also have an impact on the selection and sequencing of radiotherapy.

Outcomes in children with central nervous system tumors disseminated at presentation: a large single-center experience

PURPOSE

Children with disseminated central nervous system (CNS) tumors have worse outcomes than those with solitary disease, but outcomes of disease dissemination at initial presentation have not been systematically studied and compared across tumor groups to date. We evaluated the impact of tumor dissemination at presentation on management and clinical outcomes in a cohort of consecutively treated children in a single neurosurgical unit over a 14-year period.

METHODS

Method used was a retrospective review of data on children presenting to Great Ormond Street Hospital, London, UK, with medulloblastoma, primitive neuroectodermal tumor, atypical teratoid rhabdoid tumor, pilocytic astrocytoma, and ependymoma between 2003 and 2016 inclusive. Uni- and multi-variate analyses were performed to evaluate a range of outcome measures.

RESULTS

Three-hundred sixty-one children were identified in total, 53 with disease dissemination at presentation (M:F = 34:19, median age = 3.8 years, range = 7 days-15.6 years) and 308 with solitary tumors (M:F = 161:147, median age = 5.8 years, range = 1 day-16.9 years). Median follow-up was similar irrespective of dissemination status (disseminated tumor 64.0 months, range = 5.2-152.0 months; solitary tumor 74.5 months, range = 4.7-170.1 months; P > 0.05). In multivariate analyses, tumor type and dissemination status at presentation were significantly associated with overall survival (P < 0.0001), risk of recurrence/disease progression (P < 0.01), and event-free survival (P < 0.0001). Subtotal resection was associated with shorter time to recurrence/disease progression (P < 0.01) and worse event-free (P < 0.0001) but not overall survival, whereas treatment with chemotherapy and radiotherapy were associated with improved overall (Ps < 0.0001) and event-free survival (Ps < 0.05). Differences between tumor groups were evident.

CONCLUSIONS

Dissemination status at initial presentation significantly affects outcomes in children with CNS tumors.

Surgical decision-making in the management of childhood tumors of the CNS disseminated at presentation

OBJECTIVE It is relatively unusual for pediatric CNS tumors to be disseminated at presentation, and the literature on the clinical features, management, and outcomes of this specific group is scarce. Surgical management in this population is often challenging, particularly in the presence of hydrocephalus. The authors present their recent experience of treating pediatric CNS tumors that were disseminated at presentation, and they compare these lesions with focal tumors. METHODS The authors performed a retrospective review of prospectively collected data on children presenting to a tertiary center between 2003 and 2016 inclusive. RESULTS Of 361 children with CNS tumors, the authors identified 53 patients with disease dissemination at presentation (male/female ratio 34:19, median age 3.8 years, age range 7 days to 15.6 years) and 308 without dissemination at presentation (male/female ratio 161:147, median age 5.8 years, age range 1 day to 16.9 years). Five tumor groups were studied: medulloblastoma (disseminated n = 29, focal n = 74), other primitive neuroectodermal tumor (n = 8, n = 17), atypical teratoid rhabdoid tumor (n = 8, n = 22), pilocytic astrocytoma (n = 6, n = 138), and ependymoma (n = 2, n = 57). The median follow-up duration in survivors was not significantly different between those with disease dissemination at presentation (64.0 months, range 5.2-152.0 months) and those without it (74.5 months, range 4.7-170.1 months) (p > 0.05). When combining data from all 5 tumor groups, dissemination status at presentation was significantly associated with a higher risk of requiring CSF diversion, a higher surgical complication rate, and a reduced likelihood of achieving gross-total resection of the targeted lesion (all variables p < 0.05). Differences between the 5 tumor groups were evident. No factors that predicted the need for permanent CSF diversion following temporary external ventricular drainage were identified on multivariate analysis, and there was no clear superiority of either ventriculoperitoneal shunt surgery or endoscopic third ventriculostomy as a permanent CSF diversion procedure. CONCLUSIONS Tumor type and dissemination status at initial presentation significantly affect outcomes across a range of measures. The management of hydrocephalus in patients with CNS tumors is challenging, and further prospective studies are required to identify the optimal CSF diversion strategy in this population.

Clinical responses of patients with diffuse leptomeningeal glioneuronal tumors to chemotherapy

INTRODUCTION

Diffuse leptomeningeal glioneuronal tumors (DLGT) have been recognized in the most recent WHO classification as a distinct entity.

OBJECTIVE

We describe seven pediatric cases of DLGT and the responses to therapy and outcome.

METHODS

We conducted a retrospective review of charts from 1985 to 2013.

RESULTS

DBS is an effective therapeutic modality for intractable TLE, particularly in patients with lateralized EEG A total of seven patients were identified. Median age at diagnosis was 3 years. Three months was the median time from symptom development to diagnosis. Common MRI findings included diffuse leptomeningeal thickening, nodularity, or coating of the subarachnoid or ependymal surfaces. The leptomeningeal lesions often appear cystic and contrast enhancement was variable. Six patients had leptomeningeal involvement of the brain and spine. All patients had a negative CSF cytology. Biopsies demonstrated thickened meninges infiltrated by a monotonous population of oligodendrocyte-like cells. Immunohistochemistry revealed variable features of neuronal and/or glial differentiation. All samples were negative for BRAF V600E mutation by immunohistochemistry. Therapy included one patient treated with craniospinal irradiation followed by vincristine, etoposide, cyclophosphamide, and cisplatin with stable disease for 164 months. Six patients received carboplatin and vincristine with a median duration of response of 20+ months (15-122+). Three patients received temozolomide upfront and progressed at 3, 4, and 27 months. No patients demonstrated complete or partial responses to any chemotherapy regimens. Progression-free survival ranged from 3 to 164+ months; 4/7 patients remained free of progression. All patients are alive.

CONCLUSIONS

DLGT are rare tumors that lack imaging responses; however, there was clinical/ symptom improvement in 100% of the patients. A better understanding of the tumor biology is necessary to improve the diagnosis and treatment of this rare disease.

SIOP PODC Adapted treatment guidelines for low grade gliomas in low and middle income settings

Effective treatment of children with low grade glioma (LGG) requires a functioning multi-disciplinary team with adequate neurosurgical, neuroradiological, pathological, radiotherapy and chemotherapy facilities and personnel. In addition, the treating centre should have the capacity to manage a variety of LGG and treatment-associated complications. These requirements have made it difficult for many centers in low and middle-income countries (LMIC) to offer effective treatment and follow up. This article provides management recommendations for children with LGG according to the level of facilities available.

MR imaging of brain pilocytic astrocytoma: beyond the stereotype of benign astrocytoma

BACKGROUND

Pilocytic astrocytoma (PA) is the most common pediatric brain glioma and is considered the prototype of benign circumscribed astrocytoma. Despite its low malignancy, the CT and MRI features of brain PA may resemble those of much more aggressive brain tumors. Misdiagnosis of PA is particularly easy when it demonstrates MR morphological and non-morphological findings that are inconsistent with its non-aggressive nature and that overlap with the features of more aggressive brain tumors.

METHOD

Basing on the evidence that the variation in the histological, genetic, and metabolic "fingerprint" for brain PA is dependent on tumor location, and the hypothesis that tumor location is related to the broad spectrum of morphological and non-morphological MR imaging findings, the authors discuss the MR imaging appearance of brain PA using a location-based approach to underline the typical and less typical imaging features and the main differential diagnosis of brain PA. A brief summary of the main pathological and clinical features, the natural history, and the treatment of brain PA is also provided.

RESULT

A combination of morphological and non-morphological MR imaging features and a site-based approach to differential diagnosis are required for a pre-operative diagnosis. The new "cutting-edge" MR imaging sequences have the potential to impact the ease and confidence of pediatric brain tumor interpretation and offer a more efficient diagnostic work-up.

CONCLUSIONS

Although the typical imaging features of brain pilocytic astrocytoma make radiological diagnosis relatively easy, an atypical and more aggressive appearance can lead to misdiagnosis. Knowing the broad spectrum of imaging characteristics on conventional and advanced MR imaging is important for accurate pre-operative radiological diagnosis and correctly interpreting changes during follow-up.

Leptomeningeal dissemination and vertebral bone involvement in a child with pilocytic astrocytoma

In low-grade glioma, metastasis is rarely seen. Few cases of leptomeningeal dissemination have been reported in children. Vertebral bone metastasis has not been reported so far. Herein is described the case of a pediatric patient with the diagnosis of pilocytic astrocytoma, and leptomeningeal dissemination detected at the time of diagnosis, who then received radiotherapy and chemotherapy upon development of vertebral bone metastasis during treatment.

Suprasellar pilocytic astrocytoma in an adult with hemorrhage and leptomeningeal dissemination: case report and review of literature

Pilocytic astrocytoma (PA) is a low-grade tumor. It has an excellent prognosis after total resection. Leptomeningeal dissemination and hemorrhage are very rare to be associated with PA and lead to unfavorable prognosis. A 35-year-old man was diagnosed with a hemorrhagic suprasellar PA in 2006. Subsequent examination in 2007 revealed another large subdural hemorrhagic lesion in the sacral region, which proved to be PA by histopathologic assessment. Other leptomeningeal foci were discovered mainly at the craniocervical junction. The patient underwent subtotal resection and received chemotherapy with disease control for 7 years. Progression of the disseminated disease has recently occurred; however, the patient is still alive with stable disease after radiotherapy. The radiological features, management, and relevant literature are also presented. Our report heightens the awareness of PA in the adult population and the importance of close surveillance for the leptomeningeal spread, especially for sellar region tumors.

Metastatic Low-Grade Gliomas in Children: 20 Years' Experience at St. Jude Children's Research Hospital

BACKGROUND

Patients with low-grade gliomas (LGG), which are the most common childhood brain tumors, have excellent long-term survival. Dissemination of LGG is rare. Robust data on the incidence, presentation, patterns of dissemination, disease behavior, outcome, and best-management approaches do not exist. We describe 20 years of follow-up of children with metastatic LGG.

PROCEDURE

Data collected during the period 1990-2010 were retrospectively reviewed for the following inclusion criteria: diagnosis of metastatic LGG, age younger than 21 years at initial diagnosis, and magnetic resonance imaging of the brain and/or spine at diagnosis and/or follow-up. Patient demographics, pathology, treatment modalities, and outcome were reviewed.

RESULTS

Of 599 patients with LGG, 38 (6%) had metastatic disease at either diagnosis or follow-up. Most tumors (87%) were located in the brain, and half of the patients had metastatic disease at presentation. The most common diagnosis was pilocytic astrocytoma (55%). Chemotherapy was the most common initial treatment modality. Median survival of the group was 6.2 years (range, 0.1-16.9 years). Fifteen (40%) patients died at a median of 6 years from diagnosis (range, 0.8-15 years). Overall survival at 5, 10, and 15 years was 80.7 ± 6.6%, 63.0 ± 10.2%, and 50.9 ± 16.0%, respectively.

CONCLUSION

This study describes the longest follow-up of children with metastatic LGG. LGG is underestimated and entails major morbidity and mortality. Prospective studies are needed to learn the true incidence, study the biology, and determine the best approaches to diagnosis, treatment, and follow-up.

Model-Based Evaluation of Spontaneous Tumor Regression in Pilocytic Astrocytoma

Pilocytic astrocytoma (PA) is the most common brain tumor in children. This tumor is usually benign and has a good prognosis. Total resection is the treatment of choice and will cure the majority of patients. However, often only partial resection is possible due to the location of the tumor. In that case, spontaneous regression, regrowth, or progression to a more aggressive form have been observed. The dependency between the residual tumor size and spontaneous regression is not understood yet. Therefore, the prognosis is largely unpredictable and there is controversy regarding the management of patients for whom complete resection cannot be achieved. Strategies span from pure observation (wait and see) to combinations of surgery, adjuvant chemotherapy, and radiotherapy. Here, we introduce a mathematical model to investigate the growth and progression behavior of PA. In particular, we propose a Markov chain model incorporating cell proliferation and death as well as mutations. Our model analysis shows that the tumor behavior after partial resection is essentially determined by a risk coefficient γ, which can be deduced from epidemiological data about PA. Our results quantitatively predict the regression probability of a partially resected benign PA given the residual tumor size and lead to the hypothesis that this dependency is linear, implying that removing any amount of tumor mass will improve prognosis. This finding stands in contrast to diffuse malignant glioma where an extent of resection threshold has been experimentally shown, below which no benefit for survival is expected. These results have important implications for future therapeutic studies in PA that should include residual tumor volume as a prognostic factor.

An individual patient data meta-analysis on characteristics, treatments and outcomes of the glioblastoma/gliosarcoma patients with central nervous system metastases reported in literature until 2013

Dissemination of high-grade gliomas (WHO IV) has been investigated poorly so far. We conducted an extensive analysis of the characteristics, treatments and outcomes of the glioblastoma multiforme (GBM)/gliosarcoma (GS) patients with central nervous system (CNS) metastases reported in literature until April 2013. PubMed and Web of Science searches for peer-reviewed articles pertaining to GBM/GS patients with metastatic disease were conducted using predefined keywords. Additionally, we performed hand search following the references from the selected papers. Cases in which the metastases exclusively occurred outside the CNS were excluded. 110 publications reporting on 189 patients were eligible. There was a significant increase in the number of reported cases over the last decades. We calculated a median overall survival from diagnosis of metastasis (from initial diagnosis of GBM/GS) of 3.0 ± 0.3 (11 ± 0.7) months. On univariate analyses, gender, age, the histological subtype, the time interval between initial diagnosis and the occurrence of metastases and the location of CNS metastasis (intracranial versus spinal and parenchymal versus leptomeningeal, respectively) did not influence survival after diagnosis of metastasis. There was no substantial treatment progress over the recent decades. GBM/GS with CNS metastasis are associated with a dismal prognosis. Crucial treatment progress is not evident. A central registry should be considered to consecutively gain more information about the ideal therapeutic approach.

An individual patient data meta-analysis on characteristics and outcome of patients with papillary glioneuronal tumor, rosette glioneuronal tumor with neuropil-like islands and rosette forming glioneuronal tumor of the fourth ventricle

Background and Purpose

In 2007, the WHO classification of brain tumors was extended by three new entities of glioneuronal tumors: papillary glioneuronal tumor (PGNT), rosette-forming glioneuronal tumor of the fourth ventricle (RGNT) and glioneuronal tumor with neuropil-like islands (GNTNI). Focusing on clinical characteristics and outcome, the authors performed a comprehensive individual patient data (IPD) meta-analysis of the cases reported in literature until December 2012.

Methods

PubMed, Embase and Web of Science were searched for peer-reviewed articles reporting on PGNT, RGNT, and GNTNI using predefined keywords.

Results

95 publications reported on 182 patients (PGNT, 71; GNTNI, 26; RGNT, 85). Median age at diagnosis was 23 years (range 4–75) for PGNT, 27 years (range 6–79) for RGNT, and 40 years (range 2–65) for GNTNI. Ninety-seven percent of PGNT and 69% of GNTNI were located in the supratentorial region, 23% of GNTNI were in the spinal cord, and 80% of RGNT were localized in the posterior fossa. Complete resection was reported in 52 PGNT (73%), 36 RGNT (42%), and 7 GNTNI (27%) patients. Eight PGNT, 3 RGNT, and 12 GNTNI patients were treated with chemo- and/or radiotherapy as the primary postoperative treatment. Follow-up data were available for 132 cases. After a median follow-up time of 1.5 years (range 0.2–25) across all patients, 1.5-year progression-free survival rates were 52±12% for GNTNI, 86±5% for PGNT, and 100% for RGNT. The 1.5-year overall-survival were 95±5%, 98±2%, and 100%, respectively.

Conclusions

The clinical understanding of the three new entities of glioneuronal tumors, PGNT, RGNT and GNTNI, is currently emerging. The present meta-analysis will hopefully contribute to a delineation of their diagnostic, therapeutic, and prognostic profiles. However, the available data do not provide a solid basis to define the optimum treatment approach. Hence, a central register should be established.

Adult pilocytic astrocytomas: clinical features and molecular analysis

BACKGROUND

Adult pilocytic astrocytomas (PAs) are rare and have an aggressive clinical course compared with pediatric patients. Constitutive Ras/RAF/MAPK signaling appears to be an important oncogenic event in sporadic PA. We evaluated clinical data and molecular profiles of adult PAs at our institution.

METHODS

We identified 127 adult PAs in our institutional database. Cases with available tissue were tested for BRAF-KIAA1549 fusion/duplication (B-K fusion) by fluorescence in situ hybridization and submitted for mutation profiling using the Sequenom mutation profiling panel. Subgroup analyses were performed based on clinical and molecular data.

RESULTS

The majority of adult PAs are supratentorial. Twenty-two percent of cases had an initial pathologic diagnosis discordant with the diagnosis made at our institution. Recurrence was seen in 42% of cases, and 13% of patients died during follow-up. Adjuvant radiotherapy following surgical resection was associated with a statistically significant decrease in progression-free survival (P = .004). B-K fusion was identified in 20% (9 of 45) of patients but was not associated with outcome. No BRAF V600E mutations (0 of 40 tested) were found.

CONCLUSION

This was the largest single institution series of adult PA. A significant proportion of adult PAs follow an aggressive clinical course. Our results support a period of observation following biopsy or surgical resection. B-K fusion in adult PA does not influence outcome, and BRAF V600E mutation appears to be a very rare event. Further study of tumor biology and optimal treatment is needed, given a more aggressive clinical behavior.

Pediatric low-grade gliomas: how modern biology reshapes the clinical field

Low-grade gliomas represent the most frequent brain tumors arising during childhood. They are characterized by a broad and heterogeneous group of tumors that are currently classified by the WHO according to their morphological appearance. Here we review the clinical features of these tumors, current therapeutic strategies and the recent discovery of genomic alterations characteristic to these tumors. We further explore how these recent biological findings stand to transform the treatment for these tumors and impact the diagnostic criteria for pediatric low-grade gliomas.

Definitive treatment of leptomeningeal spinal metastases in children

BACKGROUND

Uniquely in children, the existence of leptomeningeal spinal metastases does not confer a uniformly grave prognosis. Although the radiation tolerance of the spinal cord is of significant concern in these cases, the chemo- and radiosensitivity of these lesions argues for an aggressive approach where possible.

METHODS

The records of the Indiana University Health Proton Therapy Center were reviewed for patients undergoing proton beam therapy with curative intent for LSM between January 1, 2004 and July 7, 2012. Patients with microscopic disease only on LP were not included. Particulars of therapy, including dose, field sizes, toxicities, and outcomes were collated.

RESULTS

Twenty-two children received therapy as described, of median age 5 years (range 1.1-17.1). Patients had medulloblastoma (n = 9), ATRT (n = 4), ependymoma, and PNET (n = 3 each). Five lesions (23%) were chemo-recurrent, though no patient had prior radiation to the spine. Median follow-up was 14 months (range 4-33) for all living patients. Fifteen (68%) children continued to have local control at last follow-up visit. Median dose was 37.8 Gy (range 21.6-54 Gy). Eight patients with chemo-recurrent disease or diffuse cord seeding did poorly, with local control and overall survival achieved in four. The 12-month overall survival was 68% with grade 1 skin erythema as the most frequent toxicity.

CONCLUSIONS

We describe a cohort of LSM patients treated with RT with definitive intent, and the only available data from the proton environment. Durable response is possible for these children in over two-thirds of cases. Significant toxicity was infrequent using proton radiotherapy and these fractionation schemes.

Evaluation of the sellar and parasellar regions

The article reviews the anatomy and imaging evaluation of the sellar and parasellar regions. Both common and uncommon sellar and suprasellar masses are reviewed, focusing on a systematic approach to analysis and when appropriate, differential creation.