Development of A Radiomic Model for MGMT Promoter Methylation Detection in Glioblastoma Using Conventional MRI.

The methylation of the O6-methylguanine-DNA methyltransferase (MGMT) promoter is a molecular marker associated with a better response to chemotherapy in patients with glioblastoma (GB). Standard pre-operative magnetic resonance imaging (MRI) analysis is not adequate to detect MGMT promoter methylation. This study aims to evaluate whether the radiomic features extracted from multiple tumor subregions using multiparametric MRI can predict MGMT promoter methylation status in GB patients. This retrospective single-institution study included a cohort of 277 GB patients whose 3D post-contrast T1-weighted images and 3D fluid-attenuated inversion recovery (FLAIR) images were acquired using two MRI scanners. Three separate regions of interest (ROIs) showing tumor enhancement, necrosis, and FLAIR hyperintensities were manually segmented for each patient. Two machine learning algorithms (support vector machine (SVM) and random forest) were built for MGMT promoter methylation prediction from a training cohort (196 patients) and tested on a separate validation cohort (81 patients), based on a set of automatically selected radiomic features, with and without demographic variables (i.e., patients' age and sex). In the training set, SVM based on the selected radiomic features of the three separate ROIs achieved the best performances, with an average of 83.0% (standard deviation: 5.7%) for accuracy and 0.894 (0.056) for the area under the curve (AUC) computed through cross-validation. In the test set, all classification performances dropped: the best was obtained by SVM based on the selected features extracted from the whole tumor lesion constructed by merging the three ROIs, with 64.2% (95% confidence interval: 52.8-74.6%) accuracy and 0.572 (0.439-0.705) for AUC. The performances did not change when the patients' age and sex were included with the radiomic features into the models. Our study confirms the presence of a subtle association between imaging characteristics and MGMT promoter methylation status. However, further verification of the strength of this association is needed, as the low diagnostic performance obtained in this validation cohort is not sufficiently robust to allow clinically meaningful predictions.

Significance and clinical suggestions for the somatosensory evoked potentials increased in amplitude revealed by a large sample of neurological patients.

OBJECTIVES: To investigate the relationship between N20-P25 peak-to-peak amplitude (N20p-P25p) of somatosensory evoked potentials (SEPs) and the occurrence of abnormalities of the peripheral and/or central sensory pathways and of myoclonus/epilepsy, in 308 patients with increased SEPs amplitude from upper limb stimulation. METHODS: We compared cortical response (N20p-P25p) in different groups of patients identified by demographic, clinical, and neurophysiological factors and performed a cluster analysis for classifying the natural occurrence of subgroups of patients. RESULTS: No significant differences of N20p-P25p were found among different age-dependent groups, and in patients with or without PNS/CNS abnormalities of sensory pathways, while myoclonic/epileptic patients showed higher N20p-P25p than other groups. Cluster analysis identified four clusters of patients including myoclonus/epilepsy, central sensory abnormalities, peripheral sensory abnormalities, and absence of myoclonus and sensory abnormalities. CONCLUSIONS: Increased N20p-P25p prompts different possible pathophysiological substrates: larger N20p-P25p in patients with cortical myoclonus and/or epilepsy is likely sustained by strong cortical hyperexcitability, while milder increase of N20p-P25p could be underpinned by plastic cortical changes following abnormalities of sensory pathways, or degenerative process involving the cortex. SEPs increased in amplitude cannot be considered an exclusive hallmark of myoclonus/epilepsy. Indeed, in several neurological disorders, it may represent a sign of adaptive, plastic, and/or degenerative cortical changes.

MYD88 L265P mutation and interleukin-10 detection in cerebrospinal fluid are highly specific discriminating markers in patients with primary central nervous system lymphoma: results from a prospective study.

Reliable biomarkers are needed to avoid diagnostic delay and its devastating effects in patients with primary central nervous system (CNS) lymphoma (PCNSL). We analysed the discriminating sensitivity and specificity of myeloid differentiation primary response (88) (MYD88) L265P mutation (mut-MYD88) and interleukin-10 (IL-10) in cerebrospinal fluid (CSF) of both patients with newly diagnosed (n = 36) and relapsed (n = 27) PCNSL and 162 controls (118 CNS disorders and 44 extra-CNS lymphomas). The concordance of MYD88 mutational status between tumour tissue and CSF sample and the source of ILs in PCNSL tissues were also investigated. Mut-MYD88 was assessed by TaqMan-based polymerase chain reaction. IL-6 and IL-10 messenger RNA (mRNA) was assessed on PCNSL biopsies using RNAscope technology. IL levels in CSF were assessed by enzyme-linked immunosorbent assay. Mut-MYD88 was detected in 15/17 (88%) PCNSL biopsies, with an 82% concordance in paired tissue-CSF samples. IL-10 mRNA was detected in lymphomatous B cells in most PCNSL; expression of IL-6 transcripts was negligible. In CSF samples, mut-MYD88 and high IL-10 levels were detected, respectively, in 72% and 88% of patients with newly diagnosed PCNSL and in 1% of controls; conversely, IL-6 showed a low discriminating sensitivity and specificity. Combined analysis of MYD88 and IL-10 exhibits a sensitivity and specificity to distinguish PCNSL of 94% and 98% respectively. Similar figures were recorded in patients with relapsed PCNSL. In conclusion, high detection rates of mut-MYD88 and IL-10 in CSF reflect, respectively, the MYD88 mutational status and synthesis of this IL in PCNSL tissue. These biomarkers exhibit a very high sensitivity and specificity in detecting PCNSL both at initial diagnosis and relapse. Implications of these findings in patients with lesions unsuitable for biopsy deserve to be investigated.

High tumor mutational burden and T-cell activation are associated with long-term response to anti-PD1 therapy in Lynch syndrome recurrent glioblastoma patient.

BACKGROUND: Glioblastomas (GBMs) in patients harboring somatic or germinal mutations of mismatch-repair (MMR) genes exhibit a hypermutable phenotype. Here, we describe a GBM patient with increased tumor mutational burden and germline MMR mutations, treated using anti-PD1 therapy. METHODS: A woman with newly diagnosed GBM (nGBM) was treated by surgery, radiotherapy, and temozolomide. The tumor recurred after 13 months leading to a second surgery and treatment with nivolumab. Whole-exome sequencing was performed on the nGBM, recurrent GBM (rGBM), and blood. Immune infiltration was investigated by immunohistochemistry and the immune response in the blood during treatment was analyzed by flow cytometry. RESULTS: High density of infiltrating CD163 + cells was found in both GBM specimens. Large numbers of CD3 + and CD8 + T cells were homogeneously distributed in the nGBM. The infiltration of CD4 + T cells and a different CD8 + T cell density were observed in the rGBM. Both GBM shared 12,431 somatic mutations, with 113 substitutions specific to the nGBM and 1,683 specific to the rGBM. Germline variants included pathogenic mutation in the MSH2 (R359S) gene, suggesting the diagnosis of Lynch syndrome. Systemic immunophenotyping revealed the generation of CD8 + T memory cells and persistent activation of CD4 + T cells. The patient is still receiving nivolumab 68 months after the second surgery. CONCLUSIONS: Our observations indicate that the hypermutator phenotype associated with germinal mutations of MMR genes and abundant T-cell infiltration contributes to a durable clinical benefit sustained by a persistent and robust immune response during anti-PD1 therapy.

Medulloblastoma of the adult: results from a multicenter retrospective study by AINO (Italian Association of Neuro-Oncology) and SIN (Italian Society of Neurology).

INTRODUCTION: Medulloblastoma (MB) is the most common primary malignant intracranial tumor in childhood, but it is very rare in adults, and for this reason, the optimal treatment has not yet been defined. We designed a multicentric study in order to define relevant outcome measures for future prospective studies. MATERIALS AND METHODS: The project involved 10 Italian centers. The database shared among the centers contains epidemiological, diagnostic (radiological and histological/molecular), therapeutic, recurrence information, and survival data. RESULTS: A total of 152 patients (102 males and 50 females, median age 32) were included in the study. Twenty-three of 152 patients had a diagnosis of classic medulloblastoma, 52/152 had desmoplastic/extensive nodularity, 2/152 had large-cell anaplastic medulloblastoma, and the remaining had diagnoses not otherwise specified. Almost all patients underwent craniospinal irradiation after surgery; in 85.5% of patients, adjuvant chemotherapy, mainly platinum- and etoposide-based chemotherapy, was performed immediately after RT. Upon recurrence, most patients were retreated with various chemotherapy regimens, including intrathecal chemotherapy in patients with leptomeningeal dissemination. The overall survival (OS) rate at 5 years was 73.3% (95% CI, 65.0-80.0%). The median OS for the whole group of patients was 112 months. CONCLUSIONS: The data collected were mainly consistent with the literature. A limitation of this study was the large number of patients lost to follow-up and the lack of molecular data for most patients diagnosed until 2010. An important challenge for the future will be MB biologic characterization in adults, with the identification of specific genetic patterns. It will be important to have more national and international collaborations to provide evidence-based management strategies that attempt to obtain a standard of care.

Neuro-telehealth for fragile patients in a tertiary referral neurological institute during the COVID-19 pandemic in Milan, Lombardy.

BACKGROUND: Lombardy was severely hit by the COVID-19 pandemic since February 2020 and the Health System underwent rapid reorganization. Outpatient clinics were stopped for non-urgent patients: it became a priority to manage hundreds of fragile neurological patients who suddenly had less reference points. In Italy, before the pandemic, Televisits were neither recognized nor priced. METHODS: At the Fondazione IRCCS Istituto Neurologico C. Besta, we reorganized outpatient clinics to deliver Neuro-telemedicine services, including Televisits and Teleneurorehabilitation, since March 2020. A dedicated Working Group prepared the procedure, tested the system, and designed satisfaction questionnaires for adults and children. RESULTS: After a pilot phase, we prepared a procedure for Telemedicine outpatient clinics which was approved by hospital directions. It included prescription, booking, consenting, privacy and data protection, secure connection with patients (Teams Microsoft 365), electronic report preparation and delivery, reporting, and accountability of the services. During the March-September 2020 period, we delivered 3167 Telemedicine services, including 1618 Televisits, to 1694 patients (972 adults, 722 children) with a wide range of chronic neurological disorders. We successfully administered different clinical assessment and scales. Satisfaction among patients and caregivers was very high. CONCLUSIONS: During the dramatic emergency, we were able to take care of more than 1600 patients by organizing Neuro-telehealth in a few weeks, lessening the impact of the pandemic on fragile patients with chronic neurological disorders; this strategy is now stably embedded in our care pathways. In Italy, Telehealth is at present recognized and priced and is becoming a stable pillar of the health system.

Gliomatosis cerebri (GC) or GC-like? A picture to be reconsidered in neuro-oncology based on large retrospective analysis of GC series.

INTRODUCTION: Gliomatosis cerebri (GC), defined until 2016 as a distinct astrocytic glioma entity, has been removed from the 2016 World Health Organization classification of tumors of the central nervous system. However, its identity is still debated. MATERIALS AND METHODS: We retrospectively present 122 patients, including a subgroup with histology confirmation (n = 75, cohort b). RESULTS: Radiological features showed extension limited to 3 lobes in 31%; bilateral, midline, and basal ganglia and subtentorial involvement in 95%, 52%, 84%, and 60%, respectively; and contrast enhancement in 59.5%. Perioperative mortality occurred in 4%. Histology concluded for grades II, III, and IV, respectively, in 31%, 35%, and 22% (not specified in 12%). Thirty-one percent had isocitrate dehydrogenase (IDH) 1 mutation. Treatments included radiotherapy in 51.2% and chemotherapy in 74.5%. Median overall survival was 17 months. Negative prognostic factors for survival were older age, poorer Karnofsky Performance Scale (KPS), subtentorial, midline and disseminated disease, and lack of chemotherapy, at univariate analysis. At multivariate analysis, KPS ≥ 80, chemotherapy, and subtentorial and disseminated disease remained prognostic (p < 0.0001). For cohort b, same prognostic factors were confirmed, except for midline location, at univariate analysis; at multivariate analysis, only KPS ≥ 80 and chemotherapy remained prognostic (p < 0.0001). CONCLUSION: We described clinical, neuroimaging, management, and histomolecular features of one of the largest GC series. We identified KPS ≥ 80, radiological pattern as subtentorial localization and dissemination, and chemotherapy as prognostic factors, at multivariate analysis. Planning prospective study, associated to focused genetic assays, could help to clarify if GC has specific features that may result in the identification as a separate entity from other gliomas.

In vivo 2-hydroxyglutarate-proton magnetic resonance spectroscopy (3 T, PRESS technique) in treatment-naïve suspect lower-grade gliomas: feasibility and accuracy in a clinical setting.

Isocitrate dehydrogenase 1/2 (IDH1/2) mutations are often detected in lower-grade gliomas (LGG) and result into 2-hydroxyglutarate (2HG) synthesis. Prior studies showed that 2HG can be detected in vivo using magnetic resonance spectroscopy (MRS), but its accuracy and translational impact are still under investigation. PURPOSE: To investigate the clinical feasibility of MRS for in vivo detection and quantification of 2HG on consecutive treatment-naïve suspect LGG patients and to compare MRS accuracy with tissue IDH1/2 analysis. METHODS: MRS spectra at 3 T were acquired with 1H-MRS single-voxel PRESS 2HG-tailored sequences with TE 30 (group 1) or TE 97 (groups 2A and B). Voxel sizes were 1.5 × 1.5 × 1.5 cm3 for group 1 (n = 13) and group 2A (n = 14) and 2 × 2 × 2 cm3 for group 2B (n = 32). Multiple metabolites' concentrations were analyzed with LCModel. Tumors were assessed for IDH status and main molecular markers. 2HG levels in urine/blood were measured by liquid chromatography-mass spectrometry. RESULTS: The larger voxel TE 97 sequence resulted in highest specificity (100%), sensitivity (79%), and accuracy (87%). Urine and blood 2HG did not result predictive. CONCLUSION: Our data confirm that 2 × 2 × 2-cm3 voxel TE 97 MRS shows high accuracy for 2HG detection, with good sensitivity and 100% specificity in distinguishing IDH mutant gliomas. Main limits of the technique are small tumor volume and low cellularity. Integrating 2HG-MRS with other metabolites may help non-invasive diagnosis of glioma, prognostic assessment, and treatment planning in clinical setting.

ABCC3 Expressed by CD56dim CD16+ NK Cells Predicts Response in Glioblastoma Patients Treated with Combined Chemotherapy and Dendritic Cell Immunotherapy.

Recently, we found that temozolomide (TMZ) can upregulate the expression of the multidrug-resistance protein ABCC3 in NK cells from both glioma-bearing mice and glioblastoma patients treated with dendritic cell immunotherapy combined with TMZ, allowing NK cells to escape apoptosis and favoring their role as antitumor effector cells. Here, we demonstrate that CD56dim NK cells expressing CD16+ are predominant in patients surviving more than 12 months after surgery without disease progression. CD56dim CD16+ NK cells co-expressed high levels of ABCC3 and IFN-. Notably, not only basal but also TMZ-induced ABCC3 expression was related to a strong, long-term NK cell response and a better prognosis of patients. The identification of the single nucleotide polymorphism (SNP) rs35467079 with the deletion of a cytosine (-897DelC) in the promoter region of the ABCC3 gene resulted associated with a better patient outcome. ABCC3 expression in patients carrying DelC compared to patients with reference haplotype was higher and modulated by TMZ. The transcription factor NRF2, involved in ABCC3 induction, was phosphorylated in CD56dim CD16+ NK cells expressing ABCC3 under TMZ treatment. Thus, ABCC3 protein and the SNP -897DelC can play a predictive role in patients affected by GBM, and possibly other cancers, treated with dendritic cell immunotherapy combined with chemotherapy.

Extraneural metastases in glioblastoma patients: two cases with YKL-40-positive glioblastomas and a meta-analysis of the literature.

Glioblastoma (GBM) are high-grade gliomas that severely impact on overall survival (OS). GBM cell motility and the breakdown of the blood-brain barrier could favor GBM cell communication with the systemic circulation. In spite of this, extracranial GBM metastases are rare. Here, we describe two YKL-40-positive GBM patients with extra-CNS (central nervous system) metastases, and we present a meta-analysis of 94 cases. The analysis concluded that extra-CNS metastases occurred 8.5 months after first GBM diagnosis and OS was 12 months; surgical GBM excision was associated at a longer interval to extra-CNS metastasis than biopsy only, and even longer if followed by radiotherapy and chemotherapy. Both our case reports were adult males who developed extra-CNS, YKL-40-positive metastases at lymph nodes, lung and subcutaneous sites, after 86 and 24 months from initial diagnosis of GBM. At first GBM local recurrence, they were treated with bevacizumab (BV), an anti-vascular endothelial growth factor antibody. They died after 4 and 1 month from the occurrence of metastases. Both cases expressed YKL-40 and lacked EGFR amplification, suggesting a mesenchymal phenotype, and maintained such profile at extra-CNS recurrence; they did not show MGMT promoter methylation, IDH1/2 mutations, or c-Met upregulation. Our two cases and the meta-analysis support the idea that prolonged survival of GBM patients increases the probability of GBM cells shedding to lymphatic and hematic system. Interestingly, the present two cases showed the features of mesenchymal profile, usually related with worst prognosis that was maintained in extracranial metastases.

Predictors of survival and effect of short (40 Gy) or standard-course (60 Gy) irradiation plus concomitant temozolomide in elderly patients with glioblastoma: a multicenter retrospective study of AINO (Italian Association of Neuro-Oncology).

The efficacy of temozolomide (TMZ) plus radiation therapy (RT) in elderly patients with glioblastoma is unclear. We performed a large multicenter retrospective study to analyze prognostic factors and clinical outcome in these patients. Inclusion criteria were age ≥65 years, newly histologically confirmed glioblastoma, ECOG PS 0-2, adjuvant treatment with RT plus TMZ. We enrolled 237 patients; the average age was 71 and ECOG PS was 0-1 in 196 patients; gross total resection was performed in 174 cases. MGMT was analyzed in 151 persons and was methylated in 56 %. IDH1 was assessed in 100 patients and was mutated in 6 %. Seventy-one patients were treated with RT 40 Gy and 166 with RT 60 Gy. Progression-free survival and overall survival (OS) were 11.3 and 17.3 months, respectively. Overall survival was 19.4 vs 13.8 months for patients treated with RT 60 Gy and 40 Gy (p = 0.02); OS was 17.7 versus 16.1 months for patients treated with gross total resection vs partial surgery (p = 0.02); OS was 21.2 versus 13.6 months for methylated and unmethylated MGMT (p < 0.001). On multivariate analysis, gross total resection, RT 60 Gy, methylated MGMT and ECOG PS 0-1 were independent predictors of longer survival. Twenty-five patients (10 %) had grade 3-4 haematological toxicity during the concomitant treatment. We showed that, in elderly patients in good clinical condition treated with concomitant treatment, standard-course irradiation might be more effective than short-course irradiation. Methylated MGMT remains the most important prognostic factor.

Fluorescein-guided surgery for malignant gliomas: a review.

Fluorescein is widely used as a fluorescent tracer for many applications. Its capacity to accumulate in cerebral areas where there has been blood-brain barrier damage makes it particularly suitable as a dye for the intraoperative visualization of malignant gliomas (MGs). In this report, we describe the results of a comprehensive review on the use of fluorescein in the surgical treatment of MGs. A comprehensive literature search and review for English-written articles concerning the use of fluorescein in the resection of MGs has been conducted. The search was executed through a PubMed literature search using the following keywords: malignant gliomas, glioblastomas, high-grade gliomas, YELLOW 560, total removal, dedicated filter, neurosurgery, brain tumors, intracranial tumors, and confocal microscopy. The literature search resulted in the retrieval of 412 evidence-based articles. Of these, 17 were found to be strictly related to the resection of MG with the aid of fluorescein. In addition to these 17, we have included 2 articles derived from a personal database of the corresponding author (FA). The analysis of the articles reviewed revealed three major applications of fluorescein during surgery for MGs that was documented: Fluorescein-guided resection of MGs with white-light illumination, fluorescein-guided resection of MGs with a surgical microscope equipped with a dedicated filter for fluorescein, and confocal microscopy for intraoperative histopathological analysis on MGs. The systemic review conducted on the use of fluorescein in MGs explored the applications and the different modalities in which fluorescein has been used. The data we have gathered indicates that fluorescein-guided surgery is a safe, effective, and convenient technique to achieve a high rate of total removal in MGs. Further prospective comparative trials, however, are still necessary to prove the impact of fluorescein-guided surgery on both progression-free survival and overall survival.

Is fluorescein-guided technique able to help in resection of high-grade gliomas?

OBJECT: Fluorescein, a dye that is widely used as a fluorescent tracer, accumulates in cerebral areas where the blood-brain barrier is damaged. This quality makes it an ideal dye for the intraoperative visualization of high-grade gliomas (HGGs). The authors report their experience with a new fluorescein-guided technique for the resection of HGGs using a dedicated filter on the surgical microscope. METHODS: The authors initiated a prospective Phase II trial (FLUOGLIO) in September 2011 with the objective of evaluating the safety of fluorescein-guided surgery for HGGs and obtaining preliminary evidence regarding its efficacy for this purpose. To be eligible for participation in the study, a patient had to have suspected HGG amenable to complete resection of the contrast-enhancing area. The present report is based on the analysis of the short- and long-term results in 20 consecutive patients with HGGs (age range 45-74 years), enrolled in the study since September 2011. In all cases fluorescein (5-10 mg/kg) was injected intravenously after intubation. Tumor resection was performed with microsurgical technique and fluorescence visualization by means of BLUE 400 or YELLOW 560 filters on a Pentero microscope. RESULTS: The median preoperative tumor volume was 30.3 cm(3) (range 2.4-87.8 cm(3)). There were no adverse reactions related to fluorescein administration. Complete removal of contrast-enhanced tumor was achieved in 80% of the patients. The median duration of follow-up was 10 months. The 6-months progression-free survival rate was 71.4% and the median survival was 11 months. CONCLUSIONS: Analysis of these 20 cases suggested that fluorescein-guided technique with a dedicated filter on the surgical microscope is safe and allows a high rate of complete resection of contrast-enhanced tumor as determined on early postoperative MRI. Clinical trial registration no.: 2011-002527-18 (EudraCT).

Response assessment of GBM during immunotherapy by delayed contrast treatment response assessment maps.

Introduction: Assessing the treatment response of glioblastoma multiforme during immunotherapy (IT) is an open issue. Treatment response assessment maps (TRAMs) might help distinguish true tumor progression (TTP) and pseudoprogression (PsP) in this setting. Methods: We recruited 16 naïve glioblastoma patients enrolled in a phase II trial consisting of the Stupp protocol (a standardized treatment for glioblastoma involving combined radiotherapy and chemotherapy with temozolomide, followed by adjuvant temozolomide) plus IT with dendritic cells. Patients were followed up till progression or death; seven underwent a second surgery for suspected progression. Clinical, immunological, and MRI data were collected from all patients and histology in case of second surgery. Patients were classified as responders (progression-free survival, PFS > 12 months), and non-responders (PFS ≤ 12), HIGH-NK (natural killer cells, i.e., immunological responders), and LOW-NK (immunological non-responders) based on immune cell counts in peripheral blood. TRAMs differentiate contrast-enhancing lesions with different washout dynamics into hypothesized tumoral (conventionally blue-colored) vs. treatment-related (red-colored). Results: Using receiver operating characteristic (ROC) curves, a threshold of -0.066 in VBlue/VCE (volume of the blue portion of tumoral area/volume of contrast enhancement) variation between values obtained in the MRI performed before PsP/TTP and at TTP/PSP allowed to discriminate TTP from PsP with a sensitivity of 71.4% and a specificity of 100%. Among HIGH-NK patients, at month 6 there was a significant reduction compared to baseline and month 2 in median "blue" volumes. Discussion: In conclusion, in our pilot study TRAMs support the discrimination between tumoral and treatment-related enhancing features in immunological responders vs. non-responders, the distinction between PsP and TTP, and might provide surrogate markers of immunological response.

Clinicopathological and molecular landscape of 5-year IDH-wild-type glioblastoma survivors: A multicentric retrospective study.

Five-year glioblastoma (GBM) survivors (LTS) are the minority of the isocitrate dehydrogenase (IDH)-wild-type GBM patients, and their molecular fingerprint is still largely unexplored. This multicenter retrospective study analyzed a large LTS-GBM cohort from nine Italian institutions and molecularly characterized a subgroup of patients by mutation, DNA methylation (DNAm) and copy number variation (CNV) profiling, comparing it to standard survival GBM. Mutation scan allowed the identification of pathogenic variants in most cases, showing a similar mutational spectrum in both groups, and highlighted TP53 as the most commonly mutated gene in the LTS group. We confirmed DNAm as a valuable tool for GBM classification with a diagnostic refinement by using brain tumor classifier v12.5. LTS were more heterogeneous with more cases classified as diffuse pediatric high-grade glioma subtypes and having peculiar CNVs. We observed a global higher methylation in CpG islands and in gene promoters of LTS with methylation levels of distinct gene promoters correlating with prognosis.

Fluorescein-guided surgery for grade IV gliomas with a dedicated filter on the surgical microscope: preliminary results in 12 cases.

BACKGROUND: Fluorescein is widely used as a fluorescent tracer for many applications. Its capability to accumulate in cerebral areas with blood-brain barrier damage makes it an ideal dye for intraoperative visualization of malignant gliomas (MG). We report our preliminary experience in fluorescein-guided removal of grade IV gliomas using a dedicated filter on the surgical microscope. METHODS: In September 2011 we started a prospective phase II trial (FLUOGLIO) to evaluate the safety and obtain initial indications about the efficacy of fluorescein-guided surgery for MG. Patients with suspected MG amenable to complete resection of contrast-enhancing areas were eligible to participate in this study. This report is based on a preliminary analysis of the results of 12 patients with grade IV gliomas out of 15 consecutive cases (age range 48-72 years) enrolled since September 2011. Fluorescein was injected intravenously (i.v.) after intubation (5-10 mg/kg). The tumor was removed using a microsurgical technique and fluorescence visualization by BLU 400 or YELLOW 560 filters on a Pentero microscope (Carl Zeiss, Germany). The study was approved by our ethics committee and registered on the European Regulatory Authorities website (EudraCT no. 2011-002527-18). RESULTS: Histological analysis confirmed grade IV gliomas in 12/15 cases. Median preoperative tumor volume was 33.15 cm(3) (9.6-87.8 cm(3)). No adverse reaction related to the administration of fluorescein was registered. Contrast-enhanced tumor was completely removed in 75 % of the patients. CONCLUSION: This preliminary analysis suggested that the use of intravenous fluorescein during surgery on grade IV gliomas is safe and allows a high rate of complete resection of contrast-enhanced tumor at the early postoperative MRI.

Case report: Multiple brain intravascular papillary endothelial hyperplasia: incidence, diagnostic challenges, and management approach.

Multiple hemorrhagic brain lesions are mainly diagnosed based on clinico-radiological features integrated with histological data. Intravascular papillary endothelial hyperplasia (IPEH), or Masson's tumor, is a very rare entity, particularly when localized in the brain. In this study, we describe a case of multiple recurrent brain IPEHs and provide details on the diagnostic phase, therapeutic approaches, and related challenges. A 55-year-old woman presented with a relapsing neurological deficit. Brain magnetic resonance imaging (MRI) revealed a hemorrhagic right frontal-parietal lesion. When new neurological symptoms occurred, subsequent MRI scans detected more bleeding cerebral lesions. She underwent a series of single hemorrhagic lesion debulking. For any samples that underwent histopathological examination, the first results were not informative; the second and the third results revealed hemangioendothelioma (HE); and the fourth results led to the IPEH diagnosis. Interferon alpha (IFN-α) and subsequently sirolimus were prescribed. Both were well tolerated. Clinical and radiological features remained stable 43 months after starting sirolimus therapy and 132 months after the first diagnosis. To date, 45 cases of intracranial IPEH have been reported, mostly as single lesions without parenchymal location. They are usually treated by surgery and sometimes by radiotherapy upon recurrence. Our case is notable for two main reasons: because of the consecutive recurrent multifocal exclusively cerebral lesions and the therapeutic approach we used. Based on multifocal brain recurrence and good performance, we propose pharmacological therapy, including IFN-α and sirolimus, to stabilize IPEH.

FABP4 is a candidate marker of cerebellar liponeurocytomas.

Cerebellar liponeurocytoma (cLPN) is a very rare central nervous system (CNS) tumour recently recognized as a clinical and pathological entity distinct from medulloblastoma (MB), and included in the WHO classification of CNS tumours under the heading "glioneuronal tumours". cLPN typically develop in adult age and have a favourable prognosis compared with MB. In this work, we reviewed the clinical and neuroradiological data of two novel cases of adult cLPN diagnosed at our institution; one patient developed distant metastases. We tried to identify novel molecular markers for this malignancy. We found that the transcription factor NEUROG1 (but not ATOH1) is expressed in cLPN, unlike normal adult cerebellum, and that fatty acid binding protein 4 (FABP4), typically found in adipocytes, is significantly overexpressed compared with both normal adult cerebellum and human MB. These findings suggest cLPN occur as a result of transformation of cerebellar progenitors, which are distinct from cerebellar granule progenitors, and aberrantly differentiate into adipocyte-like tumour cells. They also suggest that analysis of FABP4 expression is of help to differentiate cLPN from MB.

Central nervous system lymphoma occurring in a patient with neurofibromatosis type 1 (von Recklinghausen disease).

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder, which confers an increased risk of a wide range of cancers, and malignant tumors are the most common cause of death in individuals with NF1. Although in children with NF1, the most common neoplasms are optic nerve gliomas and brain tumors, an elevated risk of myeloid leukemia and an increased relative risk of acute lymphoblastic leukemia and non-Hodgkin lymphoma were reported. In adults with NF1, the relative risk of brain tumor is 100 times higher than in the general population. Cases of malignant lymphoma occurring in NF1 adult patients have been reported. However, the association between NF1 and lymphoproliferative diseases is still debated. We report a case of CNS primitive lymphoma in an adult patient who resulted positive for NF1 at genetic testing. At present, only one case of CNS lymphoma in an adult patient displaying clinical criteria for NF1 diagnosis has been reported.