Eye movement abnormalities in neurodegenerative langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) is a rare inflammatory myeloid neoplasm characterized by proliferation of tumor histiocytes that involves multiple organs including central nervous system. The physiopathologic process underlying degenerative neuro-LCH (i.e., DN-LCH) remains imperfectly settled. Since the main clinical features of DN-LCH are cerebellar ataxia and dysexecutive syndrome, eye movements might be disrupted and may help in disease diagnosis and monitoring. We retrospectively analyzed the medical records of twenty DN-LCH patients investigated using eye movement recording (EMR) in our hospital between 2015 and 2018. DN-LCH patients exhibited (i) abnormal gain in visually guided saccades including hypermetric saccades and excessive gain variability -45.0%-, (ii) increased mean antisaccade error rates -66.7%-, (iii) altered smooth pursuit -50.0%-, and (iv) excessive number of square wave jerks-25%- and gaze-evoked nystagmus. Our study suggests that DN-LCH patients present a peculiar pattern of eye movement impairments supporting cerebellar and prefrontal dysfunctions. As a non-invasive method, EMR could therefore be a useful tool for quantitative monitoring of DN-LCH patients. Further studies are warranted to support our findings.

SARS-CoV-2 infection in patients with primary central nervous system lymphoma.

BACKGROUND: Cancer patients may be at higher risk for severe coronavirus infectious disease-19 (COVID-19); however, the outcome of Primary Central Nervous System Lymphoma (PCNSL) patients with SARS-CoV-2 infection has not been described yet. METHODS: We conducted a retrospective study within the Lymphomes Oculo-Cérébraux national network (LOC) to assess the clinical characteristics and outcome of SARS-CoV-2 infection in PCNSL patients (positive real-time polymerase chain reaction of nasopharyngeal swab or evocative lung computed tomography scan). We compared clinical characteristics between patients with severe (death and/or intensive care unit admission) and mild disease. RESULTS: Between March and May 2020, 13 PCNSL patients were diagnosed with SARS-CoV-2 infection, 11 (85%) of whom were undergoing chemotherapy at the time of infection. The mortality rate was 23% (3/13), and two additional patients (15%) required mechanical ventilation. Two patients (15%) had no COVID-19 symptoms. History of diabetes mellitus was more common in severe patients (3/5 vs 0/8, p = 0.03). Two patients recovered from COVID-19 after mechanical ventilation during more than two weeks and resumed chemotherapy. In all, chemotherapy was resumed after COVID-19 recovery in nine patients (69%) after a median delay of 16 days (range 3-32), none of whom developed unusual chemotherapy complication nor SARS-Cov2 reactivation. CONCLUSION: This preliminary analysis suggests that, while being at higher risk be for severe illness, PCNSL patients with COVID-19 might be treated maximally especially if they achieved oncological response at the time of SARS-CoV-2 infection. Chemotherapy might be resumed without prolonged delay in PCNSL patients with COVID-19.

Management and outcome of primary CNS lymphoma in the modern era: An LOC network study.

OBJECTIVE: Real-life studies on patients with primary CNS lymphoma (PCNSL) are scarce. Our objective was to analyze, in a nationwide population-based study, the current medical practice in the management of PCNSL. METHODS: The French oculo-cerebral lymphoma network (LOC) database prospectively records all newly diagnosed PCNSL cases from 32 French centers. Data of patients diagnosed between 2011 and 2016 were retrospectively analyzed. RESULTS: We identified 1,002 immunocompetent patients (43% aged >70 years, median Karnofsky Performance Status [KPS] 60). First-line treatment was high-dose methotrexate-based chemotherapy in 92% of cases, with an increasing use of rituximab over time (66%). Patients <60 years of age received consolidation treatment in 77% of cases, consisting of whole-brain radiotherapy (WBRT) (54%) or high-dose chemotherapy with autologous stem cell transplantation (HCT-ASCT) (23%). Among patients >60 years of age, WBRT and HCT-ASCT consolidation were administered in only 9% and 2%, respectively. The complete response rate to initial chemotherapy was 50%. Median progression-free survival was 10.5 months. For relapse, second-line chemotherapy, HCT-ASCT, WBRT, and palliative care were offered to 55%, 17%, 10%, and 18% of patients, respectively. The median, 2-year, and 5-year overall survival was 25.3 months, 51%, and 38%, respectively (<60 years: not reached [NR], 70%, and 61%; >60 years: 15.4 months, 44%, and 28%). Age, KPS, sex, and response to induction CT were independent prognostic factors in multivariate analysis. CONCLUSIONS: Our study confirms the increasing proportion of elderly within the PCNSL population and shows comparable outcome in this population-based study with those reported by clinical trials, reflecting a notable application of recent PCNSL advances in treatment.

Molecular Profiling Reclassifies Adult Astroblastoma into Known and Clinically Distinct Tumor Entities with Frequent Mitogen-Activated Protein Kinase Pathway Alterations.

BACKGROUND: Astroblastoma (ABM) is a rare glial brain tumor. Recurrent meningioma 1 (MN1) alterations have been recently identified in most pediatric cases. Adolescent and adult cases, however, remain molecularly poorly defined. MATERIALS AND METHODS: We performed clinical and molecular characterization of a retrospective cohort of 14 adult and 1 adolescent ABM. RESULTS: Strikingly, we found that MN1 fusions are a rare event in this age group (1/15). Using methylation profiling and targeted sequencing, most cases were reclassified as either pleomorphic xanthoastrocytomas (PXA)-like or high-grade glioma (HGG)-like. PXA-like ABM show BRAF mutation (6/7 with V600E mutation and 1/7 with G466E mutation) and CD34 expression. Conversely, HGG-like ABM harbored specific alterations of diffuse midline glioma (2/5) or glioblastoma (GBM; 3/5). These latter patients showed an unfavorable clinical course with significantly shorter overall survival (p = .021). Mitogen-activated protein kinase pathway alterations (including FGFR fusion, BRAF and NF1 mutations) were present in 10 of 15 patients and overrepresented in the HGG-like group (3/5) compared with previously reported prevalence of these alterations in GBM and diffuse midline glioma. CONCLUSION: We suggest that gliomas with astroblastic features include a variety of molecularly sharply defined entities. Adult ABM harboring molecular features of PXA and HGG should be reclassified. Central nervous system high-grade neuroepithelial tumors with MN1 alterations and histology of ABM appear to be uncommon in adults. Astroblastic morphology in adults should thus prompt thorough molecular investigation aiming at a clear histomolecular diagnosis and identifying actionable drug targets, especially in the mitogen-activated protein kinase pathway. IMPLICATIONS FOR PRACTICE: Astroblastoma (ABM) remains a poorly defined and controversial entity. Although meningioma 1 alterations seem to define a large subset of pediatric cases, adult cases remain molecularly poorly defined. This comprehensive molecular characterization of 1 adolescent and 14 adult ABM revealed that adult ABM histology comprises several molecularly defined entities, which explains clinical diversity and identifies actionable targets. Namely, pleomorphic xanthoastrocytoma-like ABM cases show a favorable prognosis whereas high-grade glioma (glioblastoma and diffuse midline gliome)-like ABM show significantly worse clinical courses. These results call for in-depth molecular analysis of adult gliomas with astroblastic features for diagnostic and therapeutic purposes.

Radiotherapy or Autologous Stem-Cell Transplantation for Primary CNS Lymphoma in Patients 60 Years of Age and Younger: Results of the Intergroup ANOCEF-GOELAMS Randomized Phase II PRECIS Study.

PURPOSE: To determine the efficacy and toxicity of chemoimmunotherapy followed by either whole-brain radiotherapy (WBRT) or intensive chemotherapy and autologous stem-cell transplantation (ASCT) as a first-line treatment of primary CNS lymphoma (PCNSL). PATIENTS AND METHODS: Immunocompetent patients (18 to 60 years of age) with untreated PCNSL were randomly assigned to receive WBRT or ASCT as consolidation treatment after induction chemotherapy consisting of two cycles of R-MBVP (rituximab 375 mg/m2 day (D) 1, methotrexate 3 g/m2 D1; D15, VP16 100 mg/m2 D2, BCNU 100 mg/m2 D3, prednisone 60 mg/kg/d D1-D5) followed by two cycles of R-AraC (rituximab 375 mg/m2 D1, cytarabine 3 g/m2 D1 to D2). Intensive chemotherapy consisted of thiotepa (250 mg/m2/d D9; D8; D7), busulfan (8 mg/kg D6 through D4), and cyclophosphamide (60 mg/kg/d D3; D2). WBRT delivered 40 Gy (2 Gy/fraction). The primary end point was 2-year progression-free survival. Cognitive outcome was the main secondary end point. Analysis was intention to treat in a noncomparative phase II trial. RESULTS: Between October 2008 and February 2014, 140 patients were recruited from 23 French centers. Both WBRT and ASCT met the predetermined threshold (among the first 38 patients in each group, at least 24 patients were alive and disease free at 2 years). The 2-year progression-free survival rates were 63% (95% CI, 49% to 81%) and 87% (95% CI, 77% to 98%) in the WBRT and ASCT arms, respectively. Toxicity deaths were recorded in one and five patients after WBRT and ASCT, respectively. Cognitive impairment was observed after WBRT, whereas cognitive functions were preserved or improved after ASCT. CONCLUSION: WBRT and ASCT are effective consolidation treatments for patients with PCNSL who are 60 years of age and younger. The efficacy end points tended to favor the ASCT arm. The specific risk of each procedure should be considered.

Incidence and risk factors for clinical neurodegenerative Langerhans cell histiocytosis: a longitudinal cohort study.

Neurodegenerative (ND) complications in Langerhans cell histiocytosis (LCH) are a late-onset but dramatic sequelae for which incidence and risk factors are not well defined. Based on a national prospective registry of paediatric LCH patients, we determined the incidence rate of clinical ND LCH (cND-LCH) and analysed risk factors, taking into account disease extent and molecular characteristics. Among 1897 LCH patients, 36 (1·9%) were diagnosed with a cND-LCH. The 10-year cumulative incidence of cND-LCH was 4·1%. cND-LCH typically affected patients previously treated for a multisystem, risk organ-negative LCH, represented in 69·4% of cND-LCH cases. Pituitary gland, skin and base skull/orbit bone lesions were more frequent (P < 0·001) in cND-LCH patients compared to those without cND-LCH (respectively 86·1% vs. 12·2%, 75·0% vs. 34·2%, and 63·9% vs. 28·4%). The 'cND susceptible patients' (n = 671) i.e., children who had experienced LCH disease with pituitary or skull base or orbit bone involvement, had a 10-year cND risk of 7·8% vs. 0% for patients who did not meet these criteria. Finally, BRAFV600E status added important information among these cND susceptible patients, with the 10-year cND risk of 33·1% if a BRAFV600E mutation was present compared to 2·9% if it was absent (P = 0·002).

Rituximab, methotrexate, procarbazine, vincristine and intensified cytarabine consolidation for primary central nervous system lymphoma (PCNSL) in the elderly: a LOC network study.

Primary CNS lymphoma (PCNSL) is chemosensitive to high-dose methotrexate-based chemotherapy. However, responses in the elderly are short-lasting and outcome is poor. Given that radiotherapy and intensive chemotherapy expose elderly to severe toxicities, alternative consolidation approaches need to be evaluated. In this multicenter study, we retrospectively analyzed consecutive patients with newly-diagnosed PCNSL, aged >60, treated with a (R)-MPV-AAA regimen. The regimen consisted of three 28-day cycles of methotrexate (3.5 g/m2 D1, D15), procarbazine, vincristine, followed by three 28-day cycles of cytarabine consolidation (3 g/m2 D1-2). Addition of rituximab (375 mg/m2 D1) was optional. The results were compared with the historical MPV-A regimen. Ninety patients received the (R)-MPV-AAA regimen with (n = 39) or without (n = 51) rituximab. Median age was 68 and median KPS 60. 55% of patients achieved a complete response, 8% a partial response and 37% progressed. The median PFS was 10 months, the median OS 28.1 months. Toxicity was mainly hematological, with 54 and 51% of grade III-IV neutropenia and thrombopenia. The response rate was higher in patients receiving rituximab (77 vs. 53%; p = 0.03), whereas no difference was observed in terms of PFS or OS. When comparing the results to the historical MPV-A, there was no difference in terms of response rate, PFS or OS, but a higher rate of hematotoxicity. This study suggests that extending cytarabine consolidation after methotrexate-based chemotherapy does not improve the MPV-A efficacy but increases toxicity in the elderly. The addition of rituximab may improve the response rate, but its impact on final outcome remains unclear.

Patterns of response and relapse in primary CNS lymphomas after first-line chemotherapy: imaging analysis of the ANOCEF-GOELAMS prospective randomized trial.

Background: Our aim was to review MRI characteristics of patients with primary CNS lymphoma (PCNSL) enrolled in a randomized phase II trial and to evaluate their potential prognostic value and patterns of relapse, including T2 fluid attenuated inversion recovery (FLAIR) MRI abnormalities. Methods: Neuroimaging findings in 85 patients with PCNSL enrolled in a prospective trial were reviewed blinded to outcomes. MRI characteristics and responses according to International PCNSL Collaborative Group (IPCG) criteria were correlated with progression-free survival (PFS) and overall survival (OS). Results: Multivariate analysis showed that objective response at 2 months (P < .001) and at end of treatment (P = .015) were predictors of prolonged OS. Infratentorial location (P = .008) and large (>11.4 cm3) enhancing tumor volume (P = .006) were associated with poor OS and PFS, respectively. Ratio of change in product of largest diameters at early MRI evaluation but not timing of complete response achievement (early vs delayed) was prognostic for OS. Sixty-nine patients relapsed. Relapse in the brain (n = 52) involved an initial enhancing site, a different site, or both in 46%, 40%, and 14% of patients, respectively. At baseline, non-enhancing T2-FLAIR hypersignal lesions distant from the enhancing tumor site were detected in 18 patients. These lesions markedly decreased (>50%) in 16 patients after chemotherapy, supporting their neoplastic nature. Of these patients, 10/18 relapsed, half (n = 5) in the initially non-enhancing T2-FLAIR lesions. Conclusions: Baseline tumor size and infratentorial localization are of prognostic value in PCNSL. Our findings provide evidence that non-enhancing FLAIR abnormalities may add to overall tumor burden, suggesting that response criteria should be refined to incorporate evaluation of T2-weighted/FLAIR sequences.

[Neuro-Langerhans cell histiocytosis]. / Neurohistiocytose langerhansienne.

Langerhans cell histiocytosis (LCH) is a rare multisystemic disease. LCH is characterized by proliferation of myeloid progenitors with altered differentiation program and similar phenotypic features to epidermal dendritic cells termed Langerhans cell. LCH cells express CD1a+ and langerin and exhibit BRAF V600E mutation in ∼50% of cases. Neurological involvement or neuro-LCH is observed in 5 to 10% of cases. Three subtypes of neuro-LCH are individualized. The tumor type, accounting for 45% of neuro-LCH, affect mainly young adults. Tumor neuro-LCH is characterized by space occupying lesion(s) with contrast enhancement on MRI. Clinical symptoms are due to tumor brain location(s). Pathological examination of tumor neuro-LCH lesions reveals typical features of LCH. Treatment relies on surgical resection with/without chemotherapy. Degenerative neuro-LCH, accounting for 45% of cases, is usually revealed, mostly in children, by: (i) a cerebellar syndrome, (ii) a pyramidal syndrome, (iii) a pseubulbar palsy, and/or (iv) cognitive disorders. On MRI, several signs may coexist: (i) cortex atrophy, (ii) white matter T2 hyperintensities, and (iii) deep gray matter T1 hyperintensities. Pathological analysis of degenerative neuro-LCH lesions have been rarely performed and have never detected CD1a+ histiocytes but unspecific lesions (i.e. gliosis, neuronal loss and/or demyelination). Treatment of degenerative neuro-LCH patients is poorly standardized and poorly efficient. Functional rehabilitation and socio-educational care of these young patients are crucial. The mixed subtype of neuro-LCH combines clinico-radio-pathological characteristics of the first two first forms in the same patient, and represents 10% of neuro-HL. Neuro-HL, therefore, includes three very distinct entities with epidemiological, clinical, radiological and histological specific features requiring specific medical management.

Integrated multi-omics analysis of oligodendroglial tumours identifies three subgroups of 1p/19q co-deleted gliomas.

Oligodendroglial tumours (OT) are a heterogeneous group of gliomas. Three molecular subgroups are currently distinguished on the basis of the IDH mutation and 1p/19q co-deletion. Here we present an integrated analysis of the transcriptome, genome and methylome of 156 OT. Not only does our multi-omics classification match the current classification but also reveals three subgroups within 1p/19q co-deleted tumours, associated with specific expression patterns of nervous system cell types: oligodendrocyte, oligodendrocyte precursor cell (OPC) and neuronal lineage. We confirm the validity of these three subgroups using public datasets. Importantly, the OPC-like group is associated with more aggressive clinical and molecular patterns, including MYC activation. We show that the MYC activation occurs through various alterations, including MYC genomic gain, MAX genomic loss, MYC hypomethylation and microRNA-34b/c down-regulation. In the lower grade glioma TCGA dataset, the OPC-like group is associated with a poorer outcome independently of histological grade. Our study reveals previously unrecognized heterogeneity among 1p/19q co-deleted tumours.

Temozolomide after radiotherapy in recurrent "low grade" diffuse brainstem glioma in adults.

Diffuse brainstem glioma is a rare disease in adults. Radiotherapy (RT) is usually considered to be the standard treatment. However, the role of chemotherapy in treating relapses after RT is unclear, and this study aimed to assess the use of temozolomide (TMZ) in this situation. We conducted a retrospective analysis of patients from our database with "low grade" adult diffuse infiltrating brainstem glioma who received TMZ at relapse after failing RT. The patients were diagnosed by histology or MRI criteria compatible with a low-grade glioma. The tumors were localized in the pons, medulla oblongata or midbrain, excluding supratentorial or infratentorial tumors that had infiltrated the brainstem secondarily. The patients' clinical and radiological responses were assessed, and their progression free survival (PFS) and overall survival (OS) time were estimated. Fifteen adult patients (median age 34 years) fulfilled the inclusion criteria. Histological analysis was available in 5 cases and showed grade II oligodendroglioma (2 cases), grade II oligoastrocytoma (2 cases), and grade II astrocytoma (1 case). Ten patients were selected by MRI criteria only. All patients received RT as initial treatment and had a median PFS of 34.2 months (95 % CI 24.1-44.2). The median KPS at the time of relapse was 80. TMZ was administered orally at 150-200 mg/m(2) for 5 days, every 28 days. Clinical improvement after TMZ was observed in 9 cases (60 %), whereas radiological assessment detected responses in 6/15 cases, including 4 partial and 2 minor responses. The estimated median PFS after TMZ was 9.5 months (95 % CI 7.9-11), and the median OS was 14.4 months (95 % CI 10.5-18.2). Grade 3 thrombopenia was observed in 26 % of cases. TMZ could be useful after RT failure in adult patients with recurrent diffuse "low grade" brainstem glioma.

Fibrous dysplasia and McCune-Albright syndrome: imaging for positive and differential diagnoses, prognosis, and follow-up guidelines.

PURPOSE: The radiologist plays a critical role at all steps of the management of patients with fibrous dysplasia (FD) and McCune-Albright syndrome (MAS). The development of a standardized approach to the management of FD/MAS is crucial given the low incidence and multiple clinical presentations of these conditions. Our aim was to develop recommendations for bone imaging in FD/MAS management. MATERIALS AND METHODS: The establishment of National Reference Centers in France as part of a Health Ministry program for orphan diseases has triggered the development of recommendations for the clinical management of FD/MAS. We used a well-established robust methodological approach involving an extensive literature review by a multidisciplinary working group (20 healthcare professionals) and scoring by a peer-review group (20 healthcare professionals different from the 20 previous ones). There were four phases: a systematic literature review, drafting of initial recommendations, peer-review of this initial draft, and drafting of the final recommendations. RESULTS: Fifty-seven specific recommendations are provided as key points for the diagnosis, prognosis, and follow-up of patients with FD/MAS. Issues of special interest are highlighted in the discussion, and areas in which future research is needed are identified. CONCLUSION: We believe the dissemination of these recommendations within the radiology community may facilitate communication between radiologists and other healthcare providers, thereby substantially improving the management of patients with these rare but potentially disabling conditions.

The cognitive spectrum in neurodegenerative Langerhans cell histiocytosis.

Clinical spectrum of cognitive troubles complicating neurodegenerative Langerhans cell histiocytosis (ND-LCH) is poorly known. The aim of this study is to evaluate cognitive functions in ND-LCH. The cognitive functions of a series of eight adult patients (7 males and 1 female; mean age 26 years IQ 25-75; range 20-33) suffering from clinical and/or radiological ND-LCH were evaluated using the following tests: (1) forward/backward digit and spatial span tasks of the WAIS-R scale and the Corsi block task, (2) the French version of the free and cued selective reminding test, (3) verbal fluency tests, (4) the Frontal Assessment Battery (FAB), (5) backward measurement of the verbal and visuospatial memories of the WAIS-R scale, (6) the Rey complex figure test, (7) the trail making tests A and B, (8) digit symbol and symbol search of the WAIS-IV scale, and (9) the Stroop test. Episodic (i.e. autobiographical or personal) memory free recall, categorical verbal fluency, phonological verbal fluency, visuospatial processing skills, attention, speed of processing, and sensitivity to interference were impaired in ND-LCH patients. In contrast, verbal and visuospatial short-term memories (i.e. immediate memories or forward span tasks) were preserved in all patients. Adult ND-LCH patients suffer from a severe but dissociated dysexecutive syndrome, mostly affecting executive strategies and relatively sparing short-term memory. Our study supports the need of assessing executive functions using comprehensive cognitive evaluation in ND-LCH patients for early diagnosis.

Contrast enhancement in 1p/19q-codeleted anaplastic oligodendrogliomas is associated with 9p loss, genomic instability, and angiogenic gene expression.

BACKGROUND: The aim of this study was to correlate MRI features and molecular characteristics in anaplastic oligodendrogliomas (AOs). METHODS: The MRI characteristics of 50 AO patients enrolled in the French national network for high-grade oligodendroglial tumors were analyzed. The genomic profiles and IDH mutational statuses were assessed using high-resolution single-nucleotide polymorphism arrays and direct sequencing, respectively. The gene expression profiles of 25 1p/19q-codeleted AOs were studied on Affymetrix expression arrays. RESULTS: Most of the cases were frontal lobe contrast-enhanced tumors (52%), but the radiological presentations of these cases were heterogeneous, ranging from low-grade glioma-like aspects (26%) to glioblastoma-like aspects (22%). The 1p/19q codeletion (n = 39) was associated with locations in the frontal lobe (P = .001), with heterogeneous intratumoral signal intensities (P = .003) and with no or nonmeasurable contrast enhancements (P = .01). The IDH wild-type AOs (n = 7) more frequently displayed ringlike contrast enhancements (P = .03) and were more frequently located outside of the frontal lobe (P = .01). However, no specific imaging pattern could be identified for the 1p/19q-codeleted AO or the IDH-mutated AO. Within the 1p/19q-codeleted AO, the contrast enhancement was associated with larger tumor volumes (P = .001), chromosome 9p loss and CDKN2A loss (P = .006), genomic instability (P = .03), and angiogenesis-related gene expression (P < .001), particularly for vascular endothelial growth factor A and angiopoietin 2. CONCLUSION: In AOs, the 1p/19q codeletion and the IDH mutation are associated with preferential (but not with specific) imaging characteristics. Within 1p/19q-codeleted AO, imaging heterogeneity is related to additional molecular alterations, especially chromosome 9p loss, which is associated with contrast enhancement and larger tumor volume.

Adult brainstem gliomas.

Brainstem gliomas are uncommon in adults and account for only 1%-2% of intracranial gliomas. They represent a heterogeneous group of tumors that differ from those found in their pediatric counterparts. In adults, a low-grade phenotype predominates, which is a feature that likely explains their better prognosis compared to that in children. Because biopsies are rarely performed, classifications based on the radiological aspect of magnetic resonance imaging results have been proposed to establish treatment strategies and to determine outcomes: (a) diffuse intrinsic low-grade, (b) enhancing malignant glioma, (c) focal tectal gliomas, and (d) exophytic gliomas. Despite significant advances in neuroradiology techniques, a purely radiological classification remains imperfect in the absence of a histological diagnosis. Whereas a biopsy may often be reasonably avoided in the diffuse nonenhancing forms, obtaining histological proof seems necessary in many contrast-enhanced brainstem lesions because of the wide variety of differential diagnoses in adults. Conventional radiotherapy is the standard treatment for diffuse intrinsic low-grade brainstem gliomas in adults (the median survival is 5 years). In malignant brainstem gliomas, radiotherapy is the standard treatment. However, the possible benefit of combined radiotherapy and chemotherapy (temozolomide or other agents) has not been thoroughly evaluated in adults. The role of anti-angiogenic therapies in brainstem gliomas remains to be defined. A better understanding of the biology of these tumors is of primary importance for identifying homogeneous subgroups and for improving therapy options and outcomes.

Efficacy of vinblastine in central nervous system Langerhans cell histiocytosis: a nationwide retrospective study.

BACKGROUND: Vinblastine (VBL) is the standard treatment for systemic Langerhans cell histiocytosis (LCH), but little is known about its efficacy in central nervous system (CNS) mass lesions. METHODS: A retrospective chart review was conducted. Twenty patients from the French LCH Study Group register met the inclusion criteria. In brief, they had CNS mass lesions, had been treated with VBL, and were evaluable for radiologic response. RESULTS: The median age at diagnosis of LCH was 11.5 years (range: 1-50). Intravenous VBL 6 mg/m2 was given in a 6-week induction treatment, followed by a maintenance treatment. The median total duration was 12 months (range: 3-30). Eleven patients received steroids concomitantly. Fifteen patients achieved an objective response; five had a complete response (CR: 25%), ten had a partial response (PR: 50%), four had stable disease (SD: 20%) and one patient progressed (PD: 5%). Of interest, four out of the six patients who received VBL without concomitant steroids achieved an objective response. With a median follow-up of 6.8 years, the 5-year event-free and overall survival was 61% and 84%, respectively. VBL was well-tolerated and there were no patient withdrawals due to adverse events. CONCLUSION: VBL, with or without steroids, could potentially be a useful therapeutic option in LCH with CNS mass lesions, especially for those with inoperable lesions or multiple lesions. Prospective clinical trials are warranted for the evaluation of VBL in this indication.

18F-FDG PET in neurodegenerative Langerhans cell histiocytosis : results and potential interest for an early diagnosis of the disease.

INTRODUCTION: The so called "neurodegenerative Langerhans cell histiocytosis" (ND-LCH) is a rare and severe complication of LCH presenting as a progressive cerebellar ataxia associated with pyramidal tract signs, and cognitive impairment. MRI is the gold standard to investigate CNS lesions of ND-LCH but little is known about functional changes observed in this disease. OBJECTIVES: To search for CNS metabolic changes in NDLCH. METHODS: Seven patients suffering from ND-LCH were investigated by 18F-FDG PET in this prospective study and compared with 21 healthy controls. RESULTS: ND-LCH patients demonstrated recurrent abnormalities including bilateral hypometabolism in the cerebellum, the basal ganglia (caudate nuclei), frontal cortex and, bilateral, a relatively increased metabolism in the amygdalae (p < 0.001). Functional changes in these anatomical regions may be detected in the absence of any apparent lesion on MRI. CONCLUSIONS: ND-LCH demonstrates a recurrent 18F-FDG PET metabolic signature. Our results suggest that 18F-FDG PET might be a useful tool for an early diagnosis of ND-LCH before neuroradiologic abnormalities appear.