Meningeal SWI/SNF related, matrix-associated, actin-dependent regulator of chromatin, subfamily B member 1 (SMARCB1)-deficient tumours: an emerging group of meningeal tumours.

AIMS: Bi-allelic inactivation of SWI/SNF related, matrix-associated, actin-dependent regulator of chromatin, subfamily B member 1 (SMARCB1; also known as INI1) and loss of immunohistochemical expression of SMARCB1 define the group of SMARCB1-deficient tumours. Initially highlighted in malignant rhabdoid tumours, this inactivation has subsequently been observed in several intra and extracranial tumours. To date, primary meningeal SMARCB1-deficient tumours have not been described. We report two cases of meningeal SMARCB1-deficient tumours occurring in adults. METHODS: We performed immunohistochemical analyses, comparative genomic hybridization, fluorescence in situ hybridization and targeted next-generation sequencing. RESULTS: The first meningeal tumour was a solitary mass, composed of rhabdoid, adenoid, chordoid and sarcomatoid areas. The second case presented as multiple, bilateral, supra and infratentorial nodules, was composed of fusiform and ovoid cells embedded in a myxoid stroma. Tumour cells were positive for epithelial membrane antigen (EMA), vimentin and CD34 and negative for SMARCB1 and meningothelial, melanocytic, muscular, glial markers. In the first case, one allele of SMARCB1 was completely deleted, whereas in the second case, loss of expression of SMARCB1 was observed as a consequence of a homozygous deletion of SMARCB1. CONCLUSIONS: The phenotype and genotype of these two cases did not fit diagnostically with entities already known to be SMARCB1-deficient tumours. As both tumours shared common features, they are regarded as belonging to an emerging group of primary meningeal SMARCB1-deficient tumours, not described to date. To facilitate the identification and characterization of these tumours, we recommend SMARCB1 immunohistochemistry for primary meningeal tumours which are difficult to classify, especially if immunopositive for EMA and CD34.

Patterns of care and survival of glioblastoma patients: a comparative study between 2004 and 2008 in Lyon, France.

INTRODUCTION: The treatment of glioblastomas (GBMs) has changed significantly since 2005. However, the extent to which this change has improved overall survival (OS) of patients treated outside clinical trials remains to be determined. METHODS: We compared the patterns of care and OS of all GBM patients diagnosed in 2004 (n=105) and in 2008 (n=130) in our center. RESULTS: Younger patients (aged<70 years) diagnosed in 2008 received temozolomide radiochemotherapy as the initial treatment and bevacizumab at recurrence more frequently than those diagnosed in 2004 (69% vs 26% P<10(-4) and 41% vs 3%, P<10(-4), respectively). Elderly patients (aged≥70 years) diagnosed in 2008 received an oncological treatment (radiotherapy and/or chemotherapy) more frequently than those diagnosed in 2004 (67% vs 38%, P=0.006). The patients diagnosed in 2008 had longer OS than those diagnosed in 2004 (10.5 months vs 5.3 months, P=0.001). This finding was true for both younger and elderly patients (15.3 months vs 8.9 months, P=0.02 and 6.4 months vs 3.2 months, P=0.0002, respectively) and when considering only IDH1 wild-type patients (8.9 months vs 5.3 months, P=0.004). CONCLUSION: In our center, the change in the patterns of care for GBMs between 2004 and 2008 has been associated with a significant improvement in OS.

Role of surgery, radiotherapy and chemotherapy in papillary tumors of the pineal region: a multicenter study.

Papillary tumor of the pineal region (PTPR), recently described as a distinct clinicopathological entity, can show aggressive biological behavior. The optimal therapeutic approach of PTPR has not been well defined. The role of surgery, radiotherapy, and chemotherapy in the treatment of PTPR was analyzed in a large multicenter series. In order to determine factors that influence prognosis, outcome data of a series of 44 patients with histopathologically proven PTPR were retrospectively analyzed. Of the 44 patients, 32 were still alive after a median follow-up of 63.1 months. Twelve patients experienced progressive disease, with seven undergoing two relapses and five more than two. Median overall survival (OS) was not achieved. Median progression-free survival (PFS) was 58.1 months. Only gross total resection and younger age were associated with a longer OS, radiotherapy and chemotherapy having no significant impact. PFS was not influenced by gross total resection. Radiotherapy and chemotherapy had no significant effect. This retrospective series confirms the high risk of recurrence in PTPR and emphasizes the importance of gross total resection. However, our data provide no evidence for a role of adjuvant radiotherapy or chemotherapy in the treatment of PTPR.

Utility of Ki67 immunostaining in the grading of pineal parenchymal tumours: a multicentre study.

AIMS: Pineal parenchymal tumours (PPTs) are rare neoplasms that are divided into pineocytoma (PC), pineoblastoma (PB) and PPT of intermediate differentiation (PPTID). Factors affecting the survival of patients with PPTs are morphological subtype and histological grading according to mitotic index and neurofilament immunostaining. Grading criteria to distinguish PPTIDs are difficult to define, particularly when using small specimens. The Ki67 labelling index (LI) might be helpful in distinguishing between grade II and III PPTIDs. Our study was performed to assess the predictive value of the Ki67 LI in a large cooperative series of PPTs and to evaluate whether inclusion of this data would improve and refine the World Health Organization classification. METHODS: A retrospective analysis of 33 PPTs was performed. The histological features of the tumours were reviewed and Ki67 LI scoring was evaluated by immunohistochemistry. Data were correlated with the patients' survival. RESULTS: The mean Ki67 LI was significantly different for tumour grades (0 in PC, 5.2 ± 0.4 in PPTID grade II, 11.2 ± 2.0 in PPTID grade III, 36.4 ± 6.2 in PB; P < 0.0001). However, there was no statistically significant difference in either overall or disease-free survival evaluated by the Kaplan-Meier method for patients with different grade tumours or Ki67 LI, possibly due to the different clinical management of patients in different centres. CONCLUSIONS: The Ki67 LI may be a useful additional tool for grading PPTs, more particularly in small tumour samples.

[Medulloblastomas: review]. / Les médulloblastomes: revue générale.

INTRODUCTION: The term of "medulloblastoma" refers to cerebellar tumors belonging to the family of primitive neuro-ectodermic tumors (PNET). Medulloblastomas represent 40% of cerebellar tumors, 15 to 20% of brain tumors and the first cause of malignant brain tumors in childhood. Seventy to 80% of cases are diagnosed in children versus 20 to 30% in adults. UPDATED KNOWLEDGE: Diagnosis is based on clinical and radiological exams, and proved on pathological analysis in association with molecular biology. Treatment comprises surgery, craniospinal radiotherapy except for children under five years of age and chemotherapy according to age and high-risk criteria. Medulloblastoma is a rare case of a central nervous system tumor which is radio- and chemo-sensitive. Treatment goals are, on one hand, to improve the survival rates and, on the other hand, to avoid late neurocognitive, neuroendocrine and orthopedic side effects related to radiation therapy, notably in children. The prognosis is relatively good, with a five year survival rate over 75% after complete resection of a localized tumor although sequelae may still compromise outcome. PERSPECTIVES AND CONCLUSION: Management of patients with medulloblastoma implies a multidisciplinary approach combining the contributions of neurosurgery, neuroradiology, pediatric oncology, neuro-oncology and radiotherapy teams.

Histological features and expression of enzymes implicated in melatonin synthesis in pineal parenchymal tumours and in cultured tumoural pineal cells.

Pineal parenchymal tumours (PPT) are rare neoplasms and there have been few in vitro studies. Their capacity for synthesizing and secreting melatonin has been only partially examined. We investigated the presence of messenger RNA (mRNA) encoding tryptophan hydroxylase (TPH), arylalkylamine N-acetyltransferase (AANAT), hydroxyindol-O-methyltransferase (HIOMT), three enzymes involved in melatonin synthesis, and c-myc, a tumoural marker, in 10 PPT, one papillary tumour of the pineal region (PTPR), cell cultures derived from four PPTs and from three other tumours of the pineal region, and in normal pineal gland. Moreover, protein expression of TPH was investigated in three PPT and PTPR. Quantitative real-time reverse transcriptase-polymerase chain reaction and immunohistochemistry were used and the melatonin production by tumoural cells in vitro was analysed by radioimmunoassay. We showed that all the tumoural tissues and cells contained c-myc mRNA. mRNAs encoding TPH, AANAT and HIOMT were detected in all PPT, suggesting that tumour cells can synthesize melatonin. Only PPT expressed TPH protein. Cultured cells lost expression of transcripts throughout passages even if ultrastructural study revealed the presence of characteristic organelles in these tumoural cells. Nevertheless, the basal secretion of melatonin observed in one PPT culture is in favour of a maintained melatonin production and secretion by tumoural pinealocytes, but melatonin production was not stimulated by a beta noradrenergic agonist. Moreover, PTPR never expressed mRNA encoding TPH, AANAT and HIOMT. Our results may contribute to a better understanding of the biology of PTT and PTPR and may help to the diagnosis of these rare tumours.

Expression of c-Myc, neurofibromatosis Type 2, somatostatin receptor 2 and erb-B2 in human meningiomas: relation to grades or histotypes.

Meningiomas, which originate from arachnoid cells, represent one of the largest subgroups of intracranial tumors. They are generally benign, but can progress to malignancy. The aim of our study was to determine the expression of 4 genes, c-Myc, neurofibromatosis Type 2 (NF2), somatostatin receptor isoform 2 (sst2) and erb-B2, that have been associated with tumorogenesis or, possibly, with aggressive behavior or recurrence of meningiomas. We measured levels of mRNAs coding for these genes by qRT-PCR in 51 cases and levels ofc-Myc protooncogene and sst2 protein by immunohistochemistry in 26 cases of meningiomas of various grades and histotypes. C-Myc mRNA and protein levels were not grade-related, but validated subdivision of the 36 benign meningiomas into two groups, Groups IA and IB, based on histological and clinical features (Ki-67-proliferative index, absence or presence of mitoses, rate of recurrence and incidence of perilesional edema). In addition to histopathological grading, c-Myc expression may be useful in predicting tumor recurrence in patients with low-grade meningiomas. NF2 mRNA levels and sst2 mRNA and receptor levels were not grade-related, but were histotype-related, with significantly higher levels in the meningothelial subtype than in the fibroblastic subtype. Erb-B2 mRNA levels were not grade- or histotype-related. Furthermore, the high expression of sst2 in meningothelial meningioma suggests the possibility of a different tumorigenesis process in this meningioma subtype and may open perspectives for the diagnosis and therapy of this subtype using somatostatin as an antiproliferative agent.

Pathology of tumors of the pineal region.

Tumors of the pineal region are rare and relatively few centers around the world have published substantial numbers of carefully studied cases. This review gives a historical account of our understanding of the normal pineal and the evolution of the classification of tumors and other mass lesions of the pineal region in human beings. Based on our experience over the past 30 years, a working classification is proposed and recent advances in the neuropathology of these lesions are discussed.

[Cerebral amyloid angiopathy]. / L'angiopathie amyloïde cérébrale.

Cerebral amyloid angiopathy (CAA) is characterized by deposition of cerebrovascular amyloid protein in the media of leptomeningeal vessels. (amyloid B protein, cystatin C, transthyretin, gelsolin, and prion protein). It is a cause of cerebrovascular disorders including cerebral hemorrhage, cognitive impairment and unusually transient neurological symptoms. It is the main contributing factor to cerebral hemorrhage after hypertension in the elderly. We aimed to review epidemiological, pathophysiological and clinical and MRI imaging data in CAA.

[Intracranial ependymomas in adult patients. Retrospective analysis of 121 cases from the multicentric French study]. / Ependymomes intracrâniens de l'adulte. Analyse rétrospective de 121 cas provenant de l'étude multicentrique française.

Ependymomas are rare intracranial tumors observed in adults. Prognostic factors as well as proper therapeutic management remain controversial. We report a retrospective study of 121 cases intracranial ependymomas diagnosed between 1990 and 2004 in adult patients. Mean age was 46 years with a 1/1 sex-ratio. Supratentorial and infratentorial localization was noted for 41 (33.9%) and 80 (66.1%) patients respectively. Total gross resection was achieved for 62.8% of tumors. WHO staging was grade II for 72.7% and III for 27.3%. Recurrence developed in 41 (33.9%) patients. Median follow-up was 70 months. The 5-year and 10-year overall survivals were 85 and 76% respectively; the respective progression-free survivals were 64 and 43%. At univariate analysis, age, KPS, localization, extent of surgery and histological grade were correlated with overall survival. At multivariate analysis age, location, histological grade and extent of surgery contributed most to prediction of overall survival. Concerning progression-free survival, univariate analysis found age, KPS, localization, extent of surgery, complementary treatment and histological grade to be correlated with recurrence. Multivariate analysis retained extent of surgery, histological grade and complementary treatment as the most important predictors of progression-free survival. This study demonstrated that extent of surgery and tumor grade are the two main prognostic factors in adult intracranial ependymomas with respect to overall and progression-free survival. Furthermore, our data suggest that postoperative radiotherapy significantly increases progression-free survival in patients with incompletely resected grade II tumors.

[Intracranial ependymomas in adult patients. Diagnosis and histological prognostic factors]. / Ependymomes intracrâniens de l'adulte. Diagnostic histologique et facteurs histopronostiques.

BACKGROUND: Intracranial ependymomas are rare in adults and histopathological prognostic factors are poorly determined. PURPOSE: A retrospective multicentric study was conducted in France in order to assess the prognostic value of histology. MATERIAL: Between 1990 and 2004, 216 adult patients with newly diagnosed ependymomas were treated in 19 French centers. Eligibility required institutional histopathological confirmation of an ependymoma and available clinical history and MRI features (see comparison paper). METHODS: Histological preparations and one paraffin embedded block from each patient were sent to Pr D. Figarella-Branger in Marseille. Central review by four neuropathologists (D. Figarella-Branger, A. Maues de Paula, C. Fernandez and A. Jouvet) was performed. Specimens for which all pathologists agreed with the histological diagnosis of ependymomas were included, whereas cases for which all disagree were excluded and reclassified. In the event of doubt and/or discrepancies between pathologists immunostaining was performed in order to reach a consensus diagnosis. Diagnostic of ependymomas was confirmed in 121 cases (56%). In theses cases, ependymomas were classified according to the WHO system (subtype and grade). The potential prognostic value (overall survival OS and disease free survival DFS) of the following histological parameters was examined: perivascular pseudorosettes, ependymal rosettes, hyalinized vessels, mitotic index, microvascular proliferation, necrosis, area of increased cellularity, nuclear atypia, brain invasion and Mib-1 labelling index. RESULTS: Among the 121 ependymomas, 88 were grade II (47 classic, 17 cellular, 2 papillar, 6 clear cells and 16 tanicytic) and 33 grade III. WHO grading, occurrence of microvascular proliferation, necrosis, nuclear atypia and high proliferative index were correlated with both OS and DFS. Moreover, quantification of certain parameters enabled a reproducible grading system correlated with both OS and DFS.

[Diffusion and perfusion MR imaging in cerebral lymphomas]. / IRM de diffusion-perfusion dans l'évaluation des lymphomes cérébraux.

Because of the increasing incidence of cerebral lymphoma, it is critical for patient management to recognize the MR features of this disease. We present the characteristic morphological and functional MRI features of this tumor. The findings on MRI studies, including morphological, diffusion and perfusion imaging, performed in 9 biopsy-proven cases of cerebral lymphoma with 13 lesions are presented and analyzed, and are discussed in comparison with published literature data. All patients underwent diffusion-weighted imaging with a single shot echo-planar pulse sequence. Dynamic susceptibility-contrast MRI was performed using a T2*-weighted gradient-echo echo-planar sequence after intravenous injection of chelates of gadolinium at the rate of 6 ml/s and a temporal resolution of 1 second. All cases of cerebral lymphoma appeared hypointense or isointense on T1-weighted images and in 75% of cases iso- or hypointense on T2-weighted images. All lesions enhanced except one in a patient receiving steroid therapy. On diffusion-weighted images, tumours were hyperintense with normal or decreased ADC values (0.717+/-0.152.10-3 mm2/sec, range: 0.550-1.014) and an ADC ratio tumour/normal white matter of 0.974+/-0.190 (range: 0.768-1.410). On perfusion, the signal intensity-time curve of each tumour showed a characteristic type of curve with a significant increase of the signal intensity above the baseline and a low maximum relative cerebral blood volume ratio (rCVBmax) of 1.43+/-0.64 (0.55-2.62). Due to their higher cellularity, the lack of neoangiogenesis, and the increased permeability of the blood-brain barrier related to the infiltration of blood vessels wall by lymphomatous cells, cerebral lymphoma presents characteristic diffusion and perfusion MRI features that should be useful for diagnosis and patient follow-up.

Germline SDHD mutation in paraganglioma of the spinal cord.

Hereditary paraganglioma of the head and neck is associated with germline mutations in the SDHD gene, which encodes a mitochondrial respiratory chain protein. Paragangliomas of the central nervous system are very rare, occur almost exclusively in the cauda equina of the spinal cord and are considered non-familial. In the present study, we screened 22 apparently sporadic paragangliomas of the cauda equina for SDHD mutations. One spinal paraganglioma and similar cerebellar tumours that developed 22 years later in the same patient contained a missense mutation at codon 12 (GGT-->AGT, Gly-->Ser) and a silent mutation at codon 68 (AGC-->AGT, Ser-->Ser). There was no family history of paragangliomas but DNA from white blood cells of this patient showed the same sequence alterations, indicating the presence of a germline mutation. All other cases of spinal paraganglioma had the wild-type SDHD sequence, except one case with a silent mutation at codon 68 (AGC-->AGT, Ser-->Ser). This is the first observation indicating that inherited SDHD mutations may occasionally cause the development of paragangliomas in the central nervous system.

Temozolomide in malignant gliomas of childhood: a United Kingdom Children's Cancer Study Group and French Society for Pediatric Oncology Intergroup Study.

PURPOSE: To determine the response rate of the malignant gliomas of childhood to an oral, daily schedule of temozolomide. PATIENTS AND METHODS: A multicenter, phase II evaluation of an oral, daily schedule of temozolomide (200 mg/m(2) on 5 consecutive days) was undertaken in children with relapsed or progressive, biopsy-proven, high-grade glioma (arm A) and progressive, diffuse, intrinsic brainstem glioma (arm B). Evidence of activity was defined by radiologic evidence of a sustained reduction in tumor size on serial magnetic resonance imaging scans. RESULTS: Fifty-five patients were recruited (34 to arm A and 21 to arm B) and received 215 cycles of chemotherapy. Grade 3/4 thrombocytopenia was the most frequent toxic event (7% of cycles). Prolonged myelosuppression resulted in significant treatment delays and dose reductions (17% and 22% of cycles, respectively). Two toxic deaths were documented and were related to myelosuppression and sepsis in one patient and pneumonia in a second. The overall (best) response rate was 12% for arm A (95% confidence interval [CI], 3 to 28 in the study cohort, and 2 to 31 for eligible patients) and 5% and 6%, respectively, for arm B (95% CI, 0 to 26 in the study cohort, and 0 to 27 for eligible patients). Stabilization of disease was also documented and was most noteworthy for brainstem gliomas, where two patients achieved both radiologic static disease and discontinued steroid medication. CONCLUSION: Despite moderate toxicity, objective response rates to temozolomide have been low, indicating that temozolomide has minimal activity in the high-grade gliomas of childhood.

[Criteria of diagnosis and grading of oligodendrogliomas or oligo-astrocytomas according to the WHO and Sainte-Anne classifications]. / Oligodendrogliomes et oligo-astrocytomes critères diagnostiques et grading de malignité selon l'OMS et l'hôpital Sainte-Anne.

Two main classification systems are used in France for the histological typing and grading of oligodendrogliomas: the WHO and Sainte-Anne Hospital (SA) classifications. According to the WHO, the typing of diffuse gliomas is based on the predominant cell type, oligodendroglial versus astrocytic. In contrast, the SA classification is based on the distinction of two patterns of tumor growth, solid tumor tissue versus isolated tumor cells and also relies on imaging and clinical features. According to this approach, the SA classification includes in the category of oligodendrogliomas, the fibrillary or gemistocytic diffuse astrocytomas (WHO grade II) as well as a substantial proportion of astrocytomas WHO grade III, 2) the WHO uses multiple histological criteria for the grading of oligodendrogliomas (grade II versus grade III), including the degree of differentiation, cellular atypia, mitotic activity and necrosis. In contrast, the SA grading of these tumors (grade A versus B) only uses two criteria: the presence or absence of endothelial hyperplasia, and the presence or absence of contrast enhancement. This last criterion allows overcoming the problems related to the representativeness of surgical samples. Difficulties and discrepancies regarding the diagnosis of oligodendrogliomas are in part due to the lack of immunomarker for the identification of tumoral oligodendrocytes. The potential interest of new markers of oligodendroglial precursors for the diagnosis of these tumors will further be discussed.

[Reappraisal of the Sainte-Anne Hospital classification of oligodendrogliomas in view of retrospective studies]. / Classification des oligodendrogliomes de l'hôpital Sainte-Anne. Mise au point à l'usage des études rétrospectives.

PURPOSE: Definition of homogeneous tumor groups of oligodendrogliomas or oligo-astrocytomas is a basic condition for an adequate evaluation and comparison of the results of treatments in patients from various institutions. However, increasing discordances are observed in the histological diagnosis of these tumors. The main goal of this study is to assess whether, for retrospective studies, MRI data may serve as a common basis for encompassing asymmetry in diagnosis established according to the WHO or Ste-Anne (SA) classification. PATIENTS AND METHODS: This study included 251 adult patients in whom a SA grade A or B oligodendroglioma or oligo-astrocytoma was newly diagnosed at our institution from 1984 to 2003. Routine histological preparations and post-contrast preoperative MRI/CT-scan were simultaneously reviewed in order to assess the impact on survival of the following features: presence or absence of a polymorphous or gemistocytic astrocytic component, of necrosis and of contrast enhancement (CH); endothelial hyperplasia (EH) assessed as absent, present minor (HE+) or (HE++) when conform to the threshold of HE defined in the SA grading system of oligodendrogliomas. The tumors were graded A: no CH and no EH; in B: CH and /or HE++, and A/B: EH + but no CE. RESULTS: 70.1% of the tumors were classified as "pure" oligodendroglioma, 19.5% as "polymorphous oligo-astroastrocytoma" and 10.3% as "gemistocytic oligo-astrocytoma". In grade A, or B tumors, the presence of a polymorphous or a gemistocytic component had no significant influence on survival; however respectively 53% and 65% of these tumours versus 32% of "pure" oligodendrogliomas were grade B at the time of diagnosis. In either histological subtypes, survival was not significantly different when HE was absent or minor (HE+). After regrouping of the histological subtypes and of the tumors with HE+ or absent, the series included 153 oligodendrogliomas grade A and 98 grade B. Survival in patients with grade A versus grade B tumors was respectively 142 versus 52 months (p<0.0001). In grade B tumors, necrosis had no significant influence on survival. Ring-shaped contrast enhancement surrounding large foci of necrosis was observed in only 4 cases. In tumors with or without CE, patient survival was respectively 148 versus 40 months (p<0.0001). On post contrast MRI done in 235 patients, only 7 tumors (3%) were grade A/B (EH++ but no CH). CONCLUSIONS: From these results and our previous observation that, according to the SA classification of gliomas, only oligodendrogliomas or oligo-astrocytomas may not show CE, we propose that for retrospective studies: 1) tumors diagnosed according to the Ste-Anne classification as oligodendroglioma or oligo-astrocytoma be regrouped in a unique category, 2) independent of their histological type and grade according to the WHO, gliomas that do not show CE be regrouped with SA oligodendrogliomas grade A, 3) concerning gliomas that show CE on MRI: oligodendrogliomas or oligo-astrocytomas WHO grade II or III, as well as WHO secondary glioblastomas or glioblastomas with an oligodendroglial component, be regrouped with SA oligodendrogliomas grade B; however tumors that show ring-like CE surrounding large foci of necrosis and finger-like "peritumoral" edema should be excluded or analysed separately.

[Pediatric supratentorial oligodendrogliomas: Marseilles and Lyons experiences]. / Les oligodendrogliomes supratentoriels de l'enfant. A propos des séries arseillaises et lyonnaises.

BACKGROUND AND PURPOSE: The goal of this study was to analyze the main aspects of oligodendrogliomas observed in children. METHOD: The records of 35 children aged 15 years or younger (23 from Marseilles and 12 from Lyons) were reviewed. Clinical signs and symptoms, imaging findings (CT scan and pre- and post-operative MRI), extent of surgical resection, histology according to the WHO and Ste-Anne grading and survival were analysed. Considering all these factors, a statistical analyzis was undertaken in order to identify prognostic factors. DISCUSSION AND CONCLUSION: Oligodendrogliomas are rare tumors in children. The most important differential diagnosis to discuss is dysembryoplastic neuroepithelial tumor. Our study allowed us to distinguish several subgroups of patients with a different prognosis: thalamic tumors with a dismal prognosis versus hemispheric tumors. A group of cortical tumors we called "DNT-like" (hemispheric cortical tumor, isolated epilepsy, without neurological deficit and reased ICP, without edema and mass effect on MRI) with an excellent prognosis like the group with epilepsy. Histological grading (grade A/grade B and grade II/grade III) is also a prognostic factor.

[Results of the Sainte-Anne - Lyons series of 318 oligodendroglioma in adults]. / Résultats de la série Sainte-Anne - Lyon de 318 oligodendrogliomes intracrâniens de l'adulte.

INTRODUCTION: Incidence of cerebral oligodendrogliomas is increasing because of better recognition made possible by improved classifications. We studied a homogeneous series using the Sainte-Anne grading scale in order to better understanding the history of these tumors with or without treatment and to assess prognosis and associated factors. PATIENTS AND METHODS: A retrospective series of 318 adult patients with oligodendroglioma (OLG) treated at Hôpital Sainte-Anne, Paris (SA) and Hôpital Neurologique, Lyons (L) between 1984 and 2003 was analyzed: 182 grade A OLG (SA + L), 136 grade B among which a homogenous series of 98 (SA) were included. For grade A: age at diagnosis ranged from 21 to 70 (mean: 41), sex ratio was 1.28. For grade B: age at diagnosis ranged from 12 to 75 (mean: 45.5), sex-ratio was 1.58. The main first symptoms were: epilepsy (A: 91.5%; B: 76%), intracranial hypertension (A: 7.9%; B: 14.6%), neurological deficit (A: 5.1%; B: 17.7%). The most frequent locations were: frontal, insular and central for both A and B. Mean size was 55 mm for grade A, 62 mm for B. Calcifications were found in 20% of A, 48.5% of B. No tumor was enhanced on imaging (CT/MRI) in grade A, all but 7 in grade B. All patients underwent surgery either for biopsy (A: 47.2%; B: 53%), or removal which was partial (A: 26.4% vs B: 19.4%) or extended (A: 36.3% vs B: 37.8%). Fifty-six patients underwent 2 procedures and 12 three procedures. Radiotherapy was performed in 76.9% of grade A, and 91% of B patients, in the immediate postoperative period for 71% A and 82.7% B. Chemotherapy was delivered for 36% of grade A (in the event of transformation to grade B or failure of radiotherapy) and 67.5% of B patients. Among grade A tumors, 38% transformed into grade B within a mean delay of 51 months with a mean follow-up of 78 months. RESULTS: Median survival was 136 months for grade A and 52 for grade B. Survival at 5, 10 and 15 was 75.5%, 51% and 22.4% for grade A vs 45.2%, 31.3% and 0% for grade B respectively. In univariate and multivariate analysis, grade A survival was associated with age at diagnosis, tumor size, large removal and response to radiotherapy. Grade B survival was associated with age at diagnosis, wide removal and sharply defined limits of the tumor on imaging. CONCLUSIONS: Analysis of both published data and this series underlines many prognostic parameters. It shows that OLG are heterogeneous tumors even in each grade (A and B). Treatment should consequently progress towards more targeted procedures for patients mainly with postoperative radiotherapy and chemotherapy.