M Polivka

Assistance Publique – Hôpitaux de Paris, Lutetia Parisorum, Île-de-France, France

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Publications (102)240.26 Total impact

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    ABSTRACT: La cryptococcose est une infection opportuniste dont l’infestation pulmonaire est asymptomatique pendant l’enfance. Lors d’une immunodépression cellulaire sévère, fréquemment induite par le VIH, il existe une fongémie, puis passage de la barrière hémato-encéphalique via les monocytes (hypothèse du « cheval de Troie ») et/ou dissémination viscérale. Nous présentons 5 observations de cas extra-cérébraux et extra-pulmonaires.
    Annales de Pathologie 10/2014; 34(5). · 0.24 Impact Factor
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    ABSTRACT: Little is known about the genomic basis of primary central nervous system lymphoma (PCNSL) tumorigenesis. To investigate the mutational profile of PCNSL, we analyzed nine paired tumor and germline DNA samples from PCNSL patients by high throughput exome sequencing. Eight genes of interest have been further investigated by focused resequencing in 28 additional PCNSL tumors to better estimate their incidence. Our study identified recurrent somatic mutations in 37 genes, some involved in key signaling pathways such as NFKB, B cell differentiation and cell cycle control. Focused resequencing in the larger cohort revealed high mutation rates for genes already described as mutated in PCNSL such as MYD88 (38%), CD79B (30%), PIM1 (22%) and TBL1XR1 (19%) and for genes not previously reported to be involved in PCNSL tumorigenesis such as ETV6 (16%), IRF4 (14%), IRF2BP2 (11%) and EBF1 (11%). Of note, only 3 somatically acquired SNVs were annotated in the COSMIC database. Our results demonstrate a high genetic heterogeneity of PCNSL and mutational pattern similarities with extracerebral diffuse large B cell lymphomas, particularly of the activated B-cell (ABC) subtype, suggesting shared underlying biological mechanisms. The present study provides new insights into the mutational profile of PCNSL and potential targets for therapeutic strategies.
    Oncotarget 06/2014; · 6.64 Impact Factor
  • Article: [Chordoma.]
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    ABSTRACT: To review in the literature, all the epidemiological, clinical, radiological, histological and therapeutic data regarding chordomas as well as various notochordal entities: ecchordosis physaliphora, intradural and intraparenchymatous chordomas, benign notochordal cell tumors, parachordomas and extra-axial chordomas. To identify different types of chordomas, including familial forms, associations with tuberous sclerosis, Ollier's disease and Maffucci's syndrome, forms with metastasis and seeding. To assess the recent data regarding molecular biology and progress in targeted therapy. To compare the different types of radiotherapy, especially protontherapy and their therapeutic effects. To review the largest series of chordomas in their different localizations (skull base, sacrum and mobile spine) from the literature.
    Neuro-Chirurgie. 05/2014;
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    ABSTRACT: The aim of this study was to correlate histological features and molecular characteristics in anaplastic oligodendrogliomas (AOs). The histological characteristics of 203 AO patients, enrolled in the French national network POLA, were analyzed. The genomic profiles of 191 cases were studied using genomic arrays. IDH mutational status was assessed by immunohistochemistry and direct sequencing. 1p/19q codeletion was present in 79% of cases and was associated with alpha-internexin expression (P < 10(-4)), IDH1/2 mutation (P < 10(-4)), chromosome 4 loss (P < 10(-3)), and better overall survival (P < 10(-4)). Based on mitotic index, microvascular proliferation (MVP), and necrosis, 3 groups of 1p/19q codeleted AOs were identified: (group 1) AO with more than 5 mitoses per 10-HPF, no MVP, and no necrosis; (group 2) AO with MVP and no necrosis; and (group 3) AO with MVP and necrosis. Compared with group 1, groups 2 and 3 AOs had a higher mean Ki-67 proliferation index and a higher rate of 9p and 9q losses. Compared with group 2, group 3 AOs had a higher number of chromosomal alterations including chromosome 4 loss. In the subgroup of 157 1p/19q codeleted AOs, chromosomal instability was associated with shorter progression-free survival (P = .024) and shorter overall survival (P = .023). The present study shows that oligodendrogliomas with classic histological features remain a molecularly heterogeneous entity and should be stratified according to 1p/19q status because of its major prognostic relevance. Moreover, 1p/19q codeleted AOs are also heterogeneous. Interestingly, mitotic index, MVP, and necrosis help to classify them into 3 groups associated with distinct genomic alterations.
    Neuro-Oncology 04/2014; · 6.18 Impact Factor
  • A. Cazorla, M. Polivka
    Pratique Neurologique - FMC 02/2014; 5(1):78–81.
  • Neurochirurgie. 01/2014;
  • Neurochirurgie 12/2013; 59(6):238. · 0.32 Impact Factor
  • SNCLF - Annual Meeting in Paris, 25-27 November 2013; 11/2013
  • Journal of NeuroVirology 11/2013; · 2.85 Impact Factor
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    ABSTRACT: BACKGROUND: The Human T-cell Leukemia Virus type 1 (HTLV-1) is the causative agent of several inflammatory diseases, including HTLV-1-associated inflammatory myopathies (HAIM). Little is known about the virological and immunological characteristics of this viral disease. OBJECTIVES: To characterize the histological and virological features of HAIM patients, in order to better understand the pathogenetic mechanisms and unravel new biological markers of this disease. STUDY DESIGN: We conducted a retrospective study on 13 patients with HAIM, based on blood and muscle samples. We included blood samples from HTLV-1-infected individuals without myopathy as controls. Muscle biopsies were used for a broad immunohistological evaluation of tissue damage and inflammation, as well as identification of infected cells through in situ hybridization. DNA extracted from patients' PBMC was used to identify the virus genotype by sequencing and to assess the proviral load by quantitative PCR. Anti-viral antibodies in plasma samples were titrated by indirect immunofluorescence. RESULTS: Patients originate from HTLV-1 endemic areas, the West Indies and West Africa. Histological alterations and inflammation in patients muscles were mostly moderate, with classical features of idiopathic myositis and rare HTLV-1-infected infiltrating cells. In all patients, HTLV-1 belonged to the A subtype, transcontinental subgroup. Anti-HTLV-1 antibodies titers were high, but the proviral load was not elevated compared to asymptomatic HTLV-1 carriers. CONCLUSION: We show here that muscle inflammation is moderate in HAIM, and accompanied by a low HTLV-1 proviral load, suggesting that the pathogenetic events do not exactly mirror those of other HTLV-1-associated inflammatory diseases.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 01/2013; · 3.12 Impact Factor
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    ABSTRACT: BACKGROUND: About 90 % of meningiomas are benign (WHO grade I), atypical and anaplastic variants exist (WHO grade II/III, 10 %). Tumour grade has important implications for management. Non-invasive diagnosis of tumour grade is still not feasible. The purpose of this survey was to analyse epidemiological risk factors such as sex, age and location for a higher grade (WHO grade II/III) meningioma in a large surgical series. METHODS: A retrospective study comprising 1,663 patients operated on for an intracranial meningioma in a single tertiary-care centre. The population was analysed for correlations including WHO grade, histological subtype, tumour localisation, patient age and gender. Additionally correlations between Ki67 index/WHO grade and localisation were analysed. RESULTS: A binary logistic regression analysis revealed non-skull base localisation (OR 1.779 [CI 1.069-2.960, p = 0.0027]) and age ≥65 years (OR 1.549 [CI 1.214-2.624, p = 0.012]) as significant risk factors for a higher WHO grade. Male gender showed a trend for a higher risk in χ(2) analysis. An analysis of the Ki67 index revealed an increased index for non-skull base localisation compared with skull base (p < 0.001). Correlation analysis of Ki67 distribution in WHO grade I meningiomas revealed higher Ki67 indices for non skull base localisation (p = 0.0024). CONCLUSIONS: Non-skull base localisation and age ≥65 years are independent risk factors for higher grade meningiomas. In other terms, the malignant potential of skull base meningiomas is low. This information is important when advising a patient about individual treatment options (observation, surgery or radio-surgery) and prognosis.
    Acta Neurochirurgica 01/2013; · 1.55 Impact Factor
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    ABSTRACT: We report the neuropathological findings in 10 HIV‐infected patients treated by combination antiretroviral therapy who developed subacute encephalopathy of rapidly progressive onset. Brain biopsy showed encephalitic lesions variably associated with myelin loss and slight axonal damage. There was inconstant, weak expression of HIV protein p24; tests for other pathogens were negative. The most striking feature was diffuse, perivascular and intraparenchymal infiltration by CD8+ T‐lymphocytes. Six patients improved after the treatment. Four had an unfavorable outcome and died within a year. Post‐mortem in one case confirmed HIV leukoencephalitis with p24‐positive multinucleated giant cells, associated with acute demyelinating encephalomyelitis (ADEM) in the cerebellum. There was diffuse infiltration by CD8+ lymphocytes; CD4+ cells were virtually absent. These cases may represent a specific clinicopathological entity, of which a few comparable cases have been already described. They can be included in the wide framework of immune reconstitution disease. Such syndromes have been described with opportunistic infections, but only seldom with HIV infection of the central nervous system (CNS). Our findings support the hypothesis that CD8+ cytotoxic lymphocytes can be harmful in immune reconstitution disease, particularly in the absence of CD4+ lymphocytes. CD8 cytotoxicity produces an acutization of a smoldering infection and/or an immunopathological reaction similar to ADEM.
    Brain Pathology 01/2013; 23(5). · 4.74 Impact Factor
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    ABSTRACT: Aim. We aimed to analyze the diagnostic criteria proposed by the Bethesda System for Reporting Thyroid Cytopathology for follicular lesions of undetermined significance (FLUS), the risk of cancer and diagnostic improvement with use of immunocytochemistry. Methods. For each FLUS diagnosis, we analyzed the cytological criteria (9 Bethesda criteria), secondary fine-needle aspiration (FNA) results, surgical procedures, contribution of immunocytochemistry with the antibodies cytokeratin 19 (CK19) and monoclonal anti-human mesothelial cell (HBME1). Results. Among patients with 2,210 thyroid FNAs, 244 lesions (337 nodules) were classified as FLUS (11% of all thyroid FNAs). The 3 criteria most often applied were cytological atypia suggesting papillary carcinoma (36%), microfollicular architecture but sparse cellularity (23.1%), cytological atypia (21.5%). With secondary FNA, 48.8% of nodules were reclassified as benign. For about half of all cases (41.4% for the first FNA, 57.6% for the second FNA), immunocytochemistry helped establishing a diagnosis favoring malignant or benign. No benign immunocytochemistry results were associated with a malignant lesion. In all, 22.5% of the 39 removed nodules were malignant. Conclusion. The FLUS category is supported by well-described criteria. The risk of malignancy in our series was 22.5%. Because we had no false-negative immunocytochemistry results, immunocytochemistry could be helpful in FLUS management.
    Journal of thyroid research. 01/2013; 2013:250347.
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    ABSTRACT: PURPOSE: Our objective was to identify the genetic changes involved in primary central nervous system lymphoma (PCNSL) oncogenesis and evaluate their clinical relevance. EXPERIMENTAL DESIGN: We investigated a series of 29 newly diagnosed, HIV-negative, PCNSL patients using high-resolution single-nucleotide polymorphism (SNP) arrays (n = 29) and whole-exome sequencing (n = 4) approaches. Recurrent homozygous deletions and somatic gene mutations found were validated by quantitative real-time PCR and Sanger sequencing, respectively. Molecular results were correlated with prognosis. RESULTS: All PCNSLs were diffuse large B-cell lymphomas, and the patients received chemotherapy without radiotherapy as initial treatment. The SNP analysis revealed recurrent large and focal chromosome imbalances that target candidate genes in PCNSL oncogenesis. The most frequent genomic abnormalities were (i) 6p21.32 loss (HLA locus), (ii) 6q loss, (iii) CDKN2A homozygous deletions, (iv) 12q12-q22, and (v) chromosome 7q21 and 7q31 gains. Homozygous deletions of PRMD1, TOX, and DOCK5 and the amplification of HDAC9 were also detected. Sequencing of matched tumor and blood DNA samples identified novel somatic mutations in MYD88 and TBL1XR1 in 38% and 14% of the cases, respectively. The correlation of genetic abnormalities with clinical outcomes using multivariate analysis showed that 6q22 loss (P = 0.006 and P = 0.01) and CDKN2A homozygous deletion (P = 0.02 and P = 0.01) were significantly associated with shorter progression-free survival and overall survival. CONCLUSIONS: Our study provides new insights into the molecular tumorigenesis of PCNSL and identifies novel genetic alterations in this disease, especially MYD88 and TBL1XR1 mutations activating the NF-κB signaling pathway, which may be promising targets for future therapeutic strategies. Clin Cancer Res; 18(19); 5203-11. ©2012 AACR.
    Clinical Cancer Research 07/2012; 18(19):5203-5211. · 7.84 Impact Factor
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    ABSTRACT: To detect the presence of hypoxic tissue, which is known to increase the radioresistant phenotype, by its uptake of fluoromisonidazole (18F) (FMISO) using hybrid positron emission tomography/computed tomography (PET/CT) imaging, and to compare it with the glucose-avid tumor tissue imaged with fluorodeoxyglucose (18F) (FDG), in residual postsurgical skull base chordoma scheduled for radiotherapy. Seven patients with incompletely resected skull base chordomas were planned for high-dose radiotherapy (dose ≥70 Gy). All 7 patients underwent FDG and FMISO PET/CT. Images were analyzed qualitatively by visual examination and semiquantitatively by computing the ratio of the maximal standardized uptake value (SUVmax) of the tumor and cerebellum (T/C R), with delineation of lesions on conventional imaging. Of the eight lesion sites imaged with FDG PET/CT, only one was visible, whereas seven of nine lesions were visible on FMISO PET/CT. The median SUVmax in the tumor area was 2.8 g/mL (minimum 2.1; maximum 3.5) for FDG and 0.83 g/mL (minimum 0.3; maximum 1.2) for FMISO. The T/C R values ranged between 0.30 and 0.63 for FDG (median, 0.41) and between 0.75 and 2.20 for FMISO (median,1.59). FMISO T/C R >1 in six lesions suggested the presence of hypoxic tissue. There was no correlation between FMISO and FDG uptake in individual chordomas (r = 0.18, p = 0.7). FMISO PET/CT enables imaging of the hypoxic component in residual chordomas. In the future, it could help to better define boosted volumes for irradiation and to overcome the radioresistance of these lesions. No relationship was founded between hypoxia and glucose metabolism in these tumors after initial surgery.
    International journal of radiation oncology, biology, physics 03/2012; 84(3):681-7. · 4.59 Impact Factor
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    ABSTRACT: To describe the pseudotumoural presentation of neuro-Behçet's disease (NBD). We report here the main characteristics, treatment and outcome of 23 patients (5 personal cases and 18 patients from the literature) with a pseudotumoural presentation of NBD. Pseudotumoural NBD patients were compared with 69 consecutive patients, with a classical form of NBD. The median age was 39 (range 27-48 years) years, with a male predominance (65.2%). Clinical features of the pseudotumoural NBD included hemi- or tetra-pyramidal symptoms (n = 20), headache (n = 17), cerebellar syndrome (n = 3), sphincter impotence (n = 3) and pseudobulbar signs (n = 2). CNS imaging showed pseudotumoural lesions mainly in the capsulo-thalamic area (69.6 vs 11.6% for classical NBD; P < 0.01). Histological analysis revealed necrotic lesions with perivascular inflammatory infiltrate without signs of tumoural or infectious lesions. Patients with pseudotumoural NBD had more severe initial disability status (Rankin's score ≥3 in 65.2 vs 24.7%; P < 0.01) and had a 3 years' longer duration between neurological signs and BD diagnosis (P = 0.01) compared with patients with classical NBD. Treatment consisted of CSs (n = 21, 95.5%) and immunosuppressive agents (n = 10, 35.7%) that led to complete clinical and imaging remission in 60.9% of patients. Two (8.7%) of the 23 patients with pseudotumoural NBD died of bedridden state complications. The pseudotumoural form of NBD is a rare and life-threatening condition.
    Rheumatology (Oxford, England) 02/2012; 51(7):1216-25. · 4.24 Impact Factor
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    ABSTRACT: The endoscopic approach has gained an increased popularity in recent years for the biopsy and, in selected cases, the removal of tumors of the posterior third ventricle and pineal region. The authors report their experience on a series of 20 patients discussing also the technical limitations and complication avoidance. This is a prospective study of 20 patients with posterior third ventricle and pineal region tumors surgically managed by endoscopic biopsy and/or excision and simultaneous third ventriculostomy. The removal of the lesion could be achieved in 12 cases whereas in 8, only a biopsy could be performed. A histological diagnosis could be obtained in all cases. No delayed third ventricular stoma failures were recorded in any patient at the latest follow-up (mean follow-up, 39 months). Severe postoperative complications were recorded in 2 out of 12 cases of tumor removal attempt and in zero out of eight cases of biopsy. A delayed (3 weeks) postoperative mortality occurred in a patient harboring a GBM that developed an intratumoral hematoma 48 h postoperatively, one patient was in a vegetative state. Transient postoperative complications included: nausea and vomiting (five cases) and diplopia (two cases). One patient developed a bilateral ophthalmoplegia that recovered within 6 months due to residual tumor hemorrhage. Higher rate of complications was found in the case of vascularized and/or larger lesions. Endoscopic management of posterior third ventricle lesions may represent an effective option. However, though biopsies remain often a safe procedure, tumor excision should be limited to highly selected cases (cystic, poorly vascularized, and/or smaller than 2.5-cm lesions).
    Neurosurgical Review 01/2012; 35(3):331-38; discussion 338-40. · 1.97 Impact Factor
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    ABSTRACT: Thyroid nodules are relatively common (7% of the population) but are malignant in only 5%-10% of cases. Fine-needle aspiration (FNA) to detect cancer can have > 90% sensitivity but only 50%-65% specificity because of false-positive results, which necessitates surgical controls. We aimed to assess the diagnostic accuracy of immunocytochemistry (ICC) of thyroid FNA to improve its sensitivity and specificity. We prospectively collected 2038 thyroid FNAs, of which 1397 were FNA biopsies with liquid-based cytology (Thin-Prep-Hologic®). ICC with cytokeratin 19 and HBME1 antibodies (Dako® A/S) was used for all malignant cases and cases of atypical cells of undetermined significance (AUS), follicular neoplasm (FN), and nodules suspicious for malignancy-papillary thyroid carcinoma (SM-PTC) as well as some benign cases (abnormal features on radiography or benign on secondary FNA). ICC results were defined as "non-contributory," "favoring benign," "favoring malignant," or "indeterminate." Results for 150 cases were compared with histological controls for diagnostic accuracy. Of these 150 cases ICC was helpful for benign or malignant triage of 48 cases of AUS, FN, and SM-PTC (42% of these lesions). Six (4%) ICC results were false positive (favoring malignant with benign histology) but none were false negative (favoring benign with malignant histology). Results for indeterminate cytological cases favored malignant or benign disease with sensitivity, specificity, and negative and positive predictive values of 100%, 85.2%, 100%, and 86.2%, respectively. ICC of thyroid FNAs with cytokeratin 19 and HBME1 antibodies can reduce the false-positive and false-negative results of single morphological analyses. It can increase the sensitivity and specificity of diagnosis, thus improving diagnostic accuracy and reducing the need for surgical controls.
    Thyroid: official journal of the American Thyroid Association 08/2011; 21(10):1067-73. · 2.60 Impact Factor
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    ABSTRACT: Previous studies of chordoma have focused on either surgery, radiotherapy, or particular tumor locations. This paper reviewed the outcomes of surgery and proton radiotherapy with various tumor locations. Between 2001 and 2008, 40 patients with chordomas of the skull base and cervical spine had surgery at our hospital. Most patients received proton therapy. Their clinical course was reviewed. Age, sex, tumor location, timing of surgery, extent of resection, and chondroid appearance were evaluated in regard to the progression-free survival (PFS) and overall survival (OS). The primary surgery (PS) group was analyzed independently. The extensive resection rate was 42.5%. Permanent neurological morbidity was seen in 3.8%. Radiotherapy was performed in 75% and the mean dose was 68.9 cobalt gray equivalents. The median follow-up was 56.5 months. The 5-year PFS and OS rates were 70% and 83.4%, respectively. Metastasis was seen in 12.5%. The tumor location at the cranio-cervical junction (CCJ) was associated with a lower PFS (P = 0.007). In the PS group, a younger age and the CCJ location were related to a lower PFS (P = 0.008 and P < 0.001, respectively). The CCJ location was also related to a lower OS (P = 0.043) and it was more common in young patients (P = 0.002). Among the survivors, the median of the last Karnofsky Performance Scale score was 80 with 25.7% of patients experiencing an increase and 11.4% experiencing a decrease. Multimodal surgery and proton therapy thus improved the chordoma treatment. The CCJ location and a younger age are risks for disease progression.
    Neurosurgical Review 08/2011; 35(2):171-82; discussion 182-3. · 1.97 Impact Factor
  • Neurology 07/2011; 77(3):263. · 8.30 Impact Factor

Publication Stats

894 Citations
240.26 Total Impact Points

Institutions

  • 2009–2014
    • Assistance Publique – Hôpitaux de Paris
      • Department of Radiology
      Lutetia Parisorum, Île-de-France, France
  • 2003–2014
    • Hôpital Ambroise Paré – Hôpitaux universitaires Paris Ile-de-France Ouest
      Billancourt, Île-de-France, France
    • Centre Hospitalier Régional Universitaire de Lille
      Lille, Nord-Pas-de-Calais, France
  • 2013
    • Heinrich-Heine-Universität Düsseldorf
      • Neurochirurgische Klinik
      Düsseldorf, North Rhine-Westphalia, Germany
  • 2011
    • Aichi Medical University
      Japan
  • 2005–2011
    • Hôpital La Pitié Salpêtrière (Groupe Hospitalier "La Pitié Salpêtrière - Charles Foix")
      • Service de Neurochirurgie
      Lutetia Parisorum, Île-de-France, France
    • CHU de Lyon - Hôpital Neurologique et Neurochirurgical Pierre Wertheimer
      Lyons, Rhône-Alpes, France
  • 2007
    • Pierre and Marie Curie University - Paris 6
      • Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière
      Paris, Ile-de-France, France