Drug screening with a novel tumor-derived cell line identified alternative therapeutic options for patients with atypical teratoid/rhabdoid tumor.

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare intracranial tumor occurring predominantly in young children. The prognosis is poor, and no effective treatment is currently available. To develop novel effective therapies, there is a need for experimental models for AT/RT. In this research, we established a cell line from a patient's AT/RT tissue (designated ATRT_OCGH) and performed drug screening using 164 FDA-approved anti-cancer agents, to identify candidates for therapeutic options. We found that bortezomib, a proteasome inhibitor, was among the agents for which the cell line showed high sensitivity, along with tyrosine kinase inhibitors, topoisomerase inhibitors, and histone deacetylase inhibitors, which are known to exert anti-AT/RT effects. Concomitant use of panobinostat potentiated the inhibitory effect of bortezomib on AT/RT cell proliferation. Our findings may provide a rationale for considering combination therapy of panobinostat and bortezomib for treatment of AT/RT.

Ethanol extract of Magnoliae cortex (EEMC) limits teratoma formation of pluripotent stem cells by selective elimination of undifferentiated cells through the p53-dependent mitochondrial apoptotic pathway.

BACKGROUND: Induced pluripotent stem cells (iPSCs) are regarded as the best potential cell source for cell-based regenerative medicine. To develop a safe and efficient iPSC-based cell therapy, it is very important to avoid possible teratoma formation, which can arise from undifferentiated iPSCs (USCs) remaining among differentiated cell products. Dried bark of Magnolia officinalis (Magnolia cortex, MC) has long been used in traditional medicine to treat gastrointestinal ailments and allergic diseases, and has shown have various pharmacological activities, including anti-bacterial, anti-inflammatory, and anti-cancer effects. However, its effects on iPSCs have not yet been examined. PURPOSE: In this study, we investigated the selective cytotoxic effects of ethanol extract of MC (EEMC) on undifferentiated iPSCs and elucidated the underlying apoptotic mechanisms in detail. We also investigated the inhibitory effects of EEMC on teratoma formation via in ovo experiments. RESULTS: We found that EEMC greatly reduced cell growth and induced apoptotic cell death in USCs, but not in differentiated or normal cells. EEMC caused G2/M cell cycle arrest, mitochondrial damage, and caspase activation of USCs, accompanied by p53 accumulation. In p53KO human iPSCs, EEMC had no cytotoxicity, reinforcing that EEMC-mediated apoptosis of USCs is p53-dependent. EEMC did not cause DNA damage in iPSC-derived differentiated cells. In ovo teratoma formation assay revealed that EEMC treatment before injection efficiently eliminated USCs and prevented teratoma formation. CONCLUSIONS: These results collectively indicate that EEMC has potent anti-teratoma activity, and therefore can be used for the development of safe iPSC-based therapy.

Efficient Generation of Non-Integration and Feeder-Free Induced Pluripotent Stem Cells from Human Peripheral Blood Cells by Sendai Virus.

BACKGROUND/AIMS: Induced pluripotent stem cells (iPSCs) hold great promise for regenerative medicine, disease modeling, and drug development. Thus, generation of non-integration and feeder-free iPSCs is highly desirable for clinical applications. Peripheral blood mononuclear cells (PBMCs) are an attractive resource for cell reprogramming because of their properties of easy accessibility and the limited invasiveness of blood collection. However, derivation of iPSCs is technically demanding due to the low reprogramming efficiency and nonadherent features of PBMCs. METHODS: iPSCs were generated from PBMCs using non-integrative Sendai viruses carrying the reprogramming factors Oct4, Sox2, Klf4, and cMyc. The derived iPSCs were fully characterized at the levels of gene and protein, and then they were transplanted into immunocompromised mice for evaluation of in vivo differentiation potential. Three types of extracellular substrates (Geltrex, vitronectin, and rhLaminn-521) were tested for their influences on cell reprogramming under feeder-free conditions. We also sought to establish approaches to efficient cell recovery post-thaw and single cell passaging of iPSCs employing Rock inhibitors. RESULTS: iPSCs were efficiently generated from PBMCs under feeder-free conditions. The derived iPSCs proved to be pluripotent and transgene-free. Furthermore, they demonstrated multi-lineage differentiation potentials when transplanted into immunocompromised mice. Among the three substrates, Geltrex and rhLaminin-521 could effectively support the initial cell reprogramming process, but vitronectin failed. However, the vitronectin, similar to Geltrex and rhLaminin-521, could effectively maintain cell growth and expansion of passaged iPSCs. In addition, RevitaCell supplement (RVC) was more potent on cell recovery post-thaw than Y-27632. And RVC and Y-27632 could significantly increase the cell survival when the cells were passaged in single cells, and they showed comparable effectiveness on cell recovery. CONCLUSION: We have successfully derived non-integration and feeder-free human iPSCs from peripheral blood cells, and established effective strategies for efficient cell recovery and single cell passaging. This study will pave the way to the derivation of clinical-grade human iPSCs for future clinical applications.

Influence of hyperthermal regimes on experimental teratoma development in vitro.

We screened for the impact of hyperthermal regimes varying in the cumulative equivalent minutes at 43°C (CEM43°C) and media composition on tumour development using an original teratoma in vitro model. Rat embryos (three germ layers) were microsurgically isolated and cultivated at the air-liquid interface. During a two week period, ectodermal, mesodermal and endodermal derivatives developed within trilaminar teratomas. Controls were grown at 37°C. Overall growth was measured, and teratoma survival and differentiation were histologically assessed. Cell proliferation was stereologically quantified by the volume density of Proliferating Cell Nuclear Antigen. Hyperthermia of 42°C, applied for 15 minutes after plating (CEM43°C 3.75 minutes), diminished cell proliferation (P Ë‚ .0001) and enhanced differentiation of both myotubes (P Ë‚ .01) and cylindrical epithelium (P Ë‚ .05). Hyperthermia of 43°C applied each day for 30 minutes during the first week (CEM43°C 210 minutes) impaired overall growth (P Ë‚ .01) and diminished cell proliferation (P Ë‚ .0001). Long-term hyperthermia of 40.5°C applied for two weeks (CEM43°C 630 minutes) significantly impaired survival (P Ë‚ .005). Long-term hyperthermia of 40.5°C applied from the second day when differentiation of tissues begins (CEM43°C 585 minutes) impaired survival (P Ë‚ .0001), overall growth (P Ë‚ .01) and cartilage differentiation (P Ë‚ .05). No teratomas survived extreme regimes: 43°C for 24 hours (CEM43°C 1440 minutes), hyperthermia in the scant serum-free medium (CEM43°C 630 minutes) or treatment with an anti-HSP70 antibody before long-term hyperthermia 40.5°C from the second day (CEM43°C 585 minutes). This in vitro research provided novel insights into the impact of hyperthermia on the development of experimental teratomas from their undifferentiated sources and are thus of potential interest for future therapeutic strategies in corresponding in vivo models.

Optimization of reprogramming culture conditions for the generation of induced pluripotent stem cells from Col1a1 4F2A-Oct4-GFP mice with high efficiency.

A reprogrammable transgenic mouse strain, called Col1a1 4F2A-Oct4-GFP, was bred for the present study. Because the somatic cells of this mouse strain contain only two copies of each Yamanaka factor, these animals are inefficient at producing induced pluripotent stem cells (iPSCs; approx. 0.005%) under traditional culture conditions. With an optimized culture condition, the iPSC production rate of mouse embryonic fibroblasts (MEFs) of Col1a1 4F2A-Oct4-GFP mice (MEFCol1a14F2A-Oct4-GFP ) was increased to approximately 8%. Further, promotion of cell proliferation by serum supplementation did not enhance iPSC production. Inhibition of transforming growth factor ß (TGF-ß) in the serum by SB431542 neither affected the growth rate of MEFCol1a14F2A-Oct4-GFP nor promoted iPSC production. However, the use of the gamma-irradiated STO-NEO-LIF (γSNL) cells to serve as feeders for iPSC production resulted in a 5-fold higher rate of iPSC production than the use of γMEFICR feeders. Interestingly, the use of SB431542 with the γMEFICR -adopted system could eliminate this difference. RT-PCR-based comparative analysis further demonstrated that TGF-ß expression was 10-fold higher in γMEFICR than in γSNL cells. Consistent with previous reports, mesenchymal to epithelial transition was found to participate in the initial steps of reprogramming in the specific context of MEFCol1a14F2A-Oct4-GFP . Moreover, we found that the initial seeding density is one of the pivotal factors for determining a high efficiency of iPSC generation. The iPSCs efficiently generated from our MEFCol1a14F2A-Oct4-GFP resembled mouse embryonic stem cells (mESCs) in aspects of teratoma formation and germline transmission. Depending on the culture conditions, our Col1a1 4F2A-Oct4-GFP mouse system can generate bona fide iPSCs with variable efficiencies, which can serve as a tool for interrogating the route taken by cells during somatic reprogramming.

[Thyroid carcinoma on struma ovarii: Diagnosis and treatment]. / Cancer thyroïdien sur struma ovarii : généralités et principes de prise en charge.

Thyroid carcinoma on struma ovarii (TCSO) is a rare ovarian tumour, derivate from monodermic teratomas. It represents about 0.01% of overall ovarian tumours and 5 to 10% of struma ovarii. The diagnosis is histologic and retrospective after pelvic surgery; radiographic imaging being unspecific. Because of its rarity, the treatment of TCSO is not consensual and should be validated in multidisciplinary team involved in rare ovarian carcinoma. The first treatment is a surgical removal, with a laparoscopic approach. A fertility-conservative surgery is recommended for young women. If the tumour is unresectable and/or with metastatic spread, an adjuvant iodine 131 treatment might be proposed after thyroidectomy. Recurrence of TCSO should be taken care of as a thyroid carcinoma with tyrosine kinase inhibitor in case of progressive distant relapse, refractory to iodine 131 treatment. If the recurrence is localised, a complete surgery is the preferred option. There is no gold standard for the follow up.

Malignant transformation of mature cystic teratoma of the ovary: 30-year experience of a single tertiary care center.

OBJECTIVE: To review the authors' experience with this rare disease and describe their management modality and the outcome. MATERIAL AND METHODS: From January 1983 to December 2013, 13 patients with malignant transformation arising in ovarian MCT were treated at the Division of Gynecologic Oncology in the University of Manitoba. Demographic characteristics, symptoms, signs, stage, mode of therapy, and results of follow-up were reviewed retrospectively. RESULTS: Median age at diagnosis was 53 years (range 25-65). The most common presenting symptom was a palpable mass in nine cases. Squamous cell carcinoma (SCC) was found in 38% (five cases), adenocarcinoma in 15% (two cases), anaplastic carcinoma in 8% (one case), and papillary thyroid carcinoma in 38% (five cases). Eight cases were Stage I, two cases were Stage II, and three cases were Stage III. All patients underwent surgery. Five patients received adjuvant treatment with platinum-based chemotherapy + pelvic radiation. Four patients had recurrent disease (two SCC and two adenocarcinoma). Three patients died of disease after recurrence. The median follow up period of the entire patient population was 60 months, with a three-year overall survival of 76%. CONCLUSION: Malignant transformation of MCT is large ovarian tumors that mainly occur in patients in their fifth and sixth decades of life. They often present as incidental pathologic findings after surgery for MCT. SCC has traditionally been the most common pathology, however in the present series, the authors found that papillary thyroid carcinoma was equally common. Platinum-based chemotherapy with pelvic radiation in early stage (including Stage IA) and locally recurrent dis- ease should be offered. Advanced stages and mucinous adenocarcinoma represent a poorer prognosis despite adjuvant treatment. In patients with papillary thyroid carcinoma, conservative surveillance in early stage and adjuvant total thyroidectomy with radioactive iodine treatment in advanced stage disease appears to be an effective treatment.

Generation of human induced pluripotent stem (Ips) cells in serum- and feeder-free defined culture and TGF-Β1 regulation of pluripotency.

Human Embryonic Stem cells (hESCs) and human induced Pluripotent Stem cells (hiPSCs) are commonly maintained on inactivated mouse embryonic fibroblast as feeder cells in medium supplemented with FBS or proprietary replacements. Use of culture medium containing undefined or unknown components has limited the development of applications for pluripotent cells because of the relative lack of knowledge regarding cell responses to differentiating growth factors. In addition, there is no consensus as to the optimal formulation, or the nature of the cytokine requirements of the cells to promote their self-renewal and inhibit their differentiation. In this study, we successfully generated hiPSCs from human dental pulp cells (DPCs) using Yamanaka's factors (Oct3/4, Sox2, Klf4, and c-Myc) with retroviral vectors in serum- and feeder-free defined culture conditions. These hiPSCs retained the property of self-renewal as evaluated by the expression of self-renewal marker genes and proteins, morphology, cell growth rates, and pluripotency evaluated by differentiation into derivatives of all three primary germ layers in vitro and in vivo. In this study, we found that TGF-ß1 increased the expression levels of pluripotency markers in a dose-dependent manner. However, increasing doses of TGF-ß1 suppressed the growth rate of hiPSCs cultured under the defined conditions. Furthermore, over short time periods the hiPSCs cultured in hESF9 or hESF9T exhibited similar morphology, but hiPSCs maintained in hESF9 could not survive beyond 30 passages. This result clearly confirmed that hiPSCs cultured in hESF9 medium absolutely required TGF-ß1 to maintain pluripotency. This simple serum-free adherent monoculture system will allow us to elucidate the cell responses to growth factors under defined conditions and can eliminate the risk might be brought by undefined pathogens.

Tbx3 and Nr5α2 play important roles in pig pluripotent stem cells.

Pigs are valuable animal models in pre-clinical research due to their anatomical and similarity to human-beings. Little is known about porcine embryonic development and porcine pluripotent stem cells. Recently, porcine-induced pluripotent stem cells (piPSCs) have been generated with Oct4 (Pou5f1), Sox2, Klf4 and c-Myc (termed OSKM, 4 F). Here, we found two other factors (Tbx3 and Nr5α2, termed TN), with important roles in piPSCs induction. They could improve the generation of piPSCs by supplementing these two factors on the basis of OSKM (OSKMTN, 6 F) orientated to mouse ESCs-like. Surprisingly, Nr5α2 alone could induce piPSCs formation in the presence or absence of c-Myc. These results suggested that Tbx3 and Nr5α2 may have vital roles in Sus scrofa and proposed new insights into pig pluripotent stem cells.

[Medical research through historical resources. Talking objects: a case of a parasitic perineal monstrosity]. / La ricerca medica attraverso la ricerca storica: mostri e mostruosità. Di una mostruosità parassitaria felicemente risolta con operazione chirurgica.

A case of a parasitic perineal monstrosity from the collection of the Pathology Museum of the University of Florence, is described on the basis of the original medical records and illustrations. The surgeon Giorgio Pellizzari (1814-1894) first reported this extraordinary case of sacrococcygeal teratoma containing a rudimentary inferior limb. Reader of Descriptive Anatomy, Pellizzari was a well-known Anatomy Dissector and Curator of the Physiological Museum of the Regio Arcispedale di Santa Maria Nuova in Florence. This report underlines the importance of studying the archive material in order to thoroughly comprehend a single museum talking object. This handling of matters will help to turn anatomical collections into a unique teaching toolfor modern medical practice and a noteworthy documentation of scientific, artistic and historical value. Through analysis of the original catalogue and investigation by means of modern scientific techniques, discovering the story behind the object becomes afeasible challenge.

Human mid-trimester amniotic fluid stem cells cultured under embryonic stem cell conditions with valproic acid acquire pluripotent characteristics.

Human mid-trimester amniotic fluid stem cells (AFSC) have promising applications in regenerative medicine, being broadly multipotent with an intermediate phenotype between embryonic (ES) and mesenchymal stem cells (MSC). Despite this propluripotent phenotype, AFSC are usually cultured in adherence in a serum-based expansion medium, and how expansion in conditions sustaining pluripotency might affect their phenotype remains unknown. We recently showed that early AFSC from first trimester amniotic fluid, which endogenously express Sox2 and Klf4, can be reprogrammed to pluripotency without viral vectors using the histone deacetylase inhibitor valproic acid (VPA). Here, we show that mid-trimester AFSC cultured under MSC conditions contained a subset of cells endogenously expressing telomerase, CD24, OCT4, C-MYC, and SSEA4, but low/null levels of SOX2, NANOG, KLF4, SSEA3, TRA-1-60, and TRA-1-81, with cells unable to form embryoid bodies (EBs) or teratomas. In contrast, AFSC cultured under human ESC conditions were smaller in size, grew faster, formed colonies, upregulated OCT4 and C-MYC, and expressed KLF4 and SOX2, but not NANOG, SSEA3, TRA-1-60, and TRA-1-81. Supplementation with VPA for 5 days further upregulated OCT4, KLF4, and SOX2, and induced expression of NANOG, SSEA3, TRA-1-60, and TRA-1-81, with cells now able to form EBs and teratomas. We conclude that human mid-trimester AFSC, which may be isolated autologously during pregnancy without ethics restriction, can acquire pluripotent characteristics without the use of ectopic factors. Our data suggest that this medium-dependant approach to pluripotent mid-trimester AFSC reflects true reprogramming and not the selection of prepluripotent cells.

A novel strategy to derive iPS cells from porcine fibroblasts.

Induced pluripotent stem (iPS) cell technology demonstrates that somatic cells can be reprogrammed to a pluripotent state by over-expressing four reprogramming factors. This technology has created an interest in deriving iPS cells from domesticated animals such as pigs, sheep and cattle. Moloney murine leukemia retrovirus vectors have been widely used to generate and study mouse iPS cells. However, this retrovirus system infects only mouse and rat cells, which limits its use in establishing iPS cells from other mammals. In our study, we demonstrate a novel retrovirus strategy to efficiently generate porcine iPS cells from embryonic fibroblasts. We transfected four human reprogramming factors (Oct4, Sox2, Klf4 and Myc) into fibroblasts in one step by using a VSV-G envelope-coated pantropic retrovirus that was easily packaged by GP2-293 cells. We established six embryonic stem (ES)-like cell lines in human ES cell medium supplemented with bFGF. Colonies showed a similar morphology to human ES cells with a high nuclei-cytoplasm ratio and phase-bright flat colonies. Porcine iPS cells could form embryoid bodies in vitro and differentiate into the three germ layers in vivo by forming teratomas in immunodeficient mice.

αvß3 imaging can accurately distinguish between mature teratoma and necrosis in 18F-FDG-negative residual masses after treatment of non-seminomatous testicular cancer: a preclinical study.

PURPOSE: We assessed whether imaging α(v)ß(3) integrin could distinguish mature teratoma from necrosis in human non-seminomatous germ cell tumour (NSGCT) post-chemotherapy residual masses. METHODS: Human embryonal carcinoma xenografts (six/rat) were untreated (controls) or treated to form mature teratomas with low-dose cisplatin and all-trans retinoic acid (ATRA) over a period of 8 weeks. In another group, necrosis was induced in xenografts with high-dose cisplatin plus etoposide (two cycles). (18)F-Fluorodeoxyglucose ((18)F-FDG) small animal positron emission tomography (SA PET) imaging was performed in three rats (one control and two treated for 4 and 8 weeks with cisplatin+ATRA). Imaging of α(v)ß(3) expression was performed in six rats bearing mature teratomas and two rats with necrotic lesions on a microSPECT/CT device after injection of the tracer [(99m)Tc]HYNIC-RGD [6-hydrazinonicotinic acid conjugated to cyclo(Arg-Gly-Asp-D-Phe-Lys)]. Correlative immunohistochemistry studies of human and mouse α(v)ß(3) expression were performed. RESULTS: Cisplatin+ATRA induced differentiation of the xenografts. After 8 weeks, some glandular structures and mesenchymal cells were visible; in contrast, control tumours showed undifferentiated tissues. SA PET imaging showed that mature teratoma had very low avidity for (18)F-FDG [mean standardised uptake value (SUV(mean)) = 0.48 ± 0.05] compared to untreated embryonal carcinoma (SUV(mean) = 0.92 ± 0.13) (p = 0.005). α(v)ß(3) imaging accurately distinguished mature teratoma (tumour to muscle ratio = 4.29 ± 1.57) from necrosis (tumour to muscle ratio = 1.3 ± 0.26) (p = 0.0002). Immunohistochemistry studies showed that α(v)ß(3) integrin expression was strong in the glandular structures of mature teratoma lesions and negative in host stroma. CONCLUSION: Imaging α(v)ß(3) integrin accurately distinguished mature teratoma from necrosis following cisplatin-based treatment in human NSGCT xenografts.

[Inhibitory effect of matrine on proliferation of human ovary malignant teratoma cell line PA-1 in vitro].

OBJECTIVE: To study the effect of matrine (MAT) on the proliferation of human ovary malignant teratoma cell line PA-1 in vitro. METHODS: PA-1 cells allocated in different groups were treated with different concentrations (0.25 mg/mL, 0.5 mg/mL and 1.0 mg/mL) of MAT. The inhibitory effect of MAT and its dose- and time-effect relationship were detected with MTT; the apoptosis rate and cell cycle were evaluated by flow cytometry; and the changes of bcl-2/bax mRNA expression in cells were measured using semi-quantitative RT-PCR. RESULTS: After being exposed to MAT, the PA-1 cell proliferation was decreased in a concentration- and time-dependent manner; cell apoptosis rate raised as the increasing concentration of MAT and acting time; cells retarded at G1 phase in the cell cycle dose-dependently; and the bcl-2/bax mRNA expression in cells dawn-regulated significantly. CONCLUSION: MAT can dose- and time-dependently inhibit the proliferation of PA-1 cell by reducing bcl-2/bax mRNA ratio to produce a G1 phase arresting in cell cycle.

Implantes peritoneales de tejido glial maduro (gliomatosis peritoneal) y de otros tejidos maduros asociados a teratoma ovárico inmaduro / Peritoneal implants of mature glial tissue (gliomatosis peritonei) and other mature tissues associated with ovarian teratoma

La gliomatosis peritoneal es una forma de extensión muy poco frecuente de los teratomas ováricos. Se caracteriza por la implantación miliar de tejido glial dentro de la cavidad peritoneal en pacientes con teratomas ováricos, generalmente inmaduros. Puede semejar un cuadro de carcinomatosis peritoneal. A pesar de su extensión intraperitoneal, la gliomatosis peritoneal no afecta adversamente al pronóstico del teratoma ovárico primario si los implantes de tejido glial se componen de tejido maduro y, por tanto, justifica tratamientos conservadores. El grado histológico del teratoma es el factor pronóstico que debe indicar el tratamiento complementario necesario. Su pronóstico es bueno, aunque se han descrito casos de malignización

Peritoneal gliomatosis is a very rare metastatic form of ovarian teratoma, characterized by miliary dissemination of glial tissue inside the peritoneal cavity in patients with an ovarian ­ usually immature ­ teratoma. Peritoneal gliomatosis may resemble peritoneal carcinomatosis. Despite peritoneal dissemination, if the glial tissue implants are composed of mature tissue, peritoneal gliomatosis does not adversely affect the prognosis of the primary ovarian teratoma. Consequently, conservative treatment is warranted. The main prognostic factor is the histological grade of the teratoma, which indicates the required complementary treatment. The prognosis of peritoneal gliomatosis is favorable, although cases of malignant transformation have been reporte (AU)

Generation and characterization of novel tetracycline-inducible pancreatic transcription factor-expressing murine embryonic stem cell lines.

Pancreatic development in mammals is controlled in part by the expression and function of numerous genes encoding transcription factors. Yet, how these regulate each other and their target genes is incompletely understood. Embryonic stem (ES) cells have recently been shown to be capable of differentiating into pancreatic progenitor cells and insulin-producing cells, representing a useful in vitro model system for studying pancreatic and islet development. To generate tools to study the relationships of transcription factors in pancreatic development we have established seven unique mouse ES cell lines with tetracycline-inducible expression of either Hnf4alpha, Hnf6, Nkx2.2, Nkx6.1, Pax4, Pdx1, and Ptf1a cDNAs. Each of the cell lines was characterized for induction of transgene expression after exposure to doxycycline (DOX) by quantitative real-time PCR and immunofluorescence microscopy. Transgene expression in the presence of DOX was at least 97-fold that seen in untreated cells. Immunofluorescent staining of DOX-treated cultures showed efficient (>95% of cells) transgene protein expression while showing <5% positive staining in uninduced cells. Each of the ES cell lines maintained their pluripotency as measured by teratoma formation. Furthermore, transgene expression can be efficiently achieved in vivo through DOX administration to mice. The establishment of ES cell lines with temporally controllable induction of critical pancreatic transcription factor genes provides a new set of tools that could be used to interrogate gene regulatory networks in pancreatic development and potentially generate greater numbers of beta cells from ES cells.

[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.