• Pediatric low grade gliomas (PLGG) which include pilocytic astrocytoma (PA) are the most frequent brain tumors and represent 25-30% of central nervous system tumors in children [ 1 ]. (biomedcentral.com)
  • Astrocytomas Astrocytomas are central nervous system tumors that develop from astrocytes. (msdmanuals.com)
  • Results: For births 1968-2016, paternal exposure from offspring birth to cancer diagnosis was associated with central nervous system tumors (adjusted odds ratio [OR] = 1.30, 95% confidence interval [CI] 1.04-1.63) and germ cell tumors (OR = 1.82, 95% CI 1.05-3.27), while maternal pregnancy exposure was associated with astrocytoma ( OR = 1.89, 95% CI 1.00-3.57). (cdc.gov)
  • These data suggest that TP53 mutations may play a role in astrocytoma development and are predominantly associated with higher grade tumors. (nih.gov)
  • The lowest-grade astrocytomas, which are sometimes known as pilocytic gliomas , have a five-year survival rate of approximately 70 percent, but the outlook for patients with higher-grade tumors is significantly less propitious. (microscopyu.com)
  • DWI might, in theory, effectively distinguish tumor types and histologic grades because higher grade tumors with more densely packed cells should have increasingly restricted diffusion (with a lower ADC). (ajnr.org)
  • Astrocytomas, including the most malignant form, glioblastoma multiforme, are the most frequent and deadly primary tumors of the human nervous system. (nih.gov)
  • Five of the 11 grade III astrocytomas (glioblastoma multiforme), but only one of seven grade II astrocytomas (anaplastic astrocytoma) and none of either the grade I astrocytomas or oligodendrogliomas demonstrated distinct point mutations involving the TP53 gene. (nih.gov)
  • They show an average value of MIB-1 in the three groups of grade II astrocytoma, AA and glioblastoma multiforme (GBM) of approximately 3,12, and 16 respectively. (upmc.edu)
  • Whereas VEGF is up-regulated in only a portion of anaplastic astrocytoma (AA), it is overexpressed in most glioblastoma multiforme (GBM), and the level of expression is correlated with grade of glioma. (northwestern.edu)
  • Glioblastoma multiforme (GBM) is the most common and most malignant of the glial tumors. (medscape.com)
  • To study the possible role of TP53 in astrocytoma development, 24 randomly chosen human astrocytic tumors were examined for genomic TP53 sequence aberrations using primer-directed DNA amplification in conjunction with direct sequencing. (nih.gov)
  • According to the 2007 World Health Organization(WHO) classification of tumors of the central nervous system, the WHO defines diffusely astrocytic tumors with cytological atypia as grade II (diffuse astrocytoma), those also showing anaplasia and mitotic activity as grade III (AA), and tumors additionally showing microvascular proliferation and/or necrosis as WHO grade IV. (upmc.edu)
  • In summary, our data show that ATRX alterations are frequent in adult diffuse gliomas and are specific to astrocytic tumors carrying IDH1/2 and TP53 mutations. (mcmaster.ca)
  • Malignant gliomas are the most aggressive human brain tumors without any curative treatment. (aacrjournals.org)
  • The antitumor effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in gliomas has thus far only been thoroughly established in tumor cell lines. (aacrjournals.org)
  • [ 2 ] and is confined to adult-type diffuse isocitrate dehydrogenase (IDH)-mutant gliomas, including grades 2-4 IDH1 -mutant astrocytoma. (medscape.com)
  • In the present study, MDR1 P-gp was immunodetected by Western blot analysis in 60 human brain tumors, including meningiomas, schwannomas, low-grade gliomas (astrocytomas, pilocytic astrocytomas) and high-grade gliomas (anaplastic astrocytomas, glioblastomas and anaplastic oligodendrogliomas). (nih.gov)
  • Pediatric low-grade gliomas (PLGG) are the most frequent brain tumors in children. (biomedcentral.com)
  • Gliomas are the most common primary brain tumors in children and adults. (mcmaster.ca)
  • Using sequencing and/or immunohistochemical analyses, we investigated ATRX alterations (mutation/loss of expression) and their association with TP53 and IDH1 or IDH2 mutations in 140 adult WHO grade II, III and IV gliomas, 17 pediatric WHO grade II and III astrocytomas and 34 pilocytic astrocytomas. (mcmaster.ca)
  • Functional analysis of HOXD9 in human gliomas and glioma cancer stem cells. (123dok.net)
  • Gliomas, especially glioblastomas (GBMs), are the most malignant primary brain tumors[1]. (123dok.net)
  • Of the estimated 17,000 primary brain tumors diagnosed in the United States each year, approximately 60% are gliomas. (medscape.com)
  • Gliomas are primary tumors that originate in brain parenchyma. (msdmanuals.com)
  • General references Gliomas are primary tumors that originate in brain parenchyma. (msdmanuals.com)
  • Furthermore, transgenic mice harboring the viral-encoded large T-antigen (LT-Ag) alone develop tumors of neuroectodermal origin, including malignant peripheral nerve sheath tumors (MPNSTs) and glioblastomas. (cdc.gov)
  • Using immunohistochemistry, we observed HOXD9 protein expression in human brain tumor tissues, including astrocytomas and glioblastomas. (123dok.net)
  • Anaplastic astrocytomas, in particular, can later evolve into glioblastomas (called secondary glioblastomas). (msdmanuals.com)
  • Both primary and secondary glioblastomas have distinct genetic characteristics, which can change as the tumors evolve. (msdmanuals.com)
  • Raccoon polyomavirus may contribute to the development of malignant brain tumors of raccoons. (cdc.gov)
  • However, these defects fail to explain the incredible heterogeneity and immune suppression observed in malignant brain tumors, two major hurdles to their treatment, which remains mostly palliative. (stanford.edu)
  • They were prevalent in astrocytomas and oligoastrocytomas, but were absent in oligodendrogliomas (p (mcmaster.ca)
  • Like astrocytomas, oligodendrogliomas can evolve into more aggressive forms, such as anaplastic oligodendrogliomas (WHO grade III), which are managed accordingly. (msdmanuals.com)
  • In the present study, we investigated the therapeutic potential of TRAIL in primary human glioma cells. (aacrjournals.org)
  • We established a stable culture model for isolated primary human glioma cells. (aacrjournals.org)
  • In contrast to cell lines, isolated primary tumor cells from all investigated glioma patients were highly TRAIL resistant. (aacrjournals.org)
  • Regardless of the tumor heterogeneity, cotreatment with the proteasome inhibitor bortezomib efficiently sensitized all primary glioma samples for TRAIL-induced apoptosis and tremendously reduced their clonogenic survival. (aacrjournals.org)
  • Astrocytomas are a form of glioma (ie, a neoplasm of the glial cells, which constitute the supportive tissue of the brain and nervous system). (medscape.com)
  • The expression of GFAP is used to distinguish astrocytic neoplasms from epithelial or mesenchymal tumors that may on occasion mimic a glioma [3]. (upmc.edu)
  • Results: In this study, we found high expression of the HOXD9 gene transcript in glioma cell lines and human glioma tissues by quantitative real-time PCR. (123dok.net)
  • Finally, we cultured human glioma cancer stem cells (GCSCs) from patient specimens found with high expression of HOXD9 in GCSCs compared with normal astrocyte cells and neural stem/progenitor cells (NSPCs). (123dok.net)
  • They were absent in the 17 grade II and III astrocytomas in children, and the 34 pilocytic astrocytomas. (mcmaster.ca)
  • She returned to UCSF to conduct translational research, and apply her combined expertise in stem cells and signaling on the study of brain neoplasms and human stem and progenitor cells. (stanford.edu)
  • Pilocytic, other low-grade, or anaplastic astrocytomas tend to develop in younger patients. (msdmanuals.com)
  • Tumor cell hierarchies are poorly understood, providing no explanation for why tumor cells with stem-like, progenitor-like, and differentiated features co-exist and interact with normal brain cells and immune-infiltrating cells within a single tumor entity, and how this heterogeneity relates to the lack of active immune infiltration. (stanford.edu)
  • however, that term is no longer used to refer to a single tumor type but rather to a mixed neoplasm. (msdmanuals.com)
  • Astrocytes are non-excitable cells in the CNS that can cause life-threatening astrocytoma tumors when they transform to cancerous cells. (mdpi.com)
  • This review discusses the similarities and differences between the morphology of astrocytes and astrocytoma cells, and the role that dysregulation in glutamate and calcium signaling plays in the aberrant morphology of astrocytoma cells. (mdpi.com)
  • To explore the possibility that VEGF may act as a driving force in the progression of AA to GBM, the VEGF isoforms VEGF 121 and VEGF 165 were overexpressed in genetically modified, mutant H-Rastransformed human astrocytes that on intracranial implantation form AA-like tumors. (northwestern.edu)
  • The parental mutant H-Ras-modified astrocytes expressed four times more endogenous VEGF than normal human astrocytes, but on intracranial implantation formed hypovascular, hypoxic, small AA-like tumors. (northwestern.edu)
  • Combined alteration of these genes may contribute to drive the neoplastic growth in a major subset of diffuse astrocytomas in adults. (mcmaster.ca)
  • Treatment options in astrocytomas include operative intervention, chemotherapy and radiotherapy, and are guided in part by WHO Classification. (medscape.com)
  • Axial T2-weighted MRI shows a low-grade astrocytoma of the inferior frontal lobe with mild mass effect and no surrounding edema. (medscape.com)
  • In northern California and southern Oregon, we diagnosed 10 cases of olfactory tract/frontal lobe brain tumors in free-ranging raccoons during March 2010-May 2012. (cdc.gov)
  • We isolated primary tumor cells from 13 astrocytoma and oligoastrocytoma patients of all four WHO grades of malignancy and compared the levels of TRAIL-induced apoptosis induction, long-term tumor cell survival, caspase, and caspase target cleavage. (aacrjournals.org)
  • The successful early diagnosis of brain tumors plays a major role in improving the treatment outcomes and thus improving patient survival. (researchgate.net)
  • CAN008 prolongs overall survival in patients with newly diagnosed GBM characterized by high tumor mutational burden. (cdc.gov)
  • These deletions are diagnostic for oligodendroglial tumors, predict longer survival, and predict a better response to radiation therapy and chemotherapy. (msdmanuals.com)
  • Summary: Astrocytoma, or pituicytoma, of the posterior pituitary is a relatively rare entity consisting of poorly characterized glial tumor cells. (ajnr.org)
  • We recently identified frequent alterations in chromatin remodelling pathways including recurrent mutations in H3F3A and mutations in ATRX (α-thalassemia/mental-retardation-syndrome-X-linked) in pediatric and young adult glioblastoma (GBM, WHO grade IV astrocytoma). (mcmaster.ca)
  • Perturbed homeostasis of the neurotransmitter glutamate is associated with astrocytoma tumor onset and progression, but the factors that govern this phenomenon are less known. (mdpi.com)
  • The study showed that the modified high-fat, low-carbohydrate diet increased the life expectancy of the mice by 50% compared with the control group, while also reducing tumor progression by a similar amount. (medscape.com)
  • This mass was resected via a transspenoidal approach, and histology revealed a moderately cellular astrocytomas with compact fibrillated cells in a fascicular pattern. (ajnr.org)
  • Dr. Petritsch is an expert in oligodendrocyte progenitor cells, and cancer stem cells, and her team's emphasis is on intra-tumoral heterogeneity, in vitro and in vivo cancer model development, and tumor-immune interactions. (stanford.edu)
  • We therefore work to gain an understanding of how brain cells control the fate of their progeny, whereby we unravel novel points of vulnerabilities in brain tumor cells, that could be exploited therapeutically. (stanford.edu)
  • It is known that brain tumor cells, on the other hand, defy many general principles of neurobiology. (stanford.edu)
  • Whereas these modest levels of VEGF overexpression were insufficient to drive oxygenation and GBM formation, an additional 8-fold increase in VEGF expression mediated by retroviral infection with constructs encoding either VEGF 121 or VEGF 165 resulted in cells which, after intracranial implantation, formed tumors that were larger, more vascular, and better oxygenated than those formed by the mutant H-ras parental cells. (northwestern.edu)
  • However, the tumors formed by the cells expressing exogenous VEGF 121 or VEGF 165 retained the phenotype of AA, lacking areas of necrosis that are the hallmark of the GBM pheno-type. (northwestern.edu)
  • called either cancer stem cells (CSCs) or tumor-initiat-ing cells[3]. (123dok.net)
  • Rarely, astrocytomas contain astrocytoma and oligodendroglioma cells. (msdmanuals.com)
  • They used human-derived glioblastoma cells in a mouse model. (medscape.com)
  • While some patients can be cured with surgery alone, more than 70% need complimentary treatments due to the location of tumors that preclude resection [ 2 ]. (biomedcentral.com)
  • At a large tertiary referral pediatric hospital, we examined initial pre-resection imaging and pathology reports for all children who had surgical biopsy or resection of a tumor located in the cerebellum and/or fourth ventricle from 2006 to 2009. (ajnr.org)
  • Pre-operative angiography for precise information of the vascularity and displacement of normal vessels should be considered in patients with a diagnosis of brain tumor: in that way, an association of an AVM with a brain tumor could be demonstrated pre-operatively [4]. (upmc.edu)
  • Five different types of pituicytes have been identified on the basis of their cytoplasmic characteristics ( 1 ), and attempts are presently underway to characterize and classify each type as a progenitor of a separate type of neurologic tumor. (ajnr.org)
  • Astrocytomas can be indolent or aggressive, depending on tumor grade, which drives prognosis and clinical decision making. (medscape.com)
  • The prognosis of patients is greatly determined by the grade of the tumor. (microscopyu.com)
  • The current WHO classification of human astrocytomas has limitation in predicting prognosis and diagnosis. (upmc.edu)
  • We report two cases of posterior pituitary astrocytomas in middle-aged women presenting as focal lesions of the neurohypophysis. (ajnr.org)
  • A review of the literature reveals only a few reports of this tumor, and there has been scanty discussion of the imaging findings of posterior pituitary astrocytomas compared with lesions of the anterior pituitary gland. (ajnr.org)
  • This histology was interpreted as consistent with a posterior pituitary astrocytoma. (ajnr.org)
  • DWI reportedly accurately differentiates pediatric posterior fossa tumors, but anecdotal experience suggests limitations. (ajnr.org)
  • 6 - 8 In contrast, there are studies suggesting that DWI may be highly accurate in tumor diagnosis in the pediatric posterior fossa. (ajnr.org)
  • One recent study showed no overlap between ADC values in the 3 main pediatric posterior fossa tumors: medulloblastoma ( n = 8), JPA ( n = 17), and ependymoma ( n = 5). (ajnr.org)
  • The Petritsch lab broadly investigates underlying causes for the intra-tumoral heterogeneity and immune suppression in brain tumors from a developmental neuro-developmental perspective. (stanford.edu)
  • We think that defective cell fate decisions fuel the intra-humoral heterogeneity and plasticity that makes treatment of human brain tumors so challenging. (stanford.edu)
  • [ 1 ] Astrocytomas can arise anywhere in the nervous system, but most commonly occur in the brain. (medscape.com)
  • Thus, although PyV-induced oncogenesis in laboratory animals has been a prolific model for the study of the cell cycle and cell transformation, natural infections rarely result in tumor formation, so the steps in cell transformation after natural infection are being revealed more slowly. (cdc.gov)
  • Most veterinary diagnostic laboratories receive large numbers of raccoon ( Procyon lotor ) carcasses for diagnosis, yet tumors of any type are rarely reported ( 15 - 17 ). (cdc.gov)
  • Classification of astrocytomas is based on distinct histopathologic and molecular alterations, and drives treatment decision making. (medscape.com)
  • The clustering of cases and association of the tumors with the olfactory pathways suggested an infectious cause with a distinct route of transmission and tropism. (cdc.gov)
  • Distinct aneuploid evolution of astrocytoma and glioblastoma during recurrence. (cdc.gov)
  • Computer-aided brain tumor diagnosis from MRI images consists of tumor detection, segmentation, and classification processes. (researchgate.net)
  • Studies reliant on molecular detection of tumor-associated virus in isolation, however extensive, are inconclusive because association between PyVs and naturally occurring neoplasms varies and because PyV infections are highly prevalent, yet tumor formation is rare ( 3 , 4 , 12 - 14 ). (cdc.gov)
  • Simple structural features (macrocystic tumor, location off midline) aided in distinguishing JPA from the other tumors in these cases. (ajnr.org)
  • High-grade tumors are especially difficult to eradicate via surgery, and in some cases surgery may not be recommended at all due to position or widespread invasion of the brain tissues. (microscopyu.com)
  • We have identified a candidate etiologic agent, dubbed raccoon polyomavirus, that was present in the tumor tissue of all affected animals but not in tissues from 20 unaffected animals. (cdc.gov)
  • This region contains a candidate tumor suppressor gene, TP53, which has recently been implicated in the etiology of a broad array of human cancers. (nih.gov)
  • The American Cancer Society estimates that infectious pathogens are associated with up to 20% of all human cancers worldwide. (cdc.gov)
  • Recent molecular genetic analyses of astrocytomas have demonstrated frequent chromosome 17 deletions involving the telomeric region of the short arm (17p12-pter). (nih.gov)
  • Most samples from primary tumors expressed P-gp at the same levels as normal brain tissue except for schwannomas, in which levels were reduced by 65%, and meningiomas, in which levels were more than 10-fold higher in 7 of 10 samples. (nih.gov)
  • These results indicate that the majority of primary brain tumors express MDR1 P-gp and that its high expression levels in meningiomas may be a marker for this type of brain tumor. (nih.gov)
  • The primary treatment for an astrocytoma is generally surgery. (microscopyu.com)
  • McComb RD, Burger PC (1985) Pathologic analysis of primary brain tumors Neurol Clin 3:711-28. (upmc.edu)
  • The primary objective is to determine the objective response rate of trametinib as a single agent for treatment of progressing/refractory tumors with MAPK/ERK pathway activation. (biomedcentral.com)
  • The same pathway is also activated in plexiform neurofibromas (PNs) which are low-grade tumors involving peripheral nerves in patients with neurofibromatosis type 1 (NF1). (biomedcentral.com)
  • During the same period, no other raccoon tumors were reported in diagnostic laboratories across the United States and Canada. (cdc.gov)
  • Tumor genetics are useful for predicting response to adjuvant therapy. (medscape.com)
  • The patient underwent trans-sphenoidal surgery (TSS), with some residual tumor being seen on postoperative imaging. (ajnr.org)
  • A progressive increase in the bulk of the residual tumor was noted on follow-up MR examinations during the next 5 years. (ajnr.org)
  • MRI for follow up showed residual brain tumor over the left lentiform nucleus. (upmc.edu)
  • While low-grade astrocytomas (WHO grades 1-2) uncommonly enhance on MRI, many grade 3-4 astrocytomas enhance with gadolinium contrast agents. (medscape.com)
  • High-grade brain tumors, consistently located in the frontal lobes and olfactory tracts, were detected in 10 raccoons during March 2010-May 2012 in California and Oregon, suggesting an emerging, infectious origin. (cdc.gov)
  • High grade astrocytoma is impressed according to the result of high MIB-1/Ki-67 labeling index and strongly positive reaction with GFAP. (upmc.edu)
  • 1 Unfortunately, it is well-known that overlap between tumor grades and types is generally too great to specifically diagnose individual brain tumors with DWI alone, in adults 2 - 5 or children. (ajnr.org)
  • Our anecdotal experience, from several years of routine DWI in pediatric brain tumors, has been that ADC values have not been as helpful as in these reports. (ajnr.org)
  • Vascular endothelial growth factor (VEGF) is thought to promote tumor growth and angiogenesis. (northwestern.edu)
  • The overlap in ADC between tumor types appeared partly due to technical factors (in small, heterogeneous, calcific, or hemorrhagic tumors) but also likely reflected true histologic variability, given that our 3 overlap cases included a desmoplastic medulloblastoma, an anaplastic ependymoma, and a JPA with restricted diffusion in its nodule. (ajnr.org)
  • of tumor detection, segmentation, and classi fi cation processes. (researchgate.net)
  • Preliminary data have shown that the modified diet appears to make glioblastoma tumors more sensitive to treatment with radiation and chemotherapy. (medscape.com)
  • Tuberous Sclerosis Complex (TSC) Tuberous sclerosis complex is a dominantly inherited genetic disorder in which tumors (usually hamartomas) develop in multiple organs. (msdmanuals.com)