Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Surgical specimens from 30 patients (13 males and 17 females) with intractable epilepsy with brain tumors and allied lesions were histopathologically examined: 4 of nonneurogenic origin (1 angiolipoma with cortical dysplasia and 3 cavernous hemangiomas), 2 low-grade fibrillary astrocytomas, 1 pleomorphic xanthoastrocytoma, 3 pilocytic astrocytomas with nuclear polymorphism, 1 oligoastrocytoma, 9 gangliogliomas, 3 gangliogliomatous lesions combined with tuberous sclerosis-like dysplastic changes, and 7 undetermined lesions suspected of being mixed glioma, dysembryoplastic neuroectodermal tumor (DNT), or dysplasia. They were all located supratentorially: in the temporal lobe in 21, frontal lobe in 6, and parietooccipital lobe in 3. The age of onset was under 20 years in most patients. Some kinds of dysplasias, such as focal cortical dysplasia, glioneuronal heterotopia, and clustered neurons in the hippocampus and amygdaloid nucleus, were combined in 11 cases, especially those with age of onset under 10 years. Pilocytic astrocytoma-like features were seen in 5 of the gangliogliomas and 3 of the undetermined lesions, and DNT-like features in 2 of the former and 3 of the latter. Gangliogliomas, pilocytic astrocytomas, mixed gliomas, DNTs, and dysplasias may be closely inter-related in the development of intractable epilepsies of young patients.
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PMID:Brain tumors in surgical neuropathology of intractable epilepsies, with special reference to cerebral dysplasias. 987 63

Pilocytic astrocytoma is a central nervous system neoplasia that arises during pediatric age. Only few cases have been documented in patients older than 50 years old. It is a low-grade lesion that can rarely undergo malignant changes presenting the histologic features of a high-grade glioma. We report a case of a pilocytic astrocytoma arising in the eyeball of a 53-year-old man affected by glaucoma that underwent malignant evolution.
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PMID:An unusual case of malignant pilocytic astrocytoma occurring in the eye. 1671 30

Pilocytic astrocytoma is histologically characterized by a biphasic pattern. We report a myxoid form of frontocallosal pilocytic astrocytoma in a 13-year-old girl. MRI showed a relatively well-defined tumor with necrosis and ring-like zone of contrast enhancement. Histological examination showed a monophasic tumor composed of piloid cells on a myxoid background corresponding to a pilomyxoid astrocytoma. This unusual form of pilocytic astrocytoma can be mistaken for a high grade infiltrating glioma. Pilomyxoid astrocytoma is more aggressive than classic pilocytic astrocytoma and has to be distinguished from it.
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PMID:[An unusual and misleading form of pilocytic astrocytoma]. 1679 Nov 25

Pilocytic astrocytoma (PA) is the most common glioma of childhood. Despite their relatively high incidence, the molecular mechanisms responsible for tumorigenesis and growth of PA are poorly understood. Previous in vitro studies in our laboratory showed that despite the absence of ErbB1, PA was sensitive to ErbB1 tyrosine kinase inhibitor gefitinib. To identify alternative targets of gefitinib in PA, we studied other members of the ErbB receptor tyrosine kinase family that have been identified in brain tumors. Using gene expression microarray and Western blot analyses, we found that ErbB3 is highly overexpressed in PA compared with other pediatric brain tumors (glioblastoma, ependymoma, medulloblastoma, atypical teratoid/rhabdoid tumor, and choroid plexus papilloma). Developmental biology studies have identified Sox10 as a regulator of ErbB3 expression during development of the neural crest. Investigation of Sox10 in PA revealed that it is highly overexpressed relative to other pediatric brain tumors, lending support to the theory that Sox10-regulated overexpression of ErbB3 may be driving growth in PA. Sox10-regulated ErbB3 overexpression is a novel insight into the biology of PA, suggests possible recapitulation of developmental pathways in tumorigenesis, and presents possible targets for therapeutic intervention that might be used for hypothalamic variants not amenable to surgical cure.
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PMID:Paired overexpression of ErbB3 and Sox10 in pilocytic astrocytoma. 1689 10

Pilocytic astrocytoma (WHO Grade 1) is a low-grade glioma with a favorable prognosis most commonly diagnosed in patients aged below 20. It is the most common glioma in children, and cases discovered in elderly patients are rare. We report the highly unusual case of an 85-year-old man whose neurological signs included Parkinsonism, and in whom post mortem examination revealed a pilocytic astrocytoma of the brainstem. We also discuss the clinical, neuroradiological and neuropathological differential diagnosis.
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PMID:Pilocytic astrocytoma in the elderly. 1823 98

Pilocytic astrocytoma is a slow-growing, circumscribed glioma that most frequently occurs within the pediatric population. In general, surgical resection for pilocytic astrocytoma is thought to be curative with tumor recurrence or malignant transformation being relatively rare. However, there have been very few studies specifically looking at the prognosis for adult patients diagnosed with pilocytic astrocytoma. To evaluate the frequency of recurrence and malignant transformation of pilocytic astrocytoma in adults, we performed a retrospective analysis of all adult patients who underwent surgical resection for this tumor at our institution over a period of 10 years. In our cohort of 20 patients, there were 6 (30%) recurrences with four patients requiring repeat surgery due to symptomatic progression. Relatively rapid recurrences were noted with the median time to recurrence being 16.5 months. All recurrences occurred within 4 years of initial surgery while patients requiring repeat surgery presented within 17 months of initial surgery. Based on this study estimated rates of freedom from recurrence (FFR) at 12 and 24 months after initial surgery are 94 +/- 5% and 76 +/- 10%, respectively. A high rate of malignant transformation was observed in the patients that underwent repeat surgery with 75% (3/4) progressing to anaplastic astrocytoma on pathological examination. This study provides further evidence that the clinical course of a subset of adult patients with pilocytic astrocytoma will not be benign. The potential for rapid tumor recurrence and malignant transformation necessitates careful post-operative follow-up for adult patients with this tumor.
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PMID:Rapid recurrence and malignant transformation of pilocytic astrocytoma in adult patients. 1953 24

Gliomas are the most common type of paediatric brain tumour and range from benign low grade gliomas which can be resected/observed to aggressive brainstem gliomas with dismal survival rates. Current therapies rely on neurosurgery, radiotherapy, chemotherapy or combination of these conventional modalities and although histopathology helps to direct therapy, molecular pathology has so far not played a major role in the management of paediatric glioma. However, increasing knowledge of glioma biology is starting to impact on drug development towards targeted therapies. Pilocytic astrocytoma, the most common childhood low grade brain tumour, has recently been shown to harbour an activated BRAF/MAPK/ERK pathway in the majority of cases; this represents an attractive target for new agents. The molecular biology of adult malignant glioma is now well described and targeted therapies against VEGFR are already playing a role in the management of glioblastoma. It is likely that high grade gliomas in children and adults share common aberrant molecular pathways but the frequency and mechanisms involved probably will exhibit key differences and on-going comprehensive molecular analyses of paediatric high grade glioma are essential to determine which targets are important in children. However, selection for specific targeted therapy is unlikely to be based on, or restricted by, age but will require individual case by case testing for target presence in order to direct and maximise the efficacy of molecular therapy. Brainstem glioma remains a tumour with a dismal prognosis but relatively little is known about the underlying biology and progress will require a concerted effort to collect tissue by biopsy and autopsy to allow appropriate analysis to identify and validate targets. A new era of molecular based therapies offers the promise of major benefits in the management of paediatric glioma but translating this promise into reality will require further understanding of the biology driving these tumours.
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PMID:Paediatric high and low grade glioma: the impact of tumour biology on current and future therapy. 1963 6

Pilocytic astrocytoma (PA) is the most common glioma in the pediatric population. PAs can exhibit variable behavior that does not always correlate with location, yet at present there is no way to predict which tumors will be more aggressive. To address this problem, an institutional cohort of 147 PAs (118 with outcome data) from both cerebellar and noncerebellar locations (spine, diencephalon, midbrain, brainstem and cortex) was utilized. Parameters included quantification of characteristic morphologic variables as well as genes previously shown to be of relevance in high-grade gliomas, including MIB-1, p53 and MGMT. In this cohort, the classic biphasic appearance was most common in cerebellar tumors, whereas noncerebellar tumors were predominantly microcystic. Associations with outcome suggest that the presence of degenerative atypia may be a favorable factor in PAs. Oligodendroglial morphology and the absence of leptomeningeal invasion are adverse histologic factors, but only in cerebellar tumors. Conversely, MIB-1 proliferation index and p53 and MGMT expression do not correlate with outcome. Morphologic biomarkers thus do exist for PAs, but the utility of each biomarker varies according to location. These results suggest that PAs differ fundamentally according to location; therefore, biological behavior may not simply depend on extent of resection.
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PMID:Impact of morphology, MIB-1, p53 and MGMT on outcome in pilocytic astrocytomas. 1983 38

Pilocytic astrocytoma (PA) is the most common glioma in the pediatric population. PAs can exhibit variable behavior that does not always correlate with location. Although oncogenic rearrangements of the BRAF gene have recently been described in PAs, it is not clear whether such alterations have an impact on outcome. An institutional cohort of 147 PAs (118 with outcome data) from both cerebellar and non-cerebellar locations (spine, diencephalon, midbrain, brainstem, and cortex) was utilized in this study. Parameters included quantification of characteristic morphologic variables as well as genes and molecular loci previously shown to be of relevance in high-grade gliomas, including 1p, 9p, 10q, 17p, 19q, and BRAF. Neither 1p, 9p, and 10q nor 19q showed significant association with outcome in PAs, although p16 deletion was more common in PAs of the midbrain, brainstem, and spinal cord. Loss of heterozygosity on 17p13 correlated with increased risk of recurrence in cerebellar tumors. BRAF gene rearrangements were more common in cerebellar tumors than non-cerebellar tumors and associated with classic biphasic histology in the cerebellum. However, clinical outcome was independent of BRAF status. The molecular biology of PAs differs according to location, yet BRAF rearrangements do not appear to produce PAs with different behavior. Nevertheless, such tumors may have altered sensitivity to pathway-specific adjuvant therapy. Additionally, deletion on 17p13 may be an adverse prognostic biomarker in cerebellar tumors.
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PMID:Association of molecular alterations, including BRAF, with biology and outcome in pilocytic astrocytomas. 2004 55

Pilocytic astrocytoma (PA) is a slow-growing, well-circumscribed grade I glioma generally considered benign, with a low recurrence rate and an excellent prognosis following complete surgical resection. PA is the most common central nervous system glioma in the pediatric population and is rare in adults. We report a 26-year-old male with an intradural extramedullary PA at the thoracolumbar junction following subtotal cerebellar PA resection 18 years previously. Fifteen months after spinal PA resection, the patient is doing well, has regained the ability to stand independently, and has no evidence of any new or enlarging lesions. To our knowledge, this is the longest time reported from initial tumor resection of leptomeningeal dissemination to the distal spinal cord. PA patients with subtotal resection may benefit from continued follow-up for up to 20 years after the initial diagnosis and resection.
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PMID:Spinal seeding of a pilocytic astrocytoma in an adult, initially diagnosed 18 years previously. 2051 44


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