RESUMO
Pilocytic astrocytomas are the primary tumors most frequently found in children and adolescents, accounting for approximately 15.6% of all brain tumors and 5.4% of all gliomas. They are mostly found in infratentorial structures such as the cerebellum and in midline cerebral structures such as the optic nerve, hypothalamus, and brain stem. The present study aimed to list the main characteristics about this tumor, to better understand the diagnosis and treatment of these patients, and was conducted on search of the published studies available in NCBI, PubMed, MEDLINE, Scielo, and Google Scholar. It was possible to define the main histologic findings observed in these cases, such as mitoses, necrosis, and Rosenthal fibers. We described the locations usually most affected by tumor development, and this was associated with the most frequent clinical features. The comparison between the molecular diagnostic methods showed great use of fluorescent in situ hybridization, polymerase chain reaction (PCR), and reverse transcriptase-PCR, important techniques for the detection of BRAF V600E mutation and BRAF-KIAA1549 fusion, characteristic molecular alterations in pilocytic astrocytomas.
Assuntos
Astrocitoma/diagnóstico , Neoplasias Encefálicas/diagnóstico , Hibridização in Situ Fluorescente/métodos , Reação em Cadeia da Polimerase/métodos , Astrocitoma/fisiopatologia , Astrocitoma/terapia , Neoplasias Encefálicas/fisiopatologia , Neoplasias Encefálicas/terapia , HumanosRESUMO
La neurofibromatosis (NF) comprende un grupo de enfermedades genéticas de herencia autosómica dominante, que se clasifican de la siguiente manera: neurofibromatosis tipo 1 (NF1), neurofibromatosis tipo 2 (NF2) y schwannomatosis (también conocida como neurofibromatosis tipo 3). Esta última es una enfermedad muy infrecuente, con una prevalencia aproximada de 1/126 000 personas, por lo que solo profundizaremos las dos primeras. La NF1, también conocida como la enfermedad de Von Recklinghausen, es la más frecuente de las tres y afecta principalmente la piel y el sistema nervioso periférico. Se caracteriza por la presencia de máculas "café con leche", pecas axilares o inguinales, nódulos de Lisch (hamartomas en el iris) y neurofibromas (tumores de la vaina de nervios periféricos). Otras manifestaciones menos frecuentes, aunque de mayor gravedad, incluyen gliomas del nervio óptico, meningiomas, neurofibromas malignos, escoliosis y displasia de la tibia. Su diagnóstico se suele realizar al nacimiento o durante los primeros años de vida, y se estima que un 50% de quienes la padecen presenta dificultades cognitivas. No hay datos concluyentes sobre la mortalidad en los pacientes con NF1, aunque se sabe que la expectativa de vida es menor que en la población general. La NF2 tiene una prevalencia considerablemente menor que la NF1 y su inicio es más tardío, afectando principalmente a adultos jóvenes. La presentación clínica típica se caracteriza por acúfenos, hipoacusia y ataxia en contexto de la presencia de schwannomas vestibulares bilaterales. Otros hallazgos menos frecuentes incluyen schwannomas de nervios periféricos, meningiomas, ependimomas o astrocitomas. La esperanza de vida es de unos 36 años, con una supervivencia media desde el momento del diagnóstico de 15 años. (AU)
Neurofibromatosis (NF) includes a group of genetic diseases with an autosomal-dominant inheritance pattern, and they are classified as follows: Neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2) and Schwannomatosis (also known as neurofibromatosis type 3). This last one is a very rare disease, with an approximate prevalence of 1/126000, so we will only deepen in the first two. NF1, also known as von Recklinghausen disease, is the most frequent, and mainly affects the skin and peripheral nervous system. Its typical manifestations are the presence of café-au-lait macules, axillary or inguinal freckles, Lisch nodules (hamartomas in the iris) and neurofibromas (peripheral nerve sheath tumors). Less frequent manifestations, although more serious, include optic nerve gliomas, meningiomas, malignant neurofibromas, scoliosis and tibial dysplasia. The diagnosis is usually made at birth or during the first years of life, and approximately 50% of patients present cognitive difficulties. There is no conclusive data on mortality in patients with NF1, although it is known that life expectancy is lower than in general population. NF2 has a considerably lower prevalence than NF1, and its onset is later in life, mainly affecting young adults. Its typical clinical presentation is characterized by tinnitus, hearing loss and ataxia in the context in the presence of bilateral vestibular schwannomas. Less frequent findings include peripheral nerve schwannomas, meningiomas, ependymomas or astrocytomas. Life expectancy is about 36 years old, with a median survival from the moment of diagnosis of 15 years. (AU)
Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Lactente , Adulto , Adulto Jovem , Neurofibromatose 2/etiologia , Neurofibromatose 1/etiologia , Neurofibromatoses/classificação , Astrocitoma/fisiopatologia , Ataxia , Escoliose/fisiopatologia , Tíbia/anormalidades , Zumbido , Doenças do Desenvolvimento Ósseo/fisiopatologia , Neuroma Acústico/complicações , Expectativa de Vida , Neurofibromatose 2/epidemiologia , Neurofibromatose 1/fisiopatologia , Neurofibromatose 1/mortalidade , Neurofibromatose 1/epidemiologia , Neurofibromatoses/diagnóstico , Glioma do Nervo Óptico/fisiopatologia , Ependimoma/fisiopatologia , Perda Auditiva , Doenças da Íris/fisiopatologia , Melanose/fisiopatologia , Meningioma/fisiopatologia , Neurilemoma/etiologia , Neurilemoma/fisiopatologia , Neurofibroma/fisiopatologia , Neurofibroma/patologiaRESUMO
OBJECTIVE: To compare cerebral perfusion and diffusion in survivors of childhood posterior fossa brain tumor with neurologically normal controls and correlate differences with cognitive dysfunction. STUDY DESIGN: We analyzed retrospectively arterial spin-labeled cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) in 21 patients with medulloblastoma (MB), 18 patients with pilocytic astrocytoma (PA), and 64 neurologically normal children. We generated ANCOVA models to evaluate treatment effects on the cerebral cortex, thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala, nucleus accumbens, and cerebral white matter at time points an average of 5.7 years after original diagnosis. A retrospective review of patient charts identified 12 patients with neurocognitive data and in whom the relationship between IQ and magnetic resonance imaging variables was assessed for each brain structure. RESULTS: Patients with MB (all treated with surgery, chemotherapy, and radiation) had significantly lower global CBF relative to controls (10%-23% lower, varying by anatomic region, all adjusted P?
Assuntos
Encéfalo/patologia , Circulação Cerebrovascular/fisiologia , Neoplasias Infratentoriais/fisiopatologia , Adolescente , Astrocitoma/fisiopatologia , Astrocitoma/terapia , Encéfalo/diagnóstico por imagem , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Neoplasias Infratentoriais/terapia , Imageamento por Ressonância Magnética , Masculino , Meduloblastoma/fisiopatologia , Meduloblastoma/terapia , Testes Neuropsicológicos , Fluxo Sanguíneo Regional/fisiologia , Estudos Retrospectivos , Adulto JovemRESUMO
Estradiol (E2) regulates several cellular functions through the interaction with estrogen receptor subtypes, ERα and ERß, which present different functional and regulation properties. ER subtypes have been identified in human astrocytomas, the most common and aggressive primary brain tumors. We studied the role of ER subtypes in cell growth of two human astrocytoma cell lines derived from tumors of different evolution grades: U373 and D54 (grades III and IV, respectively). E2 significantly increased the number of cells in both lines and the co-administration with an ER antagonist (ICI 182, 780) significantly blocked E2 effects. ERα was the predominant subtype in both cell lines. E2 and ICI 182, 780 down-regulated ERα expression. The number of U373 and D54 cells significantly increased after PPT (ERα agonist) treatment but not after DPN (ERß agonist) one. To determine the role of SRC-1 and SRC-3 coactivators in ERα induced cell growth, we silenced them with RNA interference. Coactivator silencing blocked the increase in cell number induced by PPT. The content of proteins involved in proliferation and metastasis was also determined after PPT treatment. Western blot analysis showed that in U373 cells the content of PR isoforms (PR-A and PR-B), EGFR, VEGF and cyclin D1 increased after PPT treatment while in D54 cells only the content of EGFR was increased. Our results demonstrate that E2 induces cell growth of human astrocytoma cell lines through ERα and its interaction with SRC-1 and SRC-3 and also suggest differential roles of ERα on cell growth depending on astrocytoma grade.
Assuntos
Astrocitoma/fisiopatologia , Neoplasias Encefálicas/fisiopatologia , Linhagem Celular Tumoral , Estradiol/farmacologia , Receptor alfa de Estrogênio/metabolismo , Coativador 1 de Receptor Nuclear/metabolismo , Coativador 3 de Receptor Nuclear/metabolismo , Astrocitoma/patologia , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/fisiologia , Ciclina D1/genética , Ciclina D1/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Receptor alfa de Estrogênio/genética , Humanos , Coativador 1 de Receptor Nuclear/genética , Coativador 3 de Receptor Nuclear/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Interferência de RNA , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular/genética , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Cerebellum astrocytomas are the most typical nervous system tumors in children. Several cognitive deficits have been previously described. These deficits are probably produced by cerebellar connection and gray matter damage. The present study examines attentional deficits in children operated on for cerebellum astrocytomas, using an attentional paradigm with theoretical and clinical bases: the Attentional Network Test (ANT). This test was designed considering the attentional network theory proposed by Posner, and its usefulness has been demonstrated in clinical settings. Children operated on for cerebellar astrocytoma showed a mild attentional deficit in the orientation network.
Assuntos
Astrocitoma/psicologia , Atenção/fisiologia , Neoplasias Cerebelares/psicologia , Cerebelo/fisiopatologia , Rede Nervosa/fisiopatologia , Orientação/fisiologia , Comportamento Espacial/fisiologia , Astrocitoma/complicações , Astrocitoma/fisiopatologia , Astrocitoma/cirurgia , Mapeamento Encefálico , Neoplasias Cerebelares/complicações , Neoplasias Cerebelares/fisiopatologia , Neoplasias Cerebelares/cirurgia , Criança , Sinais (Psicologia) , Feminino , Fixação Ocular/fisiologia , Lobo Frontal/fisiopatologia , Humanos , Deficiências da Aprendizagem/etiologia , Deficiências da Aprendizagem/fisiopatologia , Masculino , Testes Neuropsicológicos , Lobo Parietal/fisiopatologia , Mascaramento Perceptivo/fisiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/fisiopatologia , Desempenho PsicomotorRESUMO
INTRODUCTION: Use of the electrocorticogram (EcoG) in planning lesionectomies is a controversial subject at present. MATERIAL AND METHODS: We describe a series of 5 patients with epileptic crises, 3 with arteriovenous malformations in whom the lesion was completely resected, followed by postoperative angiography, and two with gliomas with low grade malignancy in whom iridium 192 was implanted. RESULTS: 1. The most frequent reason for consultation was convulsions. 2. In our series of patients the commonest site was the frontal zone of the right hemisphere. 3. Potentials with epileptiform characteristics were registered at the edges of the lesions and occasionally over the lesion itself. In two cases electro-clinical crises were seen. 4. The lesions were resected from normal tissue independently of the EcoG results. CONCLUSION: Although they are preliminary findings, the results of the study support the usefulness of this technique to guide the surgical procedures used for the treatment of intractable epilepsy.
Assuntos
Astrocitoma/cirurgia , Neoplasias Encefálicas/cirurgia , Craniotomia , Eletroencefalografia , Epilepsia do Lobo Frontal/fisiopatologia , Lobo Frontal/cirurgia , Malformações Arteriovenosas Intracranianas/cirurgia , Adolescente , Adulto , Astrocitoma/complicações , Astrocitoma/fisiopatologia , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/fisiopatologia , Epilepsia do Lobo Frontal/etiologia , Feminino , Lobo Frontal/fisiopatologia , Humanos , Malformações Arteriovenosas Intracranianas/complicações , Malformações Arteriovenosas Intracranianas/fisiopatologia , Masculino , Pessoa de Meia-Idade , Lobo Parietal/fisiopatologia , Lobo Parietal/cirurgia , Cuidados Pré-OperatóriosRESUMO
Se realiza un estudio retrospectivo de 63 neoplasias del sistema nervioso, procesadas en el servicio de Patologia del Hospital de Clincas de La Paz, en un periodo comprendido entre enero de 1987 a diciembre de 1992. La localizacion mas frecuente fue cerebro con 33.3 por ciento La edad de mayor incidencia fue entre los 31 a 40 años en un 28 por ciento en sexo masculino tuvo mayor porcentaje 65.1 por ciento y los tumores mas freucnets fueron los neurofibromas con un 23 por ciento los meningiomas con un 19 por ciento y retinoblastomas 17.4 por ciento .
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Sistema Nervoso Central/fisiopatologia , Retinoblastoma/fisiopatologia , Astrocitoma/fisiopatologia , Neoplasias Encefálicas/fisiopatologia , Adenoma/fisiopatologia , Neoplasias do Sistema Nervoso Central/fisiopatologia , Meningioma/fisiopatologiaRESUMO
This is a report on a patient with intractable 'primary' generalized seizures and typical spike-wave EEG patterns, in whom an unexpected temporal lobe astrocytoma was detected by MRI studies. Clinical and electrophysiological studies were performed before and after surgical excision of the tumor and apical temporal lobectomy in an attempt to determine whether 'primary' generalized seizures and EEG patterns and the temporal lobe tumor were only coincident neurological disorders or were indeed related. Before resection, the patient consistently showed a typical spike-wave EEG pattern with no background and paroxysmal activities suggestive of 'secondary' bilateral synchrony in 10 consecutive conventional EEG recordings; neither spontaneous interictal nor ictal ECoG activities suggested focal temporal lobe epileptogenesis. After resection, the patient showed increased pentylenetetrazol (PTZ) convulsive threshold, and reduction in the number of 'primary' generalized seizures, although typical spike-wave EEG discharges persisted. These observations suggest that 'primary' generalized seizures, EEG patterns and the temporal tumor were physiopathologically interrelated, and that both reticulocortical and corticoreticular mechanisms may participate together in the genesis of 'primary' generalized clinical and EEG activities.
Assuntos
Astrocitoma/fisiopatologia , Neoplasias Encefálicas/fisiopatologia , Epilepsia Generalizada/fisiopatologia , Lobo Temporal/fisiopatologia , Adulto , Astrocitoma/cirurgia , Neoplasias Encefálicas/cirurgia , Eletroencefalografia , Seguimentos , Humanos , Imageamento por Ressonância Magnética , MasculinoRESUMO
We report two patients with posterior fossa neoplasms who demonstrated asymmetrically impaired horizontal ocular pursuit documented with electrooculography. One patient had impaired pursuit contralateral to a pontomedullary lesion, whereas the second patient had impaired pursuit ipsilateral to a pontocerebellar lesion. These patients demonstrate that posterior fossa lesions may impair ocular pursuit either contralaterally or ipsilaterally unlike cerebral hemispheric lesions, which impair ocular pursuit ipsilaterally or bilaterally.