Low Grade Astrocytomas
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چکیده
Astrocytomas are tumors that are believed to arise from precursors of astrocytes – supportive cells of the brain named for their star-like shape. Astrocytomas are the most common of the primary brain tumors. The pathologist, using a microscope, grades these tumors on a scale of I to IV based on how quickly the cells are reproducing, as well as their potential to invade nearby tissue. Grade IV astrocytomas, also called glioblastoma, are the most aggressive of the astrocytomas. Glioblastoma cells reproduce rapidly. Grade III astrocytomas, also known as anaplastic astrocytomas, reproduce at an intermediate rate. Grades I and II astrocytomas are the slowest growing tumors, and are also called low-grade astrocytomas. This article reviews new developments in our understanding and treatment of low-grade astrocytomas.
منابع مشابه
Rapid malignant transformation of low-grade astrocytomas: report of 2 cases and review of the literature.
BACKGROUND Low-grade gliomas have been documented to undergo transformation into high-grade astrocytomas, and the time interval of this transformation has been reported to generally occur within 5 years in about 50% of patients harboring these low-grade lesions. Several studies have investigated the evolution of low-grade gliomas into malignant gliomas by CT and MRI characteristics, but many ha...
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BACKGROUND AND PURPOSE Histopathologic grade of glial tumors is inversely correlated with the minimum apparent diffusion coefficient (ADC). We assessed the diagnostic values of minimum ADC for preoperative grading of supratentorial astrocytomas that were diagnosed as low-grade astrocytomas on conventional MR imaging. MATERIALS AND METHODS Among 118 patients with astrocytomas (WHO grades II-IV...
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AIMS Tenascin-C (TN-C) is an extracellular matrix brain glycoprotein for which conflicting in vitro and in vivo results are reported in the literature dealing with its involvement in astrocytoma aggressiveness, in particular astrocytoma invasion. In view of these conflicting results and the lack of data available on low-grade astrocytomas, the present study focuses on pilocytic World Health Org...
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Pilocytic astrocytoma (WHO grade I) is a circumscribed, slowly growing, benign astrocytoma that most frequently develops in the cerebellar hemispheres and in midline structures and occurs predominantly in childhood and adolescence. In contrast to diffusely infiltrating gliomas in adults (e.g. grade II astrocytomas, oligodendrogliomas), survival of patients with pilocytic astrocytoma is excellen...
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BACKGROUND AND PURPOSE The differentiation of pilocytic astrocytomas and high-grade astrocytomas is sometimes difficult. There are limited comparisons in the literature of the advanced MR imaging findings of pilocytic astrocytomas versus high-grade astrocytomas. The purpose of this study was to assess the MR imaging, PWI, DWI, and MR spectroscopy characteristics of pilocytic astrocytomas compar...
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