Histopathology, classification, and grading of gliomas

摘要: Neoplastic transformation occurs in all glial cell types of the human nervous system, producing a wide variety clinico-pathological entities and morphological variants. Astrocytomas are most common span an unusually spectrum, ranging from slowly growing juvenile pilocytic astrocytoma to highly malignant glioblastoma multiforme. Diffusely infiltrating astrocytomas cerebral hemispheres show inherent tendency for progression towards more phenotype. This change is morphologically categorized histologic grading schemes (e.g., WHO Grade II IV) associated with sequential acquisition genetic alterations, including mutations p53 homozygous deletions p16 tumour suppressor genes. Loss heterozygosity on chromosomes 10 19q as well amplification EGF receptor largely restricted gliomas thus considered late events progression. Gliomas often phenotypic expression different lineages oligoastrocytoma). Recent studies suggest that occurrence mixed not indicative polyclonal origin but rather reflects altered gene expression, leading balance growth factors influencing glioma differentiation.