The term "high-grade glioma" (HGG) refers to a histopathologically defined group of clinically aggressive glial neoplasms, which includes: glioblastoma multiforme (GBM), anaplastic astrocytoma (AA), anaplastic oligodendroglioma (AO), anaplastic oligoastrocytoma or "mixed" glioma, gliosarcoma and, possibly, the gemistocytic astrocytoma (GA). High-grade gliomas are the most common primary cerebral neoplasms in adults, with GBM and AA comprising the vast majority of these neoplasms. HGGs share common hallmarks of varying degrees of glial cell differentiation, an extremely poor prognosis for survival beyond 2-3 years, and a diffuse invasive growth pattern into surrounding brain. The designation HGG distinguishes these aggressive gliomas from their "low-grade" glioma (LGG) counterparts that confer median survival times of 6-10 years. Despite their similarities, the HGGs are biologically heterogeneous and differ significantly in their features of differentiation, presumed his-togenesis, treatment responses and prognosis. This heterogeneity must be appreciated when considering management options for a particular patient with a HGG and in the interpretation of clinical trials.
Over the last 25 years, despite a plethora of novel treatment approaches, the prognosis for patients with HGGs has not significantly improved. Limitations imposed by tumor location, intrinsic biological features, and tumor growth patterns complicate the effective management of HGGs. It is now well recognized that HGG is a diffuse disease. While an extensive amount of research has recently targeted the study of HGG cell migration and invasion, we have yet to solve the clinical problem of loco-regional control of HGGs. Ultimately, significant improvement in outcome for HGG patients will require effective loco-regional tumor control, while cure will require novel strategies to address the diffuse invasive component of the tumor. The role of the neurosurgeon in the
Was this article helpful?
The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.