Low-grade astrocytomas

Abstract

Glial tumors constitute approximately 50% of newly diagnosed primary brain tumors, with low-grade gliomas (LGG) accounting for approximately 15% of all brain tumors in adults [21]. The subset of tumors classified as LGG represents a heterogeneous group of tumors with astrocytic, oligodendroglial, ependymal, or mixed cellular histologies. In the adult population, the term LGG typically refers to the diffuse, infiltrating variety of tumors classified as World Health Organization (WHO) grade II lesions-specifically low-grade astrocytomas, oligodendrogliomas, or mixed oligoastrocytomas [33]. Among low-grade astrocytomas, the most common his-tologic subtypes are the fibrillary, protoplasmic, and gemistocytic variants. There is no indication in the literature that LGGs are more prevalent in a specific ethnic or national group. © 2010 Springer-Verlag Berlin Heidelberg.