Fibrillary astrocytomas are the most common type of diffuse low grade astrocytoma. Unlike the other variants of diffuse low grade gliomas (e.g. gemistocytic astrocytoma, protoplasmic astrocytoma, oligoastrocytoma) or the focal low grade gliomas (e.g. pilocytic astrocytoma, subependymal giant cell astrocytoma) they are often merely referred to as a low grade glioma. http://radiopaedia.org/articles/fibrillary-astrocytoma
