MONDO_0021637 (low grade glioma) is a grade I or grade II glioma arising from the central nervous system. This category includes pilocytic astrocytoma, diffuse astrocytoma, subependymal giant cell astrocytoma, ependymoma, oligodendroglioma, oligoastrocytoma, and angiocentric glioma. Also known as: benign glioma, glioma, benign, low-grade glioma.