A group of central nervous system neoplasms with a variable amount of neuronal and, less consistently, glial differentiation. They occur at a low frequency and usually carry a favorable prognosis. Representative examples include dysplastic cerebellar gangliocytoma, desmoplastic infantile ganglioglioma, desmoplastic infantile astrocytoma, and dysembryoplastic neuroepithelial tumor. (Adapted from WHO)