<prompt> Answer this question truthfullyWhat are some types of cortically based intra-axial tumors in white matter that can be occult without IV contrast and what are their characteristics?  <response>: <reason> - Pleomorphic Xanthoastrocytoma PXA - temporal lobe, cyst nodule in 50, enhancement, dural tail, kids 10-20yo, invades leptomeninges, looks like Desmoplastic Infantile Ganglioma but patient is not an infant.- Dysembryoplastic Neuroepithelial Tumor DNET - temporal lobe, high T2 bubbly with bright FLAIR rim, does NOT enhance, hypodense on CT, kids 20 with drug resistant seizures- Oligodendroglioma - ADULT 40-50yo, - enhancement, 90 calcified, frontal lobe, expands the cortex, 1p19q deletion has better prognosis- Ganglioglioma - Any age, - enhancement, NOT bubbly, can look like anything, classic 13yo with seizures cysticsolid mass in temporal lobe with focal calcifications. 