When evaluating supratentorial tumors with mixed high- and low-grade features on magnetic resonance studies, consider the possibility of low-grade tumor de-differentiation, such as in an angiocentric glioma, in addition to high-grade malignancies such as medulloblastomas or anaplastic ependymomas.

From the manuscript

Imaging characteristics of an unusual, high-grade angiocentric glioma: A case report and review of the literature.

Abstract
Angiocentric gliomas have recently been reclassified as a separate central nervous system tumor. Few cases have been reported, and most of those correspond to slow-growing, low-grade neoplasms in very young pediatric patients. Here we describe magnetic resonance imaging findings (including diffusion imaging, spectroscopy and tractography) in an unusual higher-grade neoplasm with pathologic features suggestive of an angiocentric glioma in a 15-year-old male. The tumor had mild heterogeneous enhancement on magnetic resonance imaging, and a low apparent diffusion coefficient (9.9 x 10-4 mm2s-1), consistent with an intermediate-to-high cellularity tumor. Spectroscopic imaging showed elevated choline/phosphocreatine and choline/N-acetyl aspartate ratios, suggesting an unusually aggressive tumor. We conclude that angiocentric glioma should not be excluded from consideration at primary diagnosis, particularly in teenaged patients nearing adulthood.