JAOCR at the Viewbox: Polymorphous Low-Grade Neuroepithelial Tumor of the Young

Polymorphous Low-Grade Neuroepithelial Tumor of the Young

A 12-year-old girl presented with new onset of seizures. The initial noncontrast head CT (A) demonstrated a right parietal mass with heavy calcification and cystic components. MRI revealed a well-defined mass with peripheral cysts demonstrating heterogenous signal on T2/FLAIR imaging (B, C) and no significant enhancement on postcontrast T1-weighted imaging (D). The lesion was resected and found to be a polymorphous low-grade neuroepithelial tumor of the young (PLNTY) on pathology.

First described in 2017, PLNTY is a rare tumor of the pediatric and young adult population. It is considered a subtype of low-grade neuroepithelial tumors that are typically associated with refractory epilepsy, such as gangliogliomas, dysembryoplastic neuroepithelial tumors (DNET), pleomorphic xanthoastrocytoma (PXA), and angiocentric gliomas. PLNTY usually occurs in the temporal lobe although instances have been reported within the parietal, frontal and occipital lobes.¹ On imaging, it is characteristically well-circumscribed with heterogenous signal on MR, macroscopic central calcification on CT, peripheral cystic components, and minimal to no enhancement.² PLNTY has not yet been classified by the World Health Organization, but clinically behaves like a WHO grade I tumor.¹

References

1. Benson JC, Summerfield D, Carr C, et al. Polymorphous low-grade neuroepithelial tumor of the young as a partially calcified intra-axial mass in an adult. Am J Neuroradiol 2020;41(4):573–578.
2. Johnson DR, Giannini C, Jenkins RB, Kim DK, Kaufmann TJ. Plenty of calcification: imaging characterization of polymorphous low-grade neuroepithelial tumor of the young. Neuroradiology 2019;61(11):1327–1332.