MRI Features of Diffuse Glioneuronal Tumor with Oligodendroglioma-like features and Nuclear Clusters: A Case Report and Literature Review.

INTRODUCTION

Accurate diagnosis of diffuse glioneuronal tumors with oligodendroglioma-like features and nuclear clusters (DGONC) remains challenging due to scarce clinical and imaging evidence. Further systematic studies are therefore needed to characterize this tumor entity.

CASE PRESENTATION: A 7-year-old boy presented with a 3-day history of headache and vomiting. Cranial Magnetic Resonance Imaging (MRI) revealed a wellcircumscribed mass in the right temporal lobe with a ground-glass appearance and no contrast enhancement or restricted diffusion. After gross total resection, histopathology showed diffusely infiltrating oligodendroglioma-like cells accompanied by "pennies on a plate" multinucleated cells and nuclear clusters. DNA methylation profiling confirmed the diagnosis of DGONC (calibrated score, 0.99), and chromosomal copy number analysis demonstrated multiple chromosomal gains without monosomy 14. The patient received radiotherapy alone postoperatively and remained clinically stable at the 35.5-month follow-up. This case suggests that the discordance between high-grade histology and an indolent, low-grade radiological appearance is an important clinical feature of DGONC.

CONCLUSION

This case demonstrates that DGONC can present with non-epileptic onset and without monosomy 14. When a brain tumor exhibits characteristic histology yet a low-grade radiological appearance, DGONC should be considered and the diagnosis confirmed by methylation analysis. Treatment decisions must be made cautiously, based on the extent of surgical resection and histological features.