Glioneuronal and Neuronal Tumors: Who? When? Where? An Update Based on the 2021 World Health Organization Classification

Abstract

Neuronal and glioneuronal tumors usually have a benign course and may have typical imaging characteristics, allowing their diagnosis based on MR imaging findings. The most common lesions are dysembryoplastic neuroepithelial tumors and gangliogliomas, which have typical imaging characteristics. The fifth edition of theWorld Health Organization Classification of Tumors of the Central Nervous System, recently published in 2021, places greater emphasis on molecular markers to classify tumors of the CNS, leading to extensive changes in the classification of tumors, including neuronal and glioneuronal tumors. The 2021 revision included 3 new tumors types: multinodular and vacuolating neuronal tumor, diffuse glioneuronal tumor with oligodendroglioma-like features and nuclear clusters (a provisional type), and myxoid glioneuronal tumor. Following these recent changes in the World Health Organization classification, we aimed to review the main imaging features of these lesions in relation to their histopathologic and molecular features.Learning Objectives: To list the neuronal and glioneuronal tumors; recognize the main imaging findings and histologic characteristics of neuronal and glioneuronal tumors; know the typical location of each neuronal and glioneuronal tumor; and become familiar with the main molecular alterations of neuronal and glioneuronal tumors to better understand their behavior