Papillary Glioneuronal Tumor: Radiological Evidence of a Newly Established Tumor Entity

OBJECTIVE Papillary glioneuronal tumor (PGNT) was newly classified as a Grade I neuronal-glial tumor by 2007 revision of the World Health Organization (WHO) classification of tumor of central nervous system (CNS) because of its characteristic pseudopapillae and diphase differentiation features. Previous literature has laid particular emphasis on pathology manifestations, and radiological features were only briefly mentioned. The purpose of this study was to describe magnetic resonance imaging (MRI) features through reporting 2 cases of PGNT and literature review. METHODS MRI findings and pathology features in 2 cases of PGNT were reported and the literature was reviewed. RESULTS Both patients were confirmed as PGNT by surgery and pathology. Seizure was the main clinical manifestation. Histopathological examination revealed characteristic pseudopapillary structure with astrocytes and neurons. Both lesions were located in the temporal lobe, and one case was closely related with the lateral ventricle. MRI showed cystic-solid mass or cystic lesion with mural nodule. The solid component enhanced strikingly after contrast agent administration. CONCLUSIONS MRI findings of PGNT present certain characteristics. Most cases showed cystic mass with mural nodule and periventricular location was common. Although radiological findings can provide some evidence for this newly established tumor entity, differential diagnosis is still needed.