Bilateral non-contiguous atypical papillary glioneuronal tumor: case report

Papillary glioneuronal tumor (PGNT) was first described as a distinct clinic-pathological entity by Komori et al. in 1998. Since then it has been included as a mixed neuronal-glial tumor in the revised WHO (2007) classification of central nervous system tumors. On brain imaging, it appears as a demarcated, solid to cystic, contrast-enhancing mass usually located in the temporal lobe. Histologically, it is considered a biphasic tumor characterized by small cuboidal GFAP-positive astrocytes around hyalinised blood vessels and synaptophysin-positive interpapillary collections of neurocytes, large neurons and intermediate-sized "ganglioid cells". Although they are generally regarded as benign WHO Grade I tumors, recent reports have described more pathologically aggressive features. To date, these reports have all been single lesions.