Papillary glioneuronal tumor with a high proliferative component and minigemistocytes in a child

Papillary glioneuronal tumor (PGNT) is a rare type of primary brain tumor. Although PGNT has traditionally been defined as a clinically indolent neoplasm, several cases with high proliferative activity and tumor recurrence have recently been reported. We report a case of PGNT in a 12-year-old boy who presented with epilepsy and harbored a 64 mm cystic tumor with a high proliferative component in the right temporal lobe. (11) C-methionine positron emission tomography (PET) showed high uptake in the solid mass. Gross total resection of the tumor mass was achieved and the patient became seizure-free without any neurological deficits. Histologically, the tumor contained two distinct areas of a vasocentric papilliform structure and a desmoplastic component. Minigemistocytic cells and small necrotic regions were observed adjacent to the pseudopapillae. Immunohistochemical analyses revealed both glial and neuronal differentiation. The Ki-67 proliferation index was high (14%) in the area corresponding to the high uptake region in the (11) C-methionine PET. No tumor recurrence was observed 20 months after surgery. High proliferative PGNTs are rare and to our knowledge this is only the third pediatric case of PGNT with atypical features reported in the literature. Hence, we here review the reported cases of PGNT and discuss the clinical, radiological and histological features of this malignancy.