[Papillary glioneuronal tumor with highly degenerative pseudopapillary structure accompanied by specific abortive glial cells: a case report].

Recently, unusual examples of tumors of the mixed glioneuronal type have been reported, including the papillary glioneuronal tumor (PGNT). A 23-year-old woman with a 2-3 months history of headache and insomnia presented with a tumor. Neuroimaging showed a right temporal lobe cystic tumor with a mural nodule enhanced by contrast medium. She underwent gross total resection of the tumor. The tumor was histologically marked by a mixture of glial and neural components. A pseudopapillary component was comprised of highly hyalinized vessels surrounded by a single layer of thin spindle cells stained for glial fibrillary acidic protein. Specific abortive glial cells stained for vimentin/S-100 protein accompanied pseudopapillary structure. Intervening neural areas were occupied by neural cells of varying size, including neurocyte-like cell and ganglionic cells. Ganglionic cells demonstrated abnormal cluster, lack of normal polarity and epiperikaryal immunoreactivity for synaptophysin staining suggesting neural neoplastic nature. No mitotic activity or necrosis was noted. A MIB-1 labeling index was 1.8%. Our patient remains free of disease 33 months after surgical treatment.