Anaplastic ganglioglioma with malignant features in both neuronal and glial components--case report.

A 34-year-old man presented with a case of anaplastic ganglioglioma with malignant features in both neuronal and glial components manifesting as seizure episodes over 11 months. The tumor was subtotally removed, followed by irradiation and chemotherapy. The histological diagnosis was anaplastic ganglioglioma. Atypical cells were morphologically estimated as glial and neuronal cells. Though these cells were weakly positive for synaptophysin and glial fibrillary acidic protein, the neural stem cell marker nestin was extremely expressed in both these cells. The MIB-1 index was 15%. Two months later, the tumor recurred with more pleomorphic appearance and higher cellularity with increased nestin expression level. Mitotic cells and multinucleated cells were found in the neuronal components. Cytological examination found dissemination to the leptomeningeal space. The patient died 6 months after the first surgery. This rare case of anaplastic ganglioglioma with both neuronal and glial components, which were extremely positive for nestin, showed progressive worsening of the clinical course. The expression of nestin may suggest that the origin or malignant transformation in anaplastic gangliogliomas is related to the undifferentiated neural stem cells.