Malignant transformation of grade II ganglioglioma to glioblastoma: A case report

Gangliogliomas are well differentiated and slowly growing neuroepithelial tumors composed of neoplastic ganglion cells and neoplastic glial cells corresponding mostly to the World Health Organization grade I tumors. However, some of these tumors disclose histologically more malignant glial component and correspond to grade II or grade III tumors. We report a case of left temporal lobe tumor in a 42-year-old woman fulfilling the diagnostic criteria for atypical (grade II) ganglioglioma with high Ki-67 proliferation index and p53 immunoreactive tumor cells. In spite of gross total removal of the tumor, it recurred eight months after surgery. Histopathological examination of the recurrent tumor revealed that it had undergone malignant transformation into a glioblastoma. This case indicates that gangliogliomas with high Ki-67 proliferating index and p53 immunoreactivity should be carefully monitored for recurrence and malignant progression regardless of their morphological grading and seemingly total surgical removal