Fronto-mesial WHO grade II and III gliomas: specific aspects of tumours arising from the anterior cingulate gyrus.

A total 17 fronto-mesial grade II and III gliomas among a total of 64 frontal grade II and III gliomas underwent surgical resection between January 2003 and June 2007. Eleven fronto-mesial gliomas originated from the anterior cingulate gyrus, while the others originated from the genu of the corpus callosum. None of the grade II or III gliomas originated from the gyrus rectus. Anterior cingulate gliomas exhibited distinct features with regard to presenting symptoms, MRI, histopathology and prognosis. Epilepsy was the dominant presenting symptom of anterior cingulate tumours. Five of the 11 gliomas had a sharp border on MRI. Four of the 11 were histopathologically classified as WHO grade II and seven as WHO grade III and an oligodendrocytic component was apparent in eight of the 11 specimens. Comparison of the post-operative survival with the entire set of frontal gliomas showed a trend that anterior cingulate tumours had a more favourable prognosis.