Ganglioglioma with anaplastic recurrence of the neuronal element following radiotherapy.

Gangliogliomas are rare tumours in adults representing between 0.5% and 1% of all neuroepithelial tumours. They are of mixed cellularity comprised both of a neuronal and a glial population. Although malignant transformation is rare, and this mostly occurs in the glial element, we present a case of malignant neuroblastomatous transformation of a ganglioglioma. This is only the second ever case to our knowledge in the literature reporting the participation of the neuronal element in the malignant transformation of a ganglioglioma. In contrast with the previous published case, our patient has received post-operative therapeutic radiotherapy. The related literature is reviewed and the oncogenic role of therapeutic irradiation is discussed.