Neuronal and mixed neuronal glial tumors associated to epilepsy. A heterogeneous and related group of tumours

The group of brain tumors with mature components encompasses several pathol ogical entities including: the ganglioneuroma; the gangliocytoma; the gangl ioglioma; the desmoplastic ganglioglioma; the neurocitoma and a group of gl ioneuronal hamartomatous tumorous lesions, such as meningoangiomatosis. The dysembryoplastic neuroepithelial tumor is characterized by the presence of multiple cortical nodules made up of small, oligo-like cells and a myxoid pattern rich in mucopolysaccharides. Mature neuronal cells are frequently d etected throughout the tumor. Most of them are associated with microhamarti as in the adjacent brain and pharmacoresistant epilepsy. The excellent prog nosis of the majority of these tumors and the potential for malignant trans formation of the glial component in the ganglioglioma are the two most rema rkable findings. Histological signs of anaplasia and greater mitotic and pr oliferative activities are associated with local recurrences. Atypical neur ocytomas occur only exceptionally. Treatment choices are surgical resection ing and, in those cases presenting greater proliferative activity and cytol ogical atypia, postoperative radiotherapy may be recommended. This paper reviews this heterogeneous group of neoplasms and hamartomatous lesions, pointing out presumable transitions among the different types of m ixed neuronal and glial brain tumors. A single term of "mixed neuronal-glia l tumors" is defended, distinguishing different subgroups of tumors, depend ing on the predominant cellular component.