The role of postoperative radiotherapy for the treatment of gangliogliomas

Abstract

We read the article by Rades et al1 and we think there was a serious pathologic misinterpretation with these tumors. The authors included desmoplastic infantile gangliogliomas (DIGs) as part of the ganglioglioma category, when in fact they are very different entities from the epidemiological point of view in terms of clinical presentation, histology, and course of treatment. Gangliogliomas account for 1% to 7.6% of all brain tumors, with the higher percentage noted in the pediatric group.2 On light microscopy, both neuronal and astrocytic components are readily apparent. Astrocytic cells are confirmed by a positive chemical reaction to antiserum for glial fibrillary acidic protein (GFAP) and neoplastic ganglion cells demonstrate intense immunoreactivity for synaptophysin. These tumors are classified as either World Health Organization (WHO) grade I or II.2 Tumors with evidence of malignant transformation are anaplastic gangliogliomas (WHO grade III), not desmoplastic gangliogliomas. DIGs representing <1% of all intracranial tumors and are unusual in patients aged >6 years.3 The typical appearance of a DIG is a large cystic lesion with a solid mass located within the frontal and/or parietal lobes. Approximately 100 cases of DIGs have been described in the literature since its first description,4 and the median age at diagnosis is reported to be 5 to 6 months (range, 1-60 months). Noninfantile variants of this biologically benign intracranial neoplasm are rare. DIG has 2 distinct components: a solid component with intense desmoplasia that is always located close to the meninges and a cystic component, which is dominant and an integral part of the tumor. The common pathological features include intense desmoplasia containing GFAP-positive astrocytes and neuronal elements. DIGs are classified as benign WHO grade I tumors of infancy. Complete surgical resection has been possible in approximately 70% of all reported cases. However, in cases with incomplete surgical resection, a second surgery should be considered to be the treatment of choice. Miguel Gelebert-Gonzalez MD*, Ramon Serramito-Garcia MD*, * Department of Surgery, University of Santiago de Compostela, Santiago de Compostela, Spain.