Epilepsy due to a temporal ganglioglioma and its subsequent malignant transformation into a primitive neuroectodermal tumor

BACKGROUND: Gangliogliomas (GGs) are rare brain tumors, and their malignant changes are still less frequent. In these cases, almost always the malignant component is the glial one. However, there are few cases in which the neuronal component exhibits malignant transformation. CASE DESCRIPTION: We described a case of a 14-year-old male patient who started with seizures and 5 years later, its frequency was almost daily despite being treated with several antiepileptic drugs. Magnetic resonance imaging showed a nonenhancing lesion located at the right inferior temporal gyri. He underwent surgery, and the tumor was completely removed. Histological diagnosis was GG. He had no seizures anymore, but 3 years later, the tumor recurred as a giant heterogeneously enhancing space-occupying mass within the right temporal lobe. A second surgical resection was performed. Histological diagnosis was a primitive neuroectodermal tumor (PNET). One month and a half later, the tumor has recurred again. He and his family decided not to undergo another operation, so he was referred to the radiotherapy department. CONCLUSION: As in this patient, GGs may recur as a primitive neuroectodermal tumor, likely because both types of neoplasm form part of the same heterogeneous group of brain tumors which contains neuronal components, but on the other side of the malignancy spectrum.