Dysembryoplastic Neuroepithelial Tumors: What You Need to Know

• Published in: World neurosurgery Vol. 127; pp. 255 - 265
• Main Authors: Luzzi, Sabino, Elia, Angela, Del Maestro, Mattia, Elbabaa, Samer K., Carnevale, Sergio, Guerrini, Francesco, Caulo, Massimo, Morbini, Patrizia, Galzio, Renato
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2019
• Subjects: Aged; BRAF; Brain neoplasm; Brain Neoplasms - diagnosis; Brain Neoplasms - epidemiology; Brain Neoplasms - genetics; Brain Neoplasms - therapy; Diffusion-weighted MRI; DNET; Drug-resistant epilepsy; Female; Humans; Middle Aged; MR spectroscopy; Neoplasms, Neuroepithelial - diagnosis; Neoplasms, Neuroepithelial - epidemiology; Neoplasms, Neuroepithelial - genetics; Neoplasms, Neuroepithelial - therapy; Neuroepithelial tumor; ADC; MRI; FCD; Neuroepithelial tumor; BRAF; MVNT; Brain neoplasm; IDH; LGG; LKB1; GFAP; CT; NAA/Cho; Drug-resistant epilepsy; Diffusion-weighted MRI; mTOR; DNET; FLAIR; MR spectroscopy; FGFR1
• ISSN: 1878-8750; 1878-8769
• DOI: 10.1016/j.wneu.2019.04.056

An updated and comprehensive review on dysembryoplastic neuroepithelial tumor (DNET) focusing on differential diagnosis, atypical presentation, seizure outcome, and risk of malignant transformation. A PubMed/MEDLINE-based literature search has been performed using “dysembryoplastic neuroepithelial tumor” as a keyword. Two treated cases characterized by an atypical presentation have been reviewed. Of 1162 articles, 200 relevant studies have been selected. DNET is a benign mixed neuronal-glial tumor causing drug-resistant epilepsy primarily in children and young adults. The typical radiological pattern is a magnetic resonance imaging (MRI) T1-hypointense, T2-, and fluid-attenuated inversion-recovery hyperintense multicystic lesion involving the cerebral cortex with no edema. Contrast enhancement may be present and a focal cortical dysplasia is commonly associated with it. MRI diffusion, perfusion, and spectroscopy have a paramount role in the differential diagnosis. The “specific glioneuronal elements” are pathognomonic. They are positive for S100 protein, synaptofisin, neuronal nuclei, oligodendrocyte transcription factor, neurite outgrowth inhibitor, and microtubule-associated protein 2, but negative for glial fibrillary acidic protein. As opposed to v-myb avian myeloblastosis viral oncogene homolog, isocitrate dehydrogenase-1/isocitrate dehydrogenase-2 mutation and codeletion 1p-19q, fibroblast growth factor receptor 1 and BRAF V600E mutations are present. The effectiveness of surgery on seizure outcome has been established. Rare malignant transformations have been reported, especially in extra-temporal and complex forms. Advanced MRI techniques are fundamental in the differential diagnosis for DNET versus other low-grade gliomas. Immuno-phenotype assessment and search for fibroblast growth factor receptor 1 and BRAF V600E mutations limit the risk of misdiagnoses. A gross total tumor removal is generally associated with a seizure-free outcome. Recurrences and malignant transformations may rarely follow, legitimizing MRI surveillance in cases of subtotal tumor resection.