O'Brien D F, Farrell M, Delanty N, Traunecker H, Perrin R, Smyth M D, Park T S
Department of Neurosurgery, Epilepsy Surgery Programme, Beaumont Hospital, Dublin, Ireland.
Br J Neurosurg. 2007 Dec;21(6):539-49. doi: 10.1080/02688690701594817.
Dysembryoplastic neuroepithelial tumours (DNETs) were incorporated into the new World Health Organization classification of brain tumours as part of the group of glioneuronal tumours in 1993. Large series of patients with DNETs and pharmaco-resistant epilepsy have been reported. DNETs are most often located in the temporal lobe, occurring in both mesial and lateral temporal locations. DNETs have also been reported in the insular cortex, brain stem, cerebellum, occipital lobe and striatum. Approximately 40% of DNETs are cystic, and solitary nodular, multinodular or diffuse forms have been recognized. Approximately 30% of DNETs are associated with subtle cortical dysplastic changes in the adjacent cortex. DNET nodules usually look like oligodendroglioma, whilst between the nodules it may be possible to recognize vertical columns of neurons surrounded by oligodendrocyte-like cells. Cytologically, oligodendroglial-like cells of DNETs are distinguished from oligodendroglioma by larger nuclei with frequent nuclear indentations and multiple, small nucleoli, whilst oligodendrogliomas consistently show nuclear roundness with one or two occasional nucleoli. Very rare cases of malignant transformation have been reported. DNETs are hypodense on CT and demonstrate decreased signal on the T1-weighted images and a hyper-intense signal on T2-weighted MRI. DNETs associated with pharmaco-resistant epilepsy should be removed early to achieve seizure freedom and prevent tumour progression. The surgical approach should be that of an extended lesionectomy, i.e. excision of the lesion and the abnormal dysplastic cortex around it. Use of MRI-based image guidance (neuronavigation) as a surgical tool to identify this area of abnormal cortex is very helpful to ensure that the extended lesionectomy includes any visibly dysplastic cortex. It is not advocated to use a stereotactic biopsy only, as this may generate an unrepresentative tissue sample consisting of an oligodendroglial component only and may lead to an incorrect diagnosis.
胚胎发育不良性神经上皮肿瘤（DNETs）于1993年被纳入世界卫生组织新的脑肿瘤分类，作为神经胶质神经元肿瘤组的一部分。已有大量关于DNETs和药物难治性癫痫患者的系列报道。DNETs最常位于颞叶，发生于颞叶内侧和外侧。也有DNETs发生于岛叶皮质、脑干、小脑、枕叶和纹状体的报道。约40%的DNETs为囊性，已识别出孤立结节型、多结节型或弥漫型。约30%的DNETs与相邻皮质的细微皮质发育异常改变有关。DNET结节通常看起来像少突胶质细胞瘤，而在结节之间可能识别出被少突胶质细胞样细胞围绕的垂直神经元柱。在细胞学上，DNETs的少突胶质细胞样细胞与少突胶质细胞瘤的区别在于细胞核较大，常有核切迹和多个小核仁，而少突胶质细胞瘤始终表现为核圆形，偶尔有一两个核仁。已报道极罕见的恶性转化病例。DNETs在CT上呈低密度，在T1加权图像上信号降低，在T2加权MRI上呈高信号。与药物难治性癫痫相关的DNETs应尽早切除，以实现无癫痫发作并防止肿瘤进展。手术方法应为扩大病变切除术，即切除病变及其周围异常发育异常的皮质。使用基于MRI的图像引导（神经导航）作为手术工具来识别异常皮质区域，对于确保扩大病变切除术包括任何可见的发育异常皮质非常有帮助。不主张仅使用立体定向活检，因为这可能产生仅由少突胶质细胞成分组成的无代表性组织样本，并可能导致错误诊断。
