Dysembryoplastic neuroepithelial tumors (DNTs) are regarded as benign glioneuronal neoplasms because of their excellent outcomes; however, rare DNTs show malignant transformation. We herein described a case of DNT showing malignant transformation. The patient had intractable epilepsy caused by a tumor at 1 year of age and partial resection was performed. After surgery, the residual tumor showed regrowth and surgery was performed again at 4 years of age. The resected tumor showed the typical histological features of DNT, such as specific glioneuronal elements and alveolar structures. Tumor regrowth was detected again at 6 years of age, and the patient underwent gross total resection. Histologically, the tumor was composed of a high-grade glial component mixed with atypical neuronal cells, and the diagnosis of an anaplastic glioneuronal tumor was made. Genetically, DNT and the anaplastic glioneuronal tumor both shared a copy number gain of the tyrosine kinase domain of fibroblast growth factor receptor 1 (FGFR1), as demonstrated by multiplex ligation-dependent probe amplification (MLPA), corresponding to internal tandem duplication (ITD). A frequent FGFR1-ITD in DNT was previously reported. To the best of our knowledge, an identical mutation between primary and transformed DNT has not yet been demonstrated by MLPA.

中文翻译：

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通过FGFR1酪氨酸激酶结构域的共享拷贝数增加，证实了胚胎发育不良性神经上皮肿瘤的恶变。

胚胎发育不良性神经上皮肿瘤（DNT）由于其优异的疗效而被认为是良性神经胶质瘤。然而，罕见的DNT表现出恶变。我们在此描述了显示出恶性转化的DNT的情况。该患者在1岁时因肿瘤引起了顽固性癫痫，并进行了部分切除。手术后，残留的肿瘤显示再生长，并在4岁时再次进行手术。切除的肿瘤表现出DNT的典型组织学特征，例如特定的神经胶质神经元和肺泡结构。在6岁时再次检测到肿瘤再生长，并对患者进行了大体全切除。从组织学上讲，该肿瘤由与非典型神经元细胞混合的高级神经胶质成分组成，并诊断出间变性神经胶质神经胶质瘤。从遗传学上讲，DNT和间变性胶质神经胶质瘤都共享酪氨酸激酶结构域的拷贝数增加成纤维细胞生长因子受体1（FGFR1），如多重连接依赖性探针扩增（MLPA）所示，对应于内部串联重复（ITD）。先前已报道DNT中常见FGFR1- ITD。据我们所知，MLPA尚未证明原发和转化的DNT之间存在相同的突变。