Rosette-forming glioneuronal tumors (RGNTs) are benign WHO grade 1 tumors that occur in the ventricular system, particularly the fourth ventricle. RGNTs and dysembryoplastic neuroepithelial tumors (DNTs) are both categorized as neuronal and mixed neuronal-glial tumors and may be difficult to distinguish. Coexistence of the two tumor types has been reported. Here, we report a pediatric case of RGNT with DNT-like features showing intraventricular dissemination. The tumor occurred in the medial temporal lobe and presented with specific pathological glioneuronal elements including floating neurons, which are typical in DNTs, but was diagnosed as RGNT because of the presence of neurocytic rosettes. Genetic analysis detected fibroblast growth factor receptor 1 internal tandem duplication (FGFR1-ITD) of the tyrosine kinase domain, which was previously reported to be specific for DNT. RGNTs with FGFR1-ITD may show atypical clinical presentation and pathological features.

玫瑰花结型胶质神经元肿瘤 (RGNT) 是 WHO 1 级良性肿瘤，发生在心室系统，尤其是第四脑室。RGNT 和胚胎发育不良神经上皮肿瘤 (DNT) 均被归类为神经元肿瘤和神经元-神经胶质混合肿瘤，可能难以区分。已有两种肿瘤类型共存的报道。在这里，我们报告了一例具有 DNT 样特征的 RGNT 儿科病例，显示脑室内播散。肿瘤发生在内侧颞叶，表现为特定的病理胶质神经元成分，包括漂浮神经元，这在 DNT 中是典型的，但由于存在神经细胞玫瑰花结而被诊断为 RGNT。遗传分析检测到成纤维细胞生长因子受体 1内部串联重复 ( FGFR1-ITD) 的酪氨酸激酶结构域，之前报道该结构域专用于 DNT。具有FGFR1 -ITD 的 RGNT 可能表现出非典型的临床表现和病理特征。