Intracranial myxoid mesenchymal tumors harboring EWSR1 fusions with CREB transcriptional factor gene families were recently described in several case reports and a few case series and this tumor closely resembles the myxoid variant of angiomatoid fibrous histiocytoma. We herein present an intracranial mesenchymal myxoid tumor arising in the third ventricle of a middle-aged woman. The tumor displayed prominent myxoid features consisting of mildly atypical oval to round cells, arranged in reticular and cord-like structures, with starburst-like amianthoid fibers, whereas it lacked pseudoangiomatoid spaces, pseudocapsules and lymphoid cuffing. Immunophenotypically, tumor cells were positive for EMA, desmin, and ALK (focal). EWSR1 and CREB1 rearrangements were identified using FISH assay. The proliferation index was low. It is currently uncertain whether these myxoid tumors represent a variant of angiomatoid fibrous histiocytoma or a novel tumor entity.

中文翻译：

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EWSR1-CREB1基因融合的颅内粘膜间质瘤：1例报道并文献复习。

最近在几个病例报告和几个病例系列中描述了带有EWSR1与CREB转录因子基因家族融合的颅内粘液样间充质肿瘤，该肿瘤与类血管瘤样纤维组织细胞瘤的粘液样变体非常相似。我们在此提出了一种在中年妇女的第三脑室中发生的颅内间质粘液样肿瘤。肿瘤表现出明显的类胶质特征，由轻度非典型的卵圆形到圆形细胞组成，排列成网状和索状结构，具有星状类淀粉样纤维，但缺乏假性血管瘤腔，假性胶囊和淋巴囊肿。从免疫表型上看，肿瘤细胞的EMA，结蛋白和ALK（局部）呈阳性。EWSR1和CREB1使用FISH测定法鉴定了重排。增殖指数低。目前尚不清楚这些粘液样肿瘤是否代表血管瘤样纤维组织细胞瘤的变体或新的肿瘤实体。