Myxoid mesenchymal tumours harbouring fusions between EWSR1 and the CREB family transcription factors have recently been described. Whether they represent a novel entity or a myxoid variant of angiomatoid fibrous histiocytoma (AFH) remains a matter of debate. We describe the case of a 58-year-old woman with a previous history of breast cancer that developed progressive neurological decline due to a large mass located in the left lateral ventricle of the brain. Histology revealed a mesenchymal tumour with multinodular growth, variable cellularity, prominent myxoid stroma and numerous amianthoid fibres. No evidence of pseudo-capsule or lymphoid cuffing was identified. RNA sequencing disclosed EWSR1–CREB1 gene fusion. Only 20 cases of intracranial mesenchymal tumours harbouring these translocations have been described, mostly in adolescents and young adults and with dural attachment. Occurrence in this age group and with intraventricular location has been even more rarely reported. A better understanding of tumour behaviour is needed to establish treatment guidelines and improve patient outcome.

最近描述了在EWSR1和CREB家族转录因子之间融合的类胶质间充质肿瘤。它们是否代表血管瘤样纤维组织细胞瘤（AFH）的新型实体还是类淀粉样变体，尚有争议。我们描述了一个58岁的女性，该女性先前患有乳腺癌，由于位于大脑左外侧脑室的大量肿块而导致进行性神经功能减退。组织学显示间充质性肿瘤具有多结节性生长，可变的细胞性，突出的粘液样基质和许多类花样纤维。没有发现伪胶囊或淋巴囊套扎的证据。RNA测序揭示了EWSR1-CREB1基因融合。仅描述了20例具有这些易位的颅内间充质肿瘤，多见于青少年和成年人，并伴有硬脑膜附着。在这个年龄段并伴有脑室内定位的病例很少见。需要对肿瘤行为有更好的了解，以建立治疗指南并改善患者预后。