Astrocytoma with high-grade features and MYBL1-MMP16 fusion

Gliomas represent the most common primary intraparenchymal brain tumors in adult and pediatric patients. Neuropathological work-up of these gliomas typically entails the determination of isocitrate dehydrogenase (IDH) mutational status, presence or absence of 1p/19q co-deletion, and O6 methylguanine-DNA methyl-transferase (MGMT) promoter methylation status. We present here an unusual case of a posterior fossa tumor in a 51-year-old female, which was initially diagnosed as astrocytoma with some high-grade features that recurred, displaying even more aggressive features such as infiltration and increased proliferative activity. Both the initially resected and recurrent tumor revealed MYBL1-MMP16 fusion, which is much more commonly found in pediatric low-grade gliomas and, to our knowledge has not been described in the context of an adult glioma. The significance of MYBL1-MMP16 fusion in adult gliomas in relation to survival and likelihood of recurrence is, therefore, unknown and requires more extensive research.

胶质瘤是成人和儿童患者中最常见的原发性脑实质内肿瘤。对这些胶质瘤进行神经病理学检查通常需要确定异柠檬酸脱氢酶（IDH）突变状态、1p/19q是否共缺失以及O6 -甲基鸟嘌呤 - DNA甲基转移酶（MGMT）启动子甲基化状态。 我们在此介绍一例51岁女性后颅窝肿瘤的罕见病例，该肿瘤最初被诊断为具有一些高级别特征的星形细胞瘤，且复发后表现出更具侵袭性的特征，如浸润和增殖活性增加。最初切除的肿瘤和复发的肿瘤均显示出MYBL1 - MMP16融合，这种融合在儿童低级别胶质瘤中更为常见，据我们所知，在成人胶质瘤中尚未有相关描述。 因此，MYBL1 - MMP16融合在成人胶质瘤中与生存和复发可能性的相关性尚不明确，需要更广泛的研究。