Department of Pathology and Laboratory Medicine, Temple University Hospital, Philadelphia, PA 19140, USA.
Department of Biomedical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA 19131, USA.
Int J Mol Sci. 2023 Aug 15;24(16):12814. doi: 10.3390/ijms241612814.
Oncogenic Yes-associated protein (YAP) 1 fusions have been recently identified in several cases of meningioma mostly involving pediatric patients. The meningiomas harboring YAP1-MAML2, which is the most frequent fusion subtype, exhibit activated YAP1 signaling and share similarities with (neurofibromatosis type 2 gene) mutant meningiomas. We reported a rare case of atypical intraparenchymal meningioma with YAP1-MAML2 fusion in a 20-year-old male. The patient presented with an episode of seizure without a medical history. MRI revealed a lesion in the right temporal lobe without extra-axial involvement. The radiological and morphological findings, however, were indistinctive from other intracranial diseases, e.g., vascular malformation and glioma. Immunohistochemical results confirmed the presence of abundant meningothelial cells in the tumor and indicated brain invasion, supporting the diagnosis of atypical intraparenchymal meningioma. Targeted RNA fusion analysis further identified a YAP1-MAML2 rearrangement in the tumor. Non-dural-based intraparenchymal meningiomas are uncommon, and the careful selection of specific tumor markers is crucial for an accurate diagnosis. Additionally, the detection of the fusion gene provides valuable insights into the oncogenic mechanism of meningioma.
致癌性 Yes 相关蛋白 (YAP) 1 融合已在几种脑膜瘤中被发现，主要涉及儿科患者。脑膜瘤中存在 YAP1-MAML2 融合，这是最常见的融合亚型，表现出激活的 YAP1 信号，与 （神经纤维瘤病 2 基因）突变型脑膜瘤具有相似性。我们报道了一例罕见的伴有 YAP1-MAML2 融合的非典型脑实质内脑膜瘤病例，患者为 20 岁男性。患者表现为癫痫发作，无既往病史。MRI 显示右侧颞叶有病变，无外轴累及。然而，影像学和形态学表现与其他颅内疾病（如血管畸形和胶质瘤）无明显区别。免疫组织化学结果证实肿瘤中有丰富的脑膜细胞存在，提示有脑侵犯，支持非典型脑实质内脑膜瘤的诊断。靶向 RNA 融合分析进一步鉴定出肿瘤中存在 YAP1-MAML2 重排。非脑膜基脑实质内脑膜瘤并不常见，仔细选择特定的肿瘤标志物对于准确诊断至关重要。此外，融合基因的检测为脑膜瘤的致癌机制提供了有价值的见解。
