Objective: To investigate the clinicopathological and molecular genetic characteristics of intracranial mesenchymal tumors with FET::CREB fusion transcript. Methods: The clinical and imaging data of 6 cases of intracranial mesenchymal tumors with FET::CREB fusion from December 2018 to December 2023 were collected at the First Affiliated Hospital of Zhengzhou University. Their histological features, immunophenotype and molecular characteristics were analyzed. Results: Among the 6 patients, 4 were males and 2 were females, and the median age was 20 years. The clinical symptoms were increased intracranial pressure in 5 cases and epilepsy in 1 case. The lesion sites were cerebellum (2 cases), frontal lobe (2 cases), parietal lobe (1 case), and cranioorbital communication (1 case). The radiological features mainly showed solid or cystic components, with obvious annular enhancement on MRI. The histopathological features showed a wide spectrum of morphology, clear boundaries and fibrous pseudocapsule. The tumor cells were arranged in a lamellar or nodular pattern, and some in cord or loose network. The tumor cells were spindle, oval, epithelioid or stellate. The stroma was collagenous or mucin-rich, and accompanied by abundant lymphocytes and plasma cells infiltration. By immunohistochemical staining, desmin, CD99 and EMA were expressed in 6 cases, CD68 in 1 case, MUC4 in 1 case, synaptophysin in 2 cases, and ALK in 1 case. The Ki-67 proliferation index was between 1%-15%. Molecular analysis showed EWSR1::ATF1 fusion in 3 cases, EWSR1::CREB1 fusion in 2 cases, and EWSR1::CREM fusion in 1 case. Conclusions: Intracranial mesenchymal tumors with FET::CREB fusion are relatively rare and typically occur in children and younger adults. These tumors have a broad morphological spectrum and often express desmin, CD99 and EMA. The molecular characteristics are the gene fusions of FET family (mainly EWSR1, FUS) with CREB family transcription factors (ATF1, CREB1 or CREM). It is necessary to distinguish these tumors from meningiomas and solitary fibrous tumors, and the combination of immunohistochemical staining and molecular genetic testing can effectively help identify these tumors.
目的： 探讨颅内间叶源性肿瘤伴FET：：CREB融合阳性型的临床病理学特征及分子遗传学特征。 方法： 收集郑州大学第一附属医院2018年12月至2023年12月确诊的6例颅内间叶源性肿瘤伴FET：：CREB融合阳性型的临床及影像学资料，分析其组织学、免疫表型及分子遗传学特征。 结果： 6例患者中男性4例，女性2例，年龄11~49岁，中位年龄20岁。5例是以颅内压增高症状入院，1例是以癫痫症状入院。病变部位为小脑2例，额叶2例，顶叶1例，颅眶沟通1例，其中2例患者有既往脑部手术病史。影像学特征：磁共振成像主要为实性或囊实性占位性病变，增强可见明显强化或环状强化。病理学特征：肿瘤组织形态学谱系较广，镜下一般边界清楚，可有纤维性假包膜。肿瘤细胞排列成实性片状或结节状，部分病例可见条索状或疏松网状排列；肿瘤细胞呈梭形、卵圆形、上皮样、横纹肌样或星芒状，间质可伴多少不等的胶原化纤维及黏液变，并伴有丰富的淋巴细胞、浆细胞浸润。免疫组织化学染色6例均表达结蛋白、CD99及上皮细胞膜抗原（EMA），1例表达CD68，1例表达MUC4，2例表达突触素，1例表达间变性淋巴瘤激酶，Ki-67阳性指数1%~15%。分子检测结果3例为EWSR1：：ATF1融合，2例为EWSR1：：CREB1融合，1例为EWSR1：：CREM融合。 结论： 颅内间叶源性肿瘤伴FET：：CREB融合阳性型偏好发生于儿童及较年轻的成人，较为少见，形态学谱系较广泛，免疫组织化学常表达结蛋白、CD99及EMA，分子特征是FET家族（主要为EWSR1、FUS）与CREB家族转录因子（ATF1、CREB1或CREM）融合。需鉴别脑膜瘤、孤立性纤维性肿瘤等，免疫组织化学及分子的联合运用能有效帮助鉴别这类肿瘤。.