摘要目的:探讨中枢神经系统间叶性软骨肉瘤（mesenchymal chondrosarcoma，MCS）的临床病理学特征。方法:收集福建医科大学附属第一医院2010年9月至2020年9月9例中枢神经系统MCS患者的临床资料、影像学检查、组织病理学及免疫组织化学特征，行荧光原位杂交（FISH）检测NCOA2基因重排情况。结果:9例患者中男性3例，女性6例；年龄1~59岁（中位年龄31岁）。6例位于颅内，3例位于椎管内，大多与硬膜关系密切，术前影像学多诊断为脑膜瘤。显微镜下呈典型的双向分化模式，由未分化间叶性小细胞及分化良好的透明软骨岛2种成分构成。小细胞区表达SOX9（9/9）、CD99（8/9），未见BRG1及INI1缺失；软骨样区表达SOX9（9/9）、S-100蛋白（8/9）。5例检测到NCOA2信号，均呈NCOA2基因分离探针阳性（5/5）。8例随访4~124个月，3例在1年内复发，其中2例死亡。结论:中枢神经系统MCS是一种极罕见的恶性肿瘤，常与硬膜关系密切，术前影像学诊断正确率低，需与中枢神经系统的其他小圆细胞肿瘤或其他类型的软骨肉瘤鉴别，FISH检测查见NCOA2基因断裂可作为较好的指标支持MCS的诊断。

abstractsObjective:To investigate the clinicopathological features of central nervous system (CNS) mesenchymal chondrosarcoma (MCS).Methods:Nine cases of CNS MCS were collected at the First Affiliated Hospital of Fujian Medical University from September 2010 to September 2020. The clinical,imaging,histopathological and immunohistochemical features were reviewed. NCOA2 gene rearrangement was evaluated by fluorescence in situ hybridization (FISH).Results:There were three male and six female patients, with age range of 1 to 59 years (median 31 years). Six cases were intracranial and three cases were intraspinal, and the tumors showed dural attachment. They were often diagnosed as meningioma basing on preoperative imaging. Microscopically, the tumors showed a characteristic biphasic histologic pattern composed of undifferentiated mesenchymal small cells and well-differentiated hyaline cartilage islands. The small cells area were positive for SOX9 (9/9), CD99 (8/9), and without BRG1 and INI1 deletion. The cartilaginous component expressed SOX9 (9/9) and S-100 protein (8/9). NCOA2 gene break apart signal was identified in five cases (5/5). Eight patients were followed up for 4-124 months. Three patients (3/8) had recurrences within one year and two patients died of the tumor.Conclusions:CNS MCS is an extremely rare malignant neoplasm with a propensity to dural involvement. Preoperative imaging has low diagnostic accuracy. CNS MCS should be differentiated from other CNS small round cell tumors and chondrosarcoma. FISH detection of NCOA2 gene rearrangement will assist the diagnosis of MCS.