儿童滑膜肉瘤临床病理分析

Clinicopathological study of synovial sarcoma in children

目的探讨儿童滑膜肉瘤的临床病理特点和鉴别诊断。方法回顾性分析26例儿童滑膜肉瘤患者的临床资料,统计分析其临床特点、病理学、免疫组织化学及分子遗传学特征。结果 26例儿童滑膜肉瘤,男15例,女11例,男女之比为1.36∶1,年龄4~15岁,平均(12.8±0.3)岁;发生部位:上肢5例,下肢19例,腹壁2例,其中3例出现肺转移;组织学表现:单相纤维型滑膜肉瘤,肿瘤细胞呈梭形,排列成束状,形成大小不等的旋涡状,部分呈弧形,相互交叉,间质可见较多分枝状、裂隙状壁薄血管。双相型滑膜肉瘤,肿瘤组织由梭形细胞及上皮样细胞组成,梭形细胞区及上皮样细胞区相互移行。梭形细胞区结构同单项纤维型SS相似,上皮样细胞区可形成腺样结构,部分可见乳头状结构;低分化型滑膜肉瘤均为小细胞型,肿瘤细胞较小,圆形或多边形,类似外周原始神经外胚层瘤的肿瘤细胞,肿瘤细胞呈小巢状或弥漫片状分布。所有病例均表达波形蛋白、TLE1、上皮角蛋白和(或)上皮膜抗原,均检测到SS18-SSX融合基因。结论儿童滑膜肉瘤组织形态及免疫表型变化多样,几乎可发生在任何部位,导致其与形态学类似的几种软组织肿瘤进行鉴别诊断相对困难,相对特异的TLE1具有较好的鉴别诊断作用,金标准SS18-SSX基因检测可明确诊断,对其分子机制的进一步研究和新一代靶向药物的开发,能显著改善患者的生存质量和预后。

Objective To investigate clinical and pathological characteristics and differential diagnosis of synovial sar- coma（SS） in children. Methods Clinical, pathological, immunohistochemical and molecular genetic characteristics of twenty- six of SS in children were retrospectively analyzed. Results Among of 26 children of SS, 15 cases were male and 11 cases were female（ male ： female means 1.36 ： 1 ） ,which was age ofg to 15 ,the average age was 12.8 ±0.3. Five occured in upper extremity ,19 in lower extremity ,2 in abdominal wall and lung metastasis appeared in 3 children. Histology and morphology of monophasic SS demonstrated spindle tumor cells with arrangement of faciculation, various whirlpool and small portion of curve, and many cladodromous, slit-shaped thin-wall vessels in stroma. In biphasic SS, tumor tissue were composed of spindle and epi- thelial-like cell, and transition between two zones, the structure of spindle cell was similar with the monophasic SS, and the glandular structure was composed of epithelial-like cells, corpora mammillaria appeared in epithelial-like zone. Low differentia- tion SS showed small cells, which was round or polygonal similar with cells forming small nest and diffused shape in primitive neuroectodermal tumor. All cases of SS expressed vimentin, TLE1, cytokeratin and （ or ） epithe（ial membranee antigen, and SS18-SSX fusion gene was detected. Conclusion Histological morphology and immunohistochemical phenotype varies in SS of children,which resulted in difficult differential diagnosis with some soft connective tissue tumor. Relatively specific TLE1 makes a role in differential diagnosis. Gene detection of SS18-SSX can make a final diagnosis and further study in molecular mechanism of SS18-SSX and development of next generation targeted drugs can make marked survival quality and prognosis.