Objective: To investigate histopathological characteristics, and differential diagnoses of childhood synovial sarcoma. Methods: HE staining, immunohistochemical staining and fusion gene detection by FISH were performed in 12 cases of synovial sarcoma in childhood at Beijing Children's Hospital from 2016 to 2018. Results: There were 6 cases of biphasic type, 1 case of monophasic epithelial type, 3 cases of monophasic spindle cell type and 2 cases of poorly differentiated synovial sarcomas. EMA, CKpan, bcl-2, CD99, TLE1 and CD34 immunostain positivities were observed in 10/12, 9/12, 12/12, 10/12, 10/12 and 0/12 cases respectively. Unique INI1 immunohistochemical staining was observed in 9/12 cases. SS18-SSX gene fusion was detected in 8 of 11 cases by FISH. Conclusions: Synovial sarcoma is rare in children. Histological morphology combined with immunohistochemistry and FISH SS18-SSX fusion gene detection are important for the diagnosis and differential diagnosis of synovial sarcoma in children.
目的： 探讨儿童滑膜肉瘤的临床病理学特点及鉴别诊断。 方法： 收集2016至2018年北京市儿童医院诊断的12例儿童滑膜肉瘤，病变组织行HE染色、免疫组织化学标记和荧光原位杂交检测，观察其组织学形态、分子表达及遗传学情况。 结果： 双相型6例，单向上皮型1例，梭形细胞型3例，分化差型2例。上皮细胞膜抗原、广谱细胞角蛋白、bcl-2、CD99、TLE1阳性比例分别为10/12、9/12、12/12、10/12和10/12，CD34均为阴性，INI1表达呈特殊模式者占9/12。11例经FISH检测，SS18-SSX融合基因阳性比例为8/11。 结论： 滑膜肉瘤是儿童少见的具有双向分化特征的恶性软组织肿瘤，明确诊断需结合组织形态、免疫组织化学染色及分子病理特点综合考虑。.
Keywords: Immunohistochemistry; Pathology, molecular; Sarcoma, synovial.