Objective: To investigate the morphologic, immunohistochemical, genetic, clinical features and prognosis of Ewing-like BCOR-CCNB3 gene fusion undifferentiated sarcoma (BCOR-CCNB3 fusion sarcoma). Method: Seventeen Ewing-like sarcoma cases were screened for CCNB3 expression and BCOR-CCNB3 fusion transcripts by immunohistochemistry and RT-PCR among 260 cases of Ewing-like sarcomas collected during Jan, 2006 to Dec, 2015. Three cases of BCOR-CCNB3 fusion sarcoma were found among 17 atypical Ewing sarcomas, and follow-up were conducted. Results: The harboring of BCOR-CCNB3 fusion transcript was confirmed by RT-PCR and directly sequencing results. The three patients aged between 8 and 11 years old. Two of them were male and the other one was female. One patient achieved a complete response after chemotherapy, the other two died without chemotherapy after surgical excision in 12 months. Tumor cells in all 3 cases showed diffuse nuclear CCNB3, TLE1 and cyclin D1 positivity, while CCNB3 (0/12), TLE1 (1/12) and cyclin D1 (4/12) positivity was infrequent in the 12 cases of classical Ewing's sarcoma. The oval or plump spindle tumor cells with fine chromatin arranged in solid pattern, the nucleoli was inconspicuous. The delicate capillary networks were obvious in the tumor. Conclusion: With a detailed description of the histological spectrum, immunohistochemical features and clinical characteristic of BCOR-CCNB3 sarcoma, justify distinction from Ewing sarcoma could be possible.
目的： 探讨具有BCOR-CCNB3融合基因的尤文样未分化肉瘤(BCOR-CCNB3肉瘤)的临床病理特征、免疫表型、鉴别诊断及预后。 方法： 收集2006年1月至2015年12月病理诊断为Ewing/PNET肉瘤或尤文样肉瘤260例，其中17例尤文样肉瘤采用CCNB3免疫组织化学、逆转录聚合酶链反应(RT-PCR)检测BCOR-CCNB3融合基因，3例为BCOR-CCNB3肉瘤，另选取12例尤文肉瘤作为对照，进行随访并复习相关文献。 结果： RT-PCR及测序结果显示3例均携带BCOR-CCNB3融合基因。3例BCOR-CCNB3肉瘤中，女性1例，男性2例；患者年龄8～11岁。随访时间12～56个月，2例1年内死亡，1例复发。BCOR-CCNB3肉瘤肿瘤细胞圆形、短梭形，呈实性片状排列，染色质细，核仁不明显；有纤细的毛细血管结构分隔肿瘤细胞，与肾脏透明细胞肉瘤形态相近。CCNB3、TLE1、cyclin D1均呈弥漫的细胞核阳性(3/3)。在12例尤文肉瘤中，CCNB3均为阴性(0/12)，1例(1/12)TLE1弱阳性，4例(4/12)cyclin D1阳性。 结论： BCOR-CCNB3肉瘤具有独特的形态、免疫表型和临床特点，是一种独立的肿瘤类型，需要与Ewing/PNET肉瘤进行鉴别诊断，CCNB3阳性是该类型肿瘤较为特异的标志，TLE1和cyclin D1阳性也提示该肿瘤的可能，确诊需要检测BCOR-CCNB3融合基因。.
Keywords: Gene fusion; Immunohistochemistry; Reverse transcriptase polymerase chain reaction; Sarcoma.