荧光原位杂交技术检测滑膜肉瘤SS18基因易位的诊断价值

Diagnostic Value of Dual-color Break-apart In Situ Hybridization for Detection of SS18 Rearrangement in Synovial Sarcoma

【目的】探讨荧光原位杂交(FISH)技术检测石蜡包埋滑膜肉瘤组织中染色体易位的病理学辅助诊断意义。【方法】收集168例肿瘤标本,其中75例确诊滑膜肉瘤、33例疑似滑膜肉瘤,采用LSI SS18(18ql1.2)双色断裂分离探针检测SS18基因易位状况;60例非滑膜肉瘤作为阴性对照,制定SS18基因易位阳性的判断阈值。【结果】165例肿瘤标本成功进行FISH检测,其中129例(78.2%)SS18基因二体性,36例(21.8%)SS18基因多拷贝数。根据建立的SS18基因易位阳性的判断阈值,确诊滑膜肉瘤的病例中85.1%(63/74)可检测到SS18基因易位,余11例结合形态学及免疫组化结果仍诊断为SS;疑似滑膜肉瘤的病例中71.1%(22/31)可检测到阳性结果,余9例最终诊断为其他肿瘤。【结论】FISH法检测SS18基因易位是滑膜肉瘤诊断的有效辅助手段,滑膜肉瘤的最终诊断及鉴别诊断需结合形态学、免疫组化及分子生物学检测的综合分析。

【Objective】 To assess the value of molecular genetics detection of SS18 rearrangement for the diagnosis of synovial sarcoma（SS）.【Methods】 Interphase FISH with a LSI SS18（18ql1.2） dual color,break apart probe was utilized in 168 soft tissue tumor specimens including 75 SS in the primary diagnosis,33 potential SS and 60 non-SS.【Results】 FISH was available in 165 specimens involved diploid of SS18 gene in 129 cases and multiple copies in 36 ones.According to the cutoff value based on non-SS,85.1%（63/74） of SS in the primary diagnosis and 71.0%（22/31） of potential SS were considered to be positive for SS18 gene rearrangement.Combined with morphological feature and immunohistochemical results,eleven cases in SS and nine cases in potential SS,negative for SS18 rearrangement,were finally diagnosed with SS and other groups of tumor,respectively.【Conclusions】 The break-apart interphase FISH test is a powerful aid for diagnosing synovial sarcoma,but results must be intrpreted in the light of morphological features and immunohistochemical data.