Tvrdík Daniel, Povýsil Ctibor, Svatosová Jana, Dundr Pavel
Institute of Pathology, General Faculty Hospital, Studnickova 2, Prague 2, 128 00, Czech Republic.
Med Sci Monit. 2005 Mar;11(3):MT1-7.
Synovial sarcomas comprise up to 10 percent of malignant soft tissue tumors, and most are characterized by the chromosomal translocation t(X;18) (pl 1.2;q11.2), which results in the expression of SYT-SSX fusion transcripts. These tumors include two major histological subtypes, biphasic and monophasic. Diagnosing biphasic synovial sarcomas does not usually pose a problem, whereas the monophasic spindle-cell form can be difficult to distinguish from other spindle-cell neoplasms using histological and immunohistochemical profiles only.
MATERIAL/METHODS: We investigated the presence of SYT-SSX1/2 chimeric RNA in tumors from 7 patients. We applied amplification of the specific fusion transcripts by reverse transcriptase-polymerase chain reaction (RT-PCR) in fresh, frozen tumors. We also developed a method useful for RT-PCR SYT-SSX fusion transcript detection in formalin-fixed, paraffin-embedded tissue.
We found that both histological subtypes of synovial sarcoma were SYT-SSX positive. Moreover, we observed a correlation between histological subtype and type of SYT-SSX fusion transcript. Biphasic synovial sarcoma expressed the SYT-SSX1 fusion transcript, whereas the monophasic subtype expressed the SYT-SSX2 fusion transcript.
The detection of SYT-SSX1/2 fusion transcripts by RT-PCR is a valuable diagnostic marker of synovial sarcoma which can be used for the reclassification of cases whose diagnosis is difficult by routine methods.
滑膜肉瘤占恶性软组织肿瘤的比例高达10%，大多数滑膜肉瘤的特征是染色体易位t(X;18)(p11.2;q11.2)，这导致SYT-SSX融合转录本的表达。这些肿瘤包括两种主要的组织学亚型，双相型和单相型。诊断双相型滑膜肉瘤通常不成问题，而单相型梭形细胞型仅通过组织学和免疫组织化学特征可能难以与其他梭形细胞肿瘤区分开来。
材料/方法：我们研究了7例患者肿瘤中SYT-SSX1/2嵌合RNA的存在情况。我们应用逆转录聚合酶链反应（RT-PCR）在新鲜冷冻肿瘤中扩增特异性融合转录本。我们还开发了一种用于在福尔马林固定、石蜡包埋组织中检测RT-PCR SYT-SSX融合转录本的方法。
我们发现滑膜肉瘤的两种组织学亚型均为SYT-SSX阳性。此外，我们观察到组织学亚型与SYT-SSX融合转录本类型之间存在相关性。双相型滑膜肉瘤表达SYT-SSX1融合转录本，而单相型亚型表达SYT-SSX2融合转录本。
通过RT-PCR检测SYT-SSX1/2融合转录本是滑膜肉瘤的一种有价值的诊断标志物，可用于对常规方法诊断困难的病例进行重新分类。
