滑膜肉瘤石蜡包埋组织SYT-SSX融合基因检测的临床病理意义

目的：探讨在石蜡包埋组织中检测SYT－SSX融合基因的可行性及其对滑膜肉瘤的诊断,分型和鉴别诊断的价值。方法：收集滑膜肉瘤标本38例,以恶性周围神经鞘膜瘤,纤维肉瘤,平滑肌肉瘤,尤文肉瘤,血管外皮肉瘤和转移性腺癌作为对照,共40例,均为甲醛固定,石蜡包埋组织,用逆转录－聚合酶链反应（RT－PCR）方法检测SYT－SSX融合基因mRNA表达,以看家基因PBGD作为内对照检测mRNA质量。结果：78例标本中64例（占82．1％）可检出PBGD mRNA表达,38例滑膜肉瘤中33例中可检出SYT－SSX融合基因mRNA表达,对照组无一例检出SYT－SSX基因,去除PBGD及SYT－SSX均阴性病例1例,滑膜肉瘤SYT－SSX融合基因检出率为89．2％（33／37）,33例SYT－SSX阳性滑膜肉中,SYT－SSX1型22例,SYT－SSX2型6例,5例无法区分。融合基因类型与滑膜肉瘤组织学类型有关。10例双相型滑膜肉瘤均为SYT－SSX1型,而18例单相型滑膜肉瘤中SYT－SSX1型12例,SYT－SSX2型6例,二者差异有统计学意义（P＜0．05）,结论：（1）从石蜡包埋组织中检测SYT－SSX融合基因对滑膜肉瘤有较高的敏感性和特异性,可用于滑膜肉瘤的诊断和鉴别诊断;（2）SYT－SSX融合基因类型与滑膜肉瘤组织学类型相关,SYT－SSX2型仅见于单相型。     

滑膜肉瘤的融合基因检测分析

目的：基于存在染色体易位所致特异的SYT－SSX融合基因,证实可在滑膜肉瘤组织石蜡切片上检测出并探讨其在诊断中的价值。方法：采用逆转录－聚合酶链反应,检测并分析20例滑膜肉瘤（组织学亚型15例单相,5例双相）的SYT－SSX转录物,并对照相应病理学所见,结果：所检20例滑膜肉瘤中,有19例（95％）出现特异SYT－SSX逆转录聚酶链反应产物,其中13例具有SYT－SSX2融合基因的肿瘤有10例呈组织学单相分化。结论：SYT－SSX融合基因转录物可在石蜡切片和组织块中获得满意结果。具有较好的灵敏性,是滑膜肉瘤所特有的诊断标志物,它的亚类分型（SYT－SSX1和SYT－SSX2）,可能成为预后推测指征。     

荧光原位杂交在滑膜肉瘤诊断中的应用

滑膜肉瘤是儿童及青少年期常见的软组织肿瘤,约占软组织恶性肿瘤的2％～10％。好发于大关节周围,也可见于其他关节、软组织,还可发生于肺、前列腺、肾等脏器。组织学可分为双相分化型、单相纤维型、单相上皮型、低分化型H0,其中前2种最常见。由于其形态多样,发病部位广泛,免疫组织化学染色又缺乏特异的抗体,有时会造成病理诊断的困难。细胞和分子遗传学研究发现,90％以上的滑膜肉瘤存在特异的t（X;18）（p11．2;q11．2）,导致位于18号染色体SYT基因易位,和位于X染色体上SSX基因产生SYT—SSX融合基因。目前国内检测该融合基因均使用逆转录-聚合酶链反应（RT—PCR）。我们收集儿童滑膜肉瘤4例,探讨运用荧光原位杂交（FISH）法对甲醛固定、石蜡包埋组织检测其融合基因的可行性。     

免疫组织化学染色和SYT-SSX融合基因检测在滑膜肉瘤诊断中的价值

目的评价免疫组织化学染色和SYT-SSX融合基因检测在滑膜肉瘤诊断中的价值与应用范围。方法收集可能为滑膜肉瘤的病例195例,根据临床表现、组织学形态和免疫组织化学染色结果将其分成确诊、高度可疑和可疑滑膜肉瘤,利用逆转录一聚合酶链反应（RT-PCR）技术检测石蜡包埋组织中SYT-SSX融合基因的表达,并比较其与免疫组织化学PV6000二步法染色之间的关系,评价各自的诊断价值。结果确诊、高度可疑和可疑滑膜肉瘤分别为62（31．8％）、49（25．1％）和84例（43．1％）。179例（91．8％）样本能够进行SYT-SSX的RT-PCR检测,其中140例（78．2％）呈阳性。SYT-SSX在确诊、高度可疑和可疑病例中的阳性率分别为94．7％（54／57）、86．0％（37／43）和62．0％（49／79）。上皮膜抗原（EMA）在确诊和高度可疑滑膜肉瘤SYT—SSX阳性病例中的阳性率明显高于其SYT-SSX阴性病例（分别P=0．022,P=0．010）,且EMA与SYT-SSX表达呈正相关（分别rs=0．431,P=0．001．rs=0．463,P=0．002）,而细胞角蛋白、波形蛋白和S-100蛋白在两类病例中的阳性率差异无统计学意义（P〉0．05）;4种指标在可疑滑膜肉瘤SYT-SSX阳性和阴性病例中的表达差异无统计学意义（P〉0．05）。结论利用传统诊断方法可以确诊的滑膜肉瘤不必进行SYT-SSX检测;EMA免疫组织化学染色在高度可疑滑膜肉瘤中的诊断价值与SYT—SSX的RT—PCR检测相近,可以代替后者;但是,融合基因的RT-PCR分析对可疑滑膜肉瘤的确诊具有重要意义。     

SYT在诊断单相纤维型滑膜肉瘤中的价值

目的 探讨SYT在单相纤维型滑膜肉瘤(monophasic fibrous synovial sarcoma,MFSS)的诊断及与其它梭形细胞肿瘤鉴别诊断中的作用.方法 收集MFSS 36例、其它梭形细胞肿瘤32例,其中包括恶性外周神经鞘膜瘤7例、纤维肉瘤6例、平滑肌肉瘤4例、恶性纤维组织细胞瘤7例和孤立性纤维性肿瘤8例,检测sYT蛋白在上述病例中的表达.结果 SYT在MFSS中的阳性表达率为91.67%(33/36),其中15例呈弥漫强阳性表达(>80%的瘤细胞核呈强阳性),12例呈不同程度的阳性表达,50%～80%的瘤细胞核呈强阳性表达.SYT在其他梭形细胞间叶肿瘤中的阳性表达率为59.37%(19/32),其中6例呈弥漫强阳性表达(>80%的瘤细胞核呈强阳性),7例呈不同程度的阳性表达,50%～80%的瘤细胞核呈强阳性.结论 SYT蛋白在MFSS和其他梭形细胞肿瘤中均有较强的阳性表达,提示SYT抗体在MFSS与其他梭形细胞肿瘤的鉴别诊断中作用有限.     

34例滑膜肉瘤分子遗传学改变的诊断学意义

目的 探讨石蜡包埋滑膜肉瘤组织中t(x；18)(p11．2；q11．2)染色体易位融合基因SYT-SSX mRNA表达的诊断学意义和应用价值。方法 收集滑膜肉瘤标本34例，以14例梭形细胞肉瘤和小圆细胞肉瘤做对照(包括2例纤维肉瘤、2例平滑肌肉瘤、1例恶性神经鞘膜瘤、4例Ewing肉瘤、2例腺泡型横纹肌肉瘤、2例恶性黑色素瘤、1例血管外皮瘤)。在进行免疫组织化学指标检测的基础上，用一步法逆转录-聚合酶链反应(RT-PCR)技术检测34例石蜡包埋滑膜肉瘤组织中SYT-SSX的表达。结果 34例滑膜肉瘤中30例获得有效RNA，28例(93．3％)检出SYT-SSX融合基因表达。其中14例表达SYT-SSXl型者中10例为双相型，9例表达SYT-SSX2型者中5例为单相分化型，5例SYT-SSXl／2均未检出。对照组均未检出SYT-SSX基因的表达。结论 SYT-SSX融合基因表达可作为诊断滑膜肉瘤新的分子诊断指标。一步法RT-PCR是一种理想而可行的用于石蜡包埋滑膜肉瘤组织SYT-SSX融合基因检测的分子诊断技术。     

胃原发微小滑膜肉瘤1例

滑膜肉瘤是一种起源未定的具有间质和上皮双相分化的软组织肉瘤类型,好发于年轻人四肢大关节附近的深部软组织。原发于消化管道的滑膜肉瘤极为罕见,本文报道1例发生于35岁女性胃体的原发滑膜肉瘤,镜下表现为单相梭形细胞亚型,SYT断裂探针检测结果阳性。胃原发滑膜肉瘤罕见,易误诊为胃肠道间质瘤,认识其存在并熟悉相关组织形态学、免疫...     

原发性肾脏滑膜肉瘤临床病理及分子遗传学分析

目的探讨原发性肾脏滑膜肉瘤的临床病理特征、诊断及鉴别诊断。方法对1例罕见的原发性肾脏滑膜肉瘤进行光镜观察和免疫组化染色,并用RT-PCR方法在石蜡包埋组织中检测SYT-SSX融合mRNA表达,结合文献分析讨论。结果肿瘤由核分裂活跃的单形的梭形细胞组成,呈交织的束状或实性排列,部分区域呈血管外皮瘤样图像,未见上皮分化成分;囊性区囊内衬核分裂不活跃的多边形的鞋钉样上皮。免疫表型瘤细胞vimentin、CD99、bcl-2、S-100均阳性,Ki-67强阳性;CK(AE1/AE3)、EMA、SMA、CD117、CD34、p53、ER、PR均阴性。RT-PCR方法检测到肿瘤组织中有SYT-SSXmRNA表达,对照组SYT-SSX无表达。患者术后5月内死亡。结论原发性肾脏滑膜肉瘤罕见,需要与肾脏其他一些梭形细胞肿瘤相鉴别,分子遗传学检测SYT-SSX融合mRNA有助于其诊断和鉴别诊断。     

恶性小圆细胞肿瘤免疫组织化学及病理组织学分析

本文分析57例恶性小凶细胞肿瘤(MSRCT)免疫组化表型及病理形态。结果表明:兔抗鸡结蛋白及(或)兔抗人肌红蛋白可作为横纹肌肉瘤的标志;神经母细胞瘤、嗅神经母细胞瘤及原始外周神经外胚层瘤的免疫组化特征为NSE阳性,而Vim阴性;抗NSE抗血清特异性差,其他MSRCT亦可与之反应。尤文肉瘤Vim阳性,有些病例NSE阳性。未分化滑膜肉瘤Vim阳性;部分病例Ker及(或)EMA阳性,可有假阴性。LCA是恶性淋巴瘤特异性标记。α_1-ACT对MSRCT鉴别诊断无价值。     

荧光原位杂交检测石蜡包埋滑膜肉瘤组织中染色体易位的临床病理学意义

目的探讨荧光原位杂交（FISH）方法在石蜡包埋滑膜肉瘤组织中检测染色体易位的可行性及其在临床病理学中的应用价值。方法收集42例滑膜肉瘤,采用LSI SYT（18q11．2）双色分离型探针在石蜡切片上与瘤细胞进行杂交,所有病例同时行逆转录-聚合酶链反应（RT-PCR）检测SYT—SSX融合基因及其亚型,另以9例其他类型的软组织肿瘤作为阴性对照。结果FISH显示,42例中37例（88．1％）于胞核内可见清晰的荧光信号,其中33例（78．5％）显示SYT基因易位。RT—PCR法的检出率为83．8％（35／42）,两者的联合检出率为92．9％（39／42）。FISH和RT-PCR的检测结果密切相关。结论FISH可应用于石蜡包埋的存档组织,FISH较RT-PCR方法操作更为简便省时,敏感性和特异性均较高。由于FISH的实验成本可以有效控制,又节省劳动力成本,因而可以在软组织肿瘤的临床病理诊断和研究工作中应用。     

Immunostaining for SYT protein discriminates synovial sarcoma from other soft tissue tumors: analysis of 146 cases.

Synovial sarcoma in its classic biphasic form can be distinguished readily from other soft tissue lesions; however, monophasic and poorly differentiated forms are diagnostically more problematic. For this reason, we assessed the efficacy of immunostaining for SYT and SSX1 proteins, the gene products resulting from unique synovial sarcoma translocation, to distinguish synovial sarcoma from other soft tissue lesions. A total number of 146 cases were analyzed, including 47 synovial sarcoma cases (all of which were verified by FISH to have t(X; 18) translocation and SYT-SSX fusion gene) and 99 soft tissue tumors of various types. A polyclonal IgG antibody against SYT was used to stain formalin-fixed paraffin embedded tissues. Forty-one out of 47 (87%) synovial sarcoma displayed strong positive nuclear staining (ranging from 80 to 90% of the tumor cells) for SYT antibody. Nineteen of 99 (19%) non-synovial sarcoma cases showed variable nuclear and cytoplasmic staining with SYT, which ranged from 20 to 60% of tumor nuclei, and included malignant peripheral nerve sheath tumor (5/25), solitary fibrous tumor (2/14), Ewing sarcoma (2/6), low grade fibromyxoid tumor (2/4), extraskeletal mesenchymal chondrosarcoma (2/6), gastrointestinal tumor (4/17), epithelioid sarcoma (2/2). The remaining non-synovial sarcomas were negative. This is the first study demonstrating SYT protein expression in tissue sections of synovial sarcoma. This method could provide an easy, rapid and widely applicable means of assisting in the diagnosis of synovial sarcoma, particularly when material and/or resources are unavailable for PCR or FISH-based testing. However, as variable weak staining for SYT may be encountered in a small percentage of non-synovial sarcoma sarcomas, a positive interpretation should be made only when the staining is strong, nuclear and present in the majority of cells.     

滑膜肉瘤t(X;18)易位断裂点基因组DNA序列特征分析

目的 分析滑膜肉瘤t(X;18)染色体易位断裂点基因组DNA序列特征,探讨其与滑膜肉瘤t(X;18)染色体易位发生的关系。方法 采用长距离聚合酶链反应（PCR）及DNA测序技术,对2例滑膜肉瘤新鲜标本t(X;18)染色体易位断裂点基因组DNA序列进行了扩增及序列分析。结果 2例滑膜肉瘤标本均存在t(X;18)染色体易位,分别导致SYT-SSX1和SYT-SSX2融合基因形成,DNA序列分析显示,SYT基因第10内含子分别与SSX1和SSX2基因的第4内含子发生融合。在3种基因的断裂点附近均存在与共有易位素（translin)识别序列高度同源的序列,还发现3种基因的断裂点靠近,甚至位于呈回文结构的寡核革酸序列中,SSX1和SSX2基因第4内含子断裂点位于Alu重复序列附近,而SYT基因第10内含子断裂点上游和下游各500碱基内均未发现Alu或其他重复序列。在SYT两断裂点之间的DNA序列中存在一处拓扑异构酶Ⅱ的识别序列,但与两断裂点距离较远。结论 滑膜肉瘤染色体易位所涉及的3种基因的基因组断裂点区域存在特征性的序列,可能与滑膜肉瘤染色体易位的发生有关。     

Clinical importance of genomic imbalances in synovial sarcoma evaluated by comparative genomic hybridization

The t(X;18)(p11.2;q11.2) (SYT/SSX1 or SSX2) is represented in more than 95% of synovial sarcoma. Even if recent data has implicated that the type of fusion gene (SYT/SSX1 or SYT/SSX2) can be of prognostic importance, the cellular and molecular mechanisms underlying the clinical behavior of synovial sarcoma are still poorly understood. To approach this issue, we investigated whether secondary genetic aberrations may influence the clinical outcome of synovial sarcoma. Clinical outcome with reference to comparative genomic hybridization (CGH) findings (losses or gains of genetic material) were analyzed for a uniquely large modern material of 69 synovial sarcomas. Thirty-five of 69 specimens showed DNA sequence copy number changes. The frequency of aberrations/tumor were higher (mean 4.7) for monophasic tumors than for biphasic tumors (mean 2.1). Gains of the whole or parts, including the long arm, of chromosome 8 were significantly overrepresented in large tumors (> 5 cm), suggesting that tumors with this genetic abnormality have an increased growth rate. No difference regarding metastasis-free or overall survival was seen between patients with or without tumors containing secondary copy number changes. No specific copy number change was linked to a significantly improved or impaired metastasis-free survival.     

A novel case of synovial sarcoma of the kidney: impact of SS18/SSX analysis of renal hemangiopericytoma-like tumors.

We report a new case of synovial sarcoma of the kidney. The patient underwent nephrectomy because of a large tumor in the right kidney. The histologic diagnosis was hemangiopericytoma. Less than 1 year after primary surgery the patient was reoperated due to massive local recurrence. Histology now revealed a poorly differentiated tumor tissue with hemangiopericytoma-like features. Immunostainings showed immunoreactivity to cytokeratin, epithelial membrane antigen, and vimentin. The tumor was negative to CD34 and factor VIII. The tumor cell proliferation, assessed by Ki-67, was high. RT-PCR analysis and sequence analysis demonstrated the presence of SS18/SSX2 fusion gene. Review of the histologic specimens from the original tumors confirmed hemangiopericytoma-like morphology. The new diagnosis was poorly differentiated synovial sarcoma. At the time of reoperation, lung metastases were detected radiologically, reflecting a very aggressive phenotype. To our knowledge, this is the third case of poorly differentiated synovial sarcoma of the kidney. Common for all these three cases is the hemangiopericytoma-like histology and a very aggressive clinical behavior. These circumstances accentuate the impact of SS18/SSX analysis in diagnosis of renal hemangiopericytoma-like tumors.     

Synovial sarcoma (SS): new perspectives supported by modern technology

Based upon the experience of 256 cases of synovial sarcoma (SS), the present review analyzes structural, biological and molecular pathology of this poorly known sarcoma. The histology displays a multiphenotype with two major components: biphasic and monophasic SS. In addition, a number of variants have been described: undifferentiated Ewing's like, myoxid and predominantly epithelial (monophasic epithelial sarcoma). Microcalcifications and squamous metaplasia are often seen in the tumor. Immunohistochemistry with EMA and cytokeratin in the epithelial or epithelioid component is diagnostic for SS together with vimentin positivity in the spindle cells. Several other epitopes are also expressed (CD99, CD56, C-MET, HGF/SF, CD44). The ultrastructure confirms the variegated pattern of the neoplasm demonstrating the epithelial component and the epithelioid or spindle cell type closely associated with each other. Transition of epithelial cells to epithelioid and spindle-like mesenchymal component is seen. Nude-mice xenografts and cell lines after in vitro culture confirm heterogeneity of this sarcoma. Molecular histology of the SS has provided high utility not only for their differential diagnosis due to a specific chromosomal translocation: t(X;18)(p11.2;q11.2) but also after cloning these breakpoints resulting in the fusion of two genes: SYT at 18q11 and SSX at Xp11. Further observations have lead to distinguish the existence of two related genes: SSX1 and SSX2, that provide a highly specific and sensitive diagnostic marker for SS. Moreover, clinical correlations have demonstrated that SYT-SSX1 leads to a poor clinical outcome while the fusion SYT-SSX2 provides survival advantages to the patients.