Clinical Pathological Analysis of Synovial Sarcoma

246 Chinese Journal of Clinical Oncology Aug. 2007, Vol.4, No.4 P 246~249 Ling Yang et al.[SpringerLink] DO 1.1007511805.007-0246-.Clinical Pathological Analysis of Synovial SarcomaLing YangOBJECTIVE To investigate the cinical diagnosis and diferential diagno-Bogen Songsis of synovial sarcoma (SS).zhongjie LinMETHODS A total of 41 paraffin-embedded synovial sarcoma samplesWeiming Zhangwere examined by H&E staining, immunohistochemistry staining and the re-verse transcriptase polymerase chain reaction (RT-PCR), in order to provideQinhe Fana scientfic bases for diagnosis and dfferential diagnosis.RESULTS Twelve cases were a biphasic type, 22 cases were a mono-phasic fibrous type, and 7 cases were a pooly dfferentiated type. Thity-sixcases were both CK (and/or EMA) and Vim positive. Five cases were onlyPathology Department of Medical Collge,Vim positive. A SYT-SSX fusion gene was detected in 18 cases by RT.PCR.Tongji University, Shanghai 200092, China.CONCLUSION By observation of the histomorphology, immunohisto-chemistry markers and detection of a SYT-SSX fusion gene, we can make aclinical pathological diagnosis of synovial sarcoma.KEYWORDS: synovial sarcoma, clinical pathology, diag.Corespondence to: Ling Yangnosls.E-mail: doctoryangling@yahoo com.cnINTRODUCTIONSynovial sarcoma is a type of malignant soft tissue tumor, theorigin of which is still unknown. It accounts for 5%~10% of sar-comas[1. Based on biphasic differentiation and clinical findings, itcan be diagnosed clinically. But some cases occur in old patientsand in unusual parts of the body, for example: larynx and throat,lung, kidney, skull base, pleura, major pectoral muscle and heartetc. Diagnosis is dificult in some without an obvious biphasic dif-ferentiation. In order to provide a diagnostic bases for clinical anddifferential diagnosis, we have conducted the study of sS at threelevels: histomorphology, immunohistochemistry and molecularbiology.MATERIALS AND METHODSClinical samplesA total of 41 synovial sarcoma samples were collected from1994~2003 in the JiangSu People's Hospital. All samples werefixed by 10% formalin, and parafin embedded. Following routineH&E staining, all slides were observed microscopically.ImmunohistochemistrySlides were stained by SP methods. The following mouse mono-clonal antibodies(cens were used: CK,Received March 20, 2007; accepted July 10,EMA, Vim, SM中国煤化工A. Products of the2007.DAKO Co. wereY片CNMH G MaixinCo.CJCO ht/:w/w.jc.cn. E-mail:cocr@eyou.comTelFax:86-22- 2352 2919Chinese Journal of Clinical Oncology Aug. 2007,Vol. 4, No.4 P 246~249 Ling Yang et al.247Assessment of positive expression Was conductedwith pain and limitation of joint motion.by considering the strength of positive staining andnumber of positive cells. First a score for strength ofHistomorphologypositive staining was given: no colour was 0, lightyellow was 1, brown was 2, deep brown was 3. Sec-Gross findingsond a score for the percentage of positive cells wasTumors were round or multilobular, poorly circum-given: negative was 0, positive cells≤10% was 1,scribed, and having a size between 1x 2 x 2cm to511%~ 50% was 2, 51%~75% was 3, >75% was 4. Ifx 12x 16 cm. On section they were gray-yellow, andmultiplication of these two scores was >3, the immu-exhibited a rather variegated appearance with cystnohistochemical staining was considered to be posi-formation, hemorrhage, and necrosis.tive.Microscopic findings of the casesReverse transcriptase-polymeraseTwelve (29%) were biphasic type, 22(54%) werechain reaction (RT-PCR)monophasic fibous type and 7 (17%) were poorly dif-RNA cxtraction was conducted using a Trizol kit. Theferentiated type. Spindle-shaped cells were uniformPCR amplication primer sequences were: the forwardwith lttle cytoplasm, not well outlined, with ovalprimer (FP): 5'-CCAGCAGGCCTTATGGATA-3',dark-staining nuclei and oriented. Some areas ap-the reverse primer (RP): 5'-TTTGTGGGCCAGAT-peared with myxoid degeneration and hemangioperi-GCTTC-3', both lengths were 98 bp. Amplicationcytomatous vasculature changes (Fig. 1). Epithelialconditions: denaturation at 94C for 50 s, annealing atcells were oval, distinctly outlined, with abundant58C for 30 s and extension at 72C for I min, totallypale-staining cytoplasm and large vesicular nuclei,40 cycles. The PCR product was electrophoresed on aThey were disposed in solid cords, nests, or glandular3% agarose gel and stained with ethidium bromide.structures (Fig.2). Mast cells could obviously be seeninfiltrated in 8 cases (Fig3).Statistical analysisThe x test was conducted with SPSS statistical soft-Immunohistochemistryware, designed for the experimental groups.CK was cytoplasm positive (Fig.4). EMA was posi-tive in the cytoplasm or on the cell membranes. VimRESULTSwas cytoplasm positive (Fig.5). Des, a-SMA, s-100,PGP were all cytoplasm positive. PCNA was nucleiClinical datapositive.Statistical results showed that there were no signifi-The cases were comprised of 24 males and 17 fe-cant differences between the expression of CK andmales with a ratio of 1.4:1, ranging in ages 9 to 67EMA (P>0.01). Both could serve as antibodies foryears old, with an average of 35.4. The tumors oC-cured in the following locations: head neck 1 (2.4%),epithelial markers. On the contrary, there were signif-icant differences between the positive expression oftrunk 5 (12.3%), upper extremities 6 (14.6%), andlower extremities 29 (70.7%). Clinical complaintsDes, SMA, S- 100 and Vim, CK, and EMA (P<0.01),were localized palpable swelling or mass, associateddemonstrating that Des, SMA, s-100 are not the sig-nificant markers for synovial sarcomas.3中国煤化工Fig.1. Hemangiopericytomatous vasculature in synovial sarcoma (x200).JTYHC N M H Gidular in structure(x400). Fig.3. Myxoid degeneration area with mast cells itrated (x400).248 Chinese Journal of Clinical Oncology Aug. 2007, Vol.4, No.4 P 246~249 LingYang et al.Table 1. Results of immunobistochemistry and theDISCUSSIONpositive ratio expression.NegativePositivePositive ratio (%)Origin of the tumorsCK3687.8%Studies of molecular genetics have demonstrated thatEMA3:85.4%synovial sarcomas are a unique type of soft tissue tu-Vim041100.0%mor, with a chromosome translocation and formationofa SYT-SSX fusion gene'".Des4(2.5%SMA0.0%Pathological featuress-100314.6%According to the data from the Armed Forces InstitutePGP1075.6%of Pathology(AFIP), synovial sarcomas rank fourthPCNA3892.7%in malignant soft tissue tumors, but in China thesetumors rank second in malignant soft tissuc tumorsl21.In typical biphasic tumors, epithelial cells deposit inmass or have a trend for a glandular structure; thereare transformations between spindle cells and epithe-lial cellsl3I. Monophasic fibrous type tumors consistmainly of spindle cells, and epithelial cells are focalor almost absent; so careful examination and dissec-tion are required to make a diagnosjs. Theorically,monophasic epithelial type SSs exists, but they aredifcult to diagnose. In our study, poorly differenti-ated types accounted for 17%, lower than that whichhas been reported in the literature. DifferentationFig.4. CK positive expression in a glandular structure areabetween poorly differentiated and well differentiated(x200).SS is difficult. It is commonly regarded that if at least5 low scopes appear to be lowly differentiation41 orif there are 2 or more mitosis per HPF, it indicated apoorly differentiated tumor. In our study mast cellswere seen in 8 cases, for a positive ratio of 19.5%.Enzinger and Weiss suggested that"), mast cells areone characteristic of typical SS, appearing more inspindle cells areas, and it can be regarded as one ofthe important diagnostic bases for SS. In ss mesen-chymal, hemangiopericytomatqus changs also can beseen.Fig.5. Vim positive expression in a spindle cell area (x400).Immunohistochemical markersCK, EMA and Vim positive are sensitive markersRT-PCRfor diagnosis of SSI. In the biphasic type, Vim isUsing 20 cases of paraffin-embedded tumors withpositive in spindle cells areas, and CK or EMA areless hemorrbage and necrosis, (the samples withpositive in epithelial areas. In the monophasic fibroushemorrhage and necrosis were not examined in ordertype, CK or EMA can also be expressed in spindleto avoid contamination ), the expression of the SYT-cells areas, which demonstrate that the tumor cellsSSX fusion gene was detected in 18 cases (90%}.have a similarity to epithelial cells. s-100 is a markerTwo cases were negative (Fig.6).of nerve origin, and sometimes it is expressed in SS.Under such circumstances, there is a need to makea differential diagnosis from a malignant peripheralnerve sheath tumor (MPNST). In our study, the s-100-98bppositive ratio was 14.6%, lower than the 30% whichhas |中国煤化工research, s-100 hasFig.6. Results of detection of the SYT-SSX fusion gene. Laneshoeen PGP expressionA represented the marker. Lane B, C, D, F, G and H repre-inS IYHC N M H Gclei, and the laterissented samples. Lane E represented the negative control.regarded as all independent factor for the prognosis ofChinese Journal of Clinical Oncology Aug. 2007,Vol.4, No.4 P 246~249 Ling Yang et al.249SSI6. Y-box-binding protein (YB-1) is one part of theeosinophilic cytoplasm and SMA or Des are posi-DNA-binding protein family, which has all interac-tive. MPNST is of neural origin, so the spindle cellstion with inverted CCAAT boxes. YB-1 is thought toare more wave -shaped, and one end of the nucleis isbe associated with the repair of DNA and DNA injurybulged, and s- 100 is positive but epithelial markersreaction'7l.negative. Biphasic Ss must be differentiated frommalignant mesothelioma, which always occurs inMolecular characteristicsolder males who have had a history of contact withRecent findings have shown that all translocationsasbestos. These always are focused in the pleura orcloned from soft tissue tumors result in productionperitoneum, and furthermore by detection of the SYT-of typical-fusion gene proteins. These proteins haveSSX fusion gene they can be diagnosed. Hemangio-a relationship with tumor pathogenesis, but an un-pericytomatous also need to be differentiated fromderstanding of their biochemical role needs moreSS. These tumors have vascular changes in all of theresearch. Furthermore, many studies have showntumor area, are not focal, the tumor cells are polygonthat these fusion genes produced by chromosomein shape, CD34 positive, and negative for epithelialtranslocations are almost always transcription factors,markers.suggesting that the joint pathogenesis of SS may be aresult of disturbance of gene expression involved inREFERENCESgrowth and differentiation of the cells. The transloca-Enzinger FM, WeisV. Malignant)ft Tissue Tumortion of chromosome in SS is t (X;18) (p11.2; q11.2),of Uncertain Type. Soft tissue tumor. 4th ed, Louis:Mosby 2001;1483- 1509. .which results in the fusion between SYT of 18q11 and? Fang zW, Chen Y, Song JG, et al. Analysis of 796 casesSSX of Xpl1, thus a SYT-SSX fusion gene formed8).of soft tissue sarcomas. Chin」Clin Oncol 2006;33:87-90.In other tumors which require a histomorphologicaliy， Lai RQ. 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