[Detection of SYT-SSX fusion gene in paraffin-embedded tissues and its clinicopathologic significance for synovial sarcoma].
OBJECTIVE
To investigate the feasibility of detecting SYT-SSX fusion gene in paraffin-embedded tissues and its diagnostic significance for synovial sarcoma (SS).


METHODS
Formalin-fixed, paraffin-embedded samples of 38 cases of SS and 40 cases of control tumors (including spindle cell sarcoma and metastatic adenocarcinoma) were retrived from archival materials. SYT-SSX fusion transcripts were detected in all samples by RT-PCR. House-keeping gene Porphobilinogen Deaminase (PBGD) was used to detect the quality of mRNA.


RESULTS
PBGD mRNA was detected in 64 of the 78 tumor cases (82.1%). SYT-SSX fusion transcripts was detected in 33 of the 38 synovial sarcoma specimens. No SYT-SSX mRNA expression was found in control tumors. SYT-SSX mRNA expression rate reached 89.2% (33/37) in synovial sarcomas after exclusion of 1 case which was negative for both SYT-SSX and PBGD. In 33 SYT-SSX positive synovial sarcomas, 22 had SYT-SSX1 and 6 had SYT-SSX2 fusion transcripts. In 5 cases, the fusion type could not be distinguished. There was an association between SYT-SSX fusion type and histologic subtype. All 10 biphasic synovial sarcoma cases had the SYT-SSX1 fusion, whereas 12 of 18 monophasic synovial sarcoma had the SYT-SSX1 and 6 had the SYT-SSX2 fusion gene (P < 0.05).


CONCLUSIONS
(1) Detection of SYT-SSX fusion gene in paraffin-embedded tissues was found to be a sensitive and specific method for the diagnosis and differential diagnosis of synovial sarcoma. (2) There was an association between SYT-SSX fusion type and histologic subtype.SYT-SSX2 fusion transcript could only be found in monophasic synovial sarcomas.
Wei
Y
Y
Department of Pathology, Cancer Hospital, Fudan University, Shanghai 200032, China.
Sun
M
M
Zhu
H
H
Xu
Z
Z
Wang
J
J
Zhu
X
X
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019677:Artificial Gene Fusion; D001483:Base Sequence; D002648:Child; D005260:Female; D015870:Gene Expression; D006801:Humans; D011163:Hydroxymethylbilane Synthase / Q000235:genetics; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D016612:Paraffin Embedding; D012333:RNA, Messenger; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013584:Sarcoma, Synovial / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology
D015514:Oncogene Proteins, Fusion; D012333:RNA, Messenger; C116512:SYT-SSX fusion protein; D011163:Hydroxymethylbilane Synthase