1.Detection of SYT-SSX mutant transcripts in formalin-fixed paraffin-embedded sarcoma tissues using one-step reverse transcriptase real-time PCR
Norlelawati AT ; Mohd Danial G ; Nora H ; Nadia O ; Zatur Rawihah K ; Nor Zamzila A ; Naznin M
The Malaysian Journal of Pathology 2016;38(1):11-18
Background: Synovial sarcoma (SS) is a rare cancer and accounts for 5-10% of adult soft tissue
sarcomas. Making an accurate diagnosis is difficult due to the overlapping histological features of SS
with other types of sarcomas and the non-specific immunohistochemistry profile findings. Molecular
testing is thus considered necessary to confirm the diagnosis since more than 90% of SS cases carry
the transcript of t(X;18)(p11.2;q11.2). The purpose of this study is to diagnose SS at molecular level
by testing for t(X;18) fusion-transcript expression through One-step reverse transcriptase real-time
Polymerase Chain Reaction (PCR). Method: Formalin-fixed paraffin-embedded tissue blocks of 23
cases of soft tissue sarcomas, which included 5 and 8 cases reported as SS as the primary diagnosis
and differential diagnosis respectively, were retrieved from the Department of Pathology, Tengku
Ampuan Afzan Hospital, Kuantan, Pahang. RNA was purified from the tissue block sections and
then subjected to One-step reverse transcriptase real-time PCR using sequence specific hydrolysis
probes for simultaneous detection of either SYT-SSX1 or SYT-SSX2 fusion transcript. Results:
Of the 23 cases, 4 cases were found to be positive for SYT-SSX fusion transcript in which 2 were
diagnosed as SS whereas in the 2 other cases, SS was the differential diagnosis. Three cases were
excluded due to failure of both amplification assays SYT-SSX and control β-2-microglobulin. The
remaining 16 cases were negative for the fusion transcript. Conclusion: This study has shown that
the application of One-Step reverse transcriptase real time PCR for the detection SYT-SSX transcript
is feasible as an aid in confirming the diagnosis of synovial sarcoma.