Molecular Profiling of SYT-SSX Fusion Transcripts for Enhanced Diagnosis of Synovial Sarcomas

<b>Background/Objectives</b>: Synovial sarcoma (SS) is an aggressive soft-tissue tumor characterized by the chromosomal translocation t(X;18) (p11.2;q11.2), most commonly involving the fusion of the <i>SYT</i> gene on chromosome 18 with the <i>SSX1</i> or <i>SSX2</i> genes on chromosome X. This study aims to explore the clinicopathological and molecular characteristics of synovial sarcoma in a cohort of Moroccan patients. <b>Methods</b>: We analyzed 48 cases of synovial sarcoma using formalin-fixed, paraffin-embedded (FFPE) tissue samples. Histological grading was performed according to the FNCLCC system. Immunohistochemical staining was employed to detect cytokeratin (CK) and epithelial membrane antigen (EMA). Molecular analysis included fluorescence in situ hybridization (FISH) to identify <i>SS18</i> gene rearrangements and reverse transcription-polymerase chain reaction (RT-PCR) to detect <i>SYT-SSX</i> fusion transcripts. <b>Results</b>: Among the cohort, 56% of cases showed <i>SS18</i> gene rearrangements via FISH, while RT-PCR confirmed the presence of <i>SS18-SSX1</i> and <i>SS18-SSX2</i> transcripts in 60% and 32% of cases, respectively. The remainder was classified as undifferentiated sarcoma. Notably, no significant associations were observed between <i>SYT-SSX</i> fusion type and clinicopathological features. <b>Conclusions</b>: These findings underscore the importance of integrating molecular techniques for precise diagnosis in synovial sarcoma. The results align with global patterns, emphasizing the necessity for molecular testing to enhance diagnostic accuracy and informing potential therapeutic advancements.