Synovial Sarcoma: Molecular Biology, Pathology, and Therapeutic Strategies

Synovial sarcoma (SS) is a malignant mesenchymal neoplasm with variable epithelial differentiation. SS is defined by the presence of a specific SS18::SSX fusion gene. Moreover, SS can occur at any age, shows no significant sex predilection, and most commonly arises in the deep soft tissues of the extremities, typically in juxta-articular locations (approximately 70% of cases), with a variable prognosis. SS accounts for 5–10% of all soft tissue sarcomas. Meanwhile, despite recent advances in diagnosis and therapy, SS remains a diagnostic and clinical challenge due to the associated broad anatomical distribution and diverse histological patterns. This review aims to provide a comprehensive update on the clinical, molecular, and pathological features of SS, with emphasis on diagnostic strategies and treatment approaches.