Tehran University of Medical Sciences (TUMS) Academic Journal of Surgery 2423-3218 7 4 2025 01 04 101 106 Rhyan Saputra Department of Orthopedic and Traumatology, Oncology Division, Dr Moewardi General Hospital, Central Java, 57126 Dita Kusuma Department of Orthopedic and Traumatology, Oncology Division, Dr Moewardi General Hospital, Central Java, 57126 Zeno Baharano Department of Orthopedic and Traumatology, Sebelas Maret University 2024 07 17 Background: Synovial sarcoma is a rare malignant soft tissue tumor that commonly emerges in the para-articular area, with the knee as the predominant location. The preferred intervention for this tumor is still currently debated Case description: We presented a 29-year-old male with a very large mass in the right knee. The physical examination revealed impairment of the right lower extremities, particularly the knee. MRI confirmed the extent of the pathology, but the first pathology analysis was inconclusive. A wide resection was performed without prior neoadjuvant therapy. The second pathology analysis from the resected tissue confirmed the diagnosis of biphasictype synovial sarcoma. The patient was able to walk with no assistance, had an increased range of motion, and the utmost preservation of the limb. Conclusions: We presented a successful case of wide resection of synovial sarcoma with a promising clinical outcome. The complexity of the case leads to the need for a tailored approach that should be limited to musculoskeletal oncologists. https://ajs.tums.ac.ir/index.php/ajs/article/view/269