Background Synovial sarcoma (SS) is a rare but aggressive soft tissue sarcoma that can be challenging to diagnose accurately, especially when it mimics more common conditions such as tuberculosis. This case report aims to highlight the diagnostic difficulties and emphasize the importance of early and accurate identification.Case Presentation A 23-year-old female patient presented with left-sided lumbar pain that progressively worsened over three weeks, accompanied by weakness and numbness in the left lower limb. She was misdiagnosed twice by two hospitals as having a spinal tuberculous abscess based on weakly positive anti-tuberculosis antibody and imaging findings. Despite continuous anti-tuberculosis treatment, her condition deteriorated. The first surgery revealed findings inconsistent with spinal tuberculosis, and a tumor could not be ruled out, but the pathological biopsy was inconclusive. A second surgery was performed to resect the mass and obtain a biopsy, which confirmed SS. Unfortunately, by this time, the disease had metastasized to her lungs, and she missed the optimal window for surgical intervention.Conclusion This case highlights the necessity of considering malignancies such as SS in the differential diagnosis of spinal lesions, especially when the clinical response to treatment is poor. Early diagnosis and intervention are crucial for improving patient outcomes. Our literature review thoroughly examines the characteristics of paraspinal SS and provides insights to prevent misdiagnosis. It emphasizes the importance of timely surgical intervention to improve patient survival.