Femoral Vein Intravascular Synovial Sarcoma Mimicking Primary Deep Vein Thrombosis—A Rare Cause of Deep Vein Thrombosis

Abstract Synovial sarcomas are rare malignant mesenchymal soft tissue tumors. We presented the case of a 53-year-old woman patient presenting with acute deep vein thrombosis, later diagnosed as synovial sarcoma femoral wall. The tumor was identified through cross-sectional magnetic resonance angiography and computed tomography, followed by ultrasound-guided core biopsy. report emphasized importance considering possibility an intravascular neoplasm mimicking thrombus, particularly if calcifications, expansion cystic spaces, fluid–fluid levels, septations within thrombosed seen in imaging.