Synovial sarcoma accounts for about 10% of adult soft tissue sarcomas, with 80–90% located in the limbs. Gastrointestinal tract involvement is rare. Synovial sarcoma has a propensity for local recurrence and lung metastases, which can be delayed beyond 5 years. The t(X;18) translocation resulting in the expression of a SYT–SSX fusion protein is commonly seen. Demonstration of this type of genetic rearrangement by fluorescence in situ hybridization or PCR is fundamental to the diagnosis of synovial sarcoma in unusual sites. Owing to the rarity of this tumor in the gastrointestinal tract, the appropriate method and extent of surgical resection is uncertain.