Synovial sarcoma of the stomach: case report and systematic review of the literature.

Synovial sarcoma is a rare mesenchymal malignant neoplasm that presents a specific t(X;18) translocation forming SS18(SYT)-SSX chimera gene. It is most commonly seen in soft tissues of the extremities. The digestive tract is an exceptional site of involvement. We report a case of primary gastric synovial sarcoma in a 48-year-old female. Differential diagnosis of synovial sarcoma from other spindle cell, mesenchymal and cytokeratin-positive tumors is critical for the treatment and prognosis. Immunohistochemistry studies and molecular analysis are required to settle a proper diagnosis.