Synovial sarcoma arising from the chest wall: MR imaging findings.

We report a case of synovial sarcoma of the chest wall in a 41-year-old man. Chest CT revealed a huge tumor of the left chest wall with heterogeneous enhancement. On MR imaging, the tumor showed the "bowl-of-fruit" mixed-signal appearance with fluid-fluid levels similar to those of synovial sarcoma of the extremities. Synovial sarcoma arising from the chest wall is extremely rare; only four cases have been reported in the English literature. As synovial sarcoma is considered a carcinosarcoma-like tumor with true epithelial differentiation, it is able to originate from various regions. Even if the tumor is found in a region distant from the synovial membrane, the differential diagnosis of a tumor which demonstrates such findings on MR imaging should include synovial sarcoma.