Synovial sarcoma presenting as posterior tibial tendon dysfunction: a report of two cases and review of the literature.

Posterior tibial tendon dysfunction (PTIO) is a common disorder affecting the foot and ankle. In contrast, synovial sarcoma is uncommon. Because they often are slow growing, synovial sarcomas can be misdiagnosed as arthritis, bursitis, or synovitis. Synovial sarcoma also is one of the few soft-tissue tumors that can be painful. We describe two patients who had signs and symptoms similar to those of PTIO but had synovial sarcomas. They complained of pain and swelling of the medial foot and ankle. In addition, a review of the literature is presented for this unusual entity.