Calcifying synovial sarcoma.

Analysis of the clinicopathological features and the available follow-up data in 32 patients with extensively calcified synovial sarcoma revealed an age incidence and anatomic distribution similar to that of ordinary synovial sarcomas without or with minimal calcification, but indicated a more favorable survival. The median age of 32 patient in this series was 26 years; the predominant location of the tumor was the soft tissues of the lower extremities; its average size was 4.6 cm (range, 1.5-20 cm). All of the tumors showed a focal biphasic cellular pattern and exhibited roentgenographic or microscopic evidence of extensive calcification and/or osseous metaplasia. Of the 26 patients with follow-up information (average 8.9 years) 17 were alive and well and six had died of their diseases, two after 7 and 19 years. Three additional patients were living with no signs of disease 1 1/2, 2 1/2, and three years after diagnosis, respectively. The five-year survival rate of 82.6 percent of this series is considerably better than the reported five-year survival rates of synovial sarcoma which range from 25-51%.