Prognostic factors in synovial sarcoma.

The authors analyzed the prognosis in a population-based series of 24 patients with primary synovial sarcoma in the extremities (22) and trunk wall (two), all of whom were principally treated by surgery. No patient had evidence of metastatic disease at the time of diagnosis of the primary tumor. After 3 to 19 years of follow-up, six patients had developed local recurrence and 12 had died of metastatic disease including those six with local recurrence. All patients with tumors smaller than 4 cm were alive without evidence of disease, as were also four of the five patients who had larger tumors, but with a mitotic rate lower than 15 per 10 high-power fields. The association between local recurrence and metastatic disease may be more statistical than causal, since patients with both these events had more often larger tumors with a high mitotic rate.