Clinical behavior of solitary fibrous tumor: a retrospective review of 30 patients.

BACKGROUND: Solitary fibrous tumors (SFTs) are a rare type of soft tissue sarcoma of unpredictable clinical behavior. Some clinicopathologic characteristics have also been related to patient outcome.

METHODS: This study is a retrospective review of 30 patients. We analyzed the clinical course and pathological factors to predict recurrence.

RESULTS: The mean age was 55.9 years. Forty-five percent were located in the thoracic region. The mean tumor size was 10 cm (max24). Thirty-three percent had a relapse and 20 % have died. Median time to relapse was 7.18 (1-13) years. Median overall survival (OS) was 15.5 years (0-32). On histopathologic analysis, 6 % percent had >4 mitoses, 23 % had necroses, and 36 % had atypia/pleomorphism. Forty-three percent had tumor size >10 cm. Forty-six percent had at least one characteristic of malignancy. None of this data could predict clinical behavior by itself.

CONCLUSIONS: SFT can be an aggressive disease and relapses can occur several years from diagnosis. We did not find any clinicopathologic factors that could predict the tumor behavior accurately. Nevertheless, it should be consider that we included different tumor locations and the sample size is small.