Primary Solitary Fibrous Tumor of the Forearm With Frequent Late-Onset Recurrence in the Pleura.

Solitary fibrous tumor (SFT) is a relatively rare form of mesenchymal tumor that generally has a benign clinical course. However, SFTs have malignant potential. We report the case of a 36-year-old man with local relapse and frequent late-onset pleural metastasis of primary SFT of the forearm. Pleural metastasis was first seen 11 years after the initial operation. During a 17-year period, he underwent 5 surgical resections. He has been free of disease for 61 months since the most recent operation.