Solitary fibrous tumor of the mediastinum.

An 18-year-old man was referred to our hospital for further evaluation of a right anterior mediastinal tumor that measured 6 cm in diameter. Computed tomography-guided transcutaneous aspiration biopsy was performed, but no definitive diagnosis could be obtained. Because the tumor did not appear to be a high-grade malignant tumor, we undertook resection of the tumor to obtain a definitive diagnosis and provide appropriate treatment. Total thymectomy with tumor resection was performed through a median sternotomy. The tumor was solid, measuring 5.2 x 4.2 x 3.5 cm. The histological diagnosis was solitary fibrous tumor (SFT) arising from the mediastinum. Most extrathoracic SFTs appear to pursue a benign course, although careful long-term follow-up of these patients is necessary because the tumors have been reported to recur or metastasize in some cases.