Solitary fibrous tumor arising from hyperplastic thymus

One case of a solitary fibrous tumor arising from the hyperplastic thymus is recorded. The patient was a 37-year-old female who presented with an anterior mediastinal mass. Thoracotomy was performed and revealed that the tumor arose on a pedicle from the posteroinferior surface of the enlarged thymus. The pathologic findings were characteristic of a solitary fibrous tumor. This is a very rare neoplasm that occurred in the mediastinum and had evidence of thymus gland in origin.