Dedifferentiated solitary fibrous tumor of the kidney: A case report

The kidney is a relatively rare site for solitary fibrous tumors (SFTs). Previously, rare cases of SFT with dedifferentiation that showed an abrupt transition between low- and high-grade areas, similar to other dedifferentiated sarcomas, have been described. Herein, we report the case of a 75-year-old man who presented with gross hematuria. Computed tomography revealed a left renal tumor; a laparoscopic left nephrectomy was performed. The tumor was pathologically diagnosed as dedifferentiated SFT of the kidney. Dedifferentiated SFT may have worse prognosis than conventional SFT. Although this patient has been disease-free for 7 months, careful long-term follow-up is still required.