title: Malignant solitary fibrous tumor in retroperitoneum: A case report and literature review.
abstract: BACKGROUND
  Solitary fibrous tumor (SFT) is a rare mesenchymal tumor occurs in various sites. Malignant SFT in retroperitoneum is extremely rare.
  
  
  METHODS
  We report a case of malignant retroperitoneal SFT in a 59-year-old man presented with right flank pain for 1 month.
  
  
  METHODS
  A laparotomy and resection of the tumor were performed, the histopathologic and immunohistochemical findings were consistent with malignant retroperitoneal SFT. No adjuvant treatment was performed, and the patient had no signs of recurrence or metastasis at the 12 months follow-up.
  
  
  CONCLUSIONS
  Complete surgical excision is the basic treatment principle for malignant retroperitoneal SFT. The histologic features and the Ki-67 label index are helpful for the diagnosis of malignant SFT.
authors.affiliation: Department of Urology, The Third Xiangya Hospital of Central South University, Changsha, Hunan, China.
authors.forename: Yihong
authors.initials: Y
authors.lastname: Zhou
authors.forename: Xi
authors.initials: X
authors.lastname: Chu
authors.forename: Ye
authors.initials: Y
authors.lastname: Yi
authors.forename: Liang
authors.initials: L
authors.lastname: Tong
authors.forename: Yingbo
authors.initials: Y
authors.lastname: Dai
mesh_terms: D006801:Humans; D008297:Male; D008875:Middle Aged; D012186:Retroperitoneal Neoplasms / Q000473:pathology* / Q000601:surgery; D054364:Solitary Fibrous Tumors / Q000473:pathology* / Q000601:surgery