- Human pathology

Home > E. Pathology by systems > Urinary system > Kidneys > renal solitary fibrous tumor

renal solitary fibrous tumor

Friday 25 November 2005

renal SFT

Definition: Solitary fibrous tumor (SFT) is a neoplasm that can occur in the urogenital tract, and is also reported occurring in the spermatic cord, seminal vesicles, urinary bladder, prostate, and kidney.


- proliferation of bland-looking vimentin+, CD34+, bcl2+ and CD99+ spindle cells
- haphazard growth pattern
- storiform growth pattern, pushing borders
- low mitotic rate (2 mitoses x 10 HPF)

Differential diagnosis

- other primary monomorphous benign and malignant spindle cell tumors of the kidney

  • fibroma
  • benign fibrous histiocytoma
  • hemangiopericytoma
  • inflammatory myofibroblastic tumor
  • leiomyoma
  • angiomyolipoma with predominant spindle cell smooth muscle component
  • benign peripheral nerve sheath tumors
  • renal mixed epithelial/stromal tumors
  • adult type mesoblastic nephroma
  • fibrous type monophasic synovial sarcoma
  • malignant peripheral nerve sheath tumors
  • adult-type fibrosarcoma
  • low-grade fibromyxoid sarcoma

Molecular biology

- A GRIA2 and PAX8-positive renal solitary fibrous tumor with NAB2-STAT6 gene fusion. (26337721)

Open references

- A GRIA2 and PAX8-positive renal solitary fibrous tumor with NAB2-STAT6 gene fusion. Ichiyanagi O, Ito H, Takai S, Naito S, Kato T, Nagaoka A, Yamakawa M. Diagn Pathol. 2015 Sep 4;10(1):155. doi : 10.1186/s13000-015-0386-x PMID: 26337721 (Free)


- Magro G, Cavallaro V, Torrisi A, Lopes M, Dell’Albani M, Lanzafame S. Intrarenal solitary fibrous tumor of the kidney report of a case with emphasis on the differential diagnosis in the wide spectrum of monomorphous spindle cell tumors of the kidney. Pathol Res Pract. 2002;198(1):37-43. PMID: 11866209