Mediastinum
Other benign / low grade tumors
Solitary fibrous tumor

Author: Hanni Gulwani, M.D. (see Authors page)

Revised: 18 June 2018, last major update December 2012

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Solitary fibrous tumor mediastinum

Cite this page: Gulwani, H. Solitary fibrous tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/mediastinumSFT.html. Accessed November 21st, 2018.
Definition / general
  • Usually pleural but also elsewhere and in mediastinum
  • No association with asbestos
  • Either no symptoms or symptoms of mass effect
Case reports
Gross description
  • Firm, gray-white cut surface, well demarcated from adjacent tissue
  • May resemble uterine leiomyoma
  • Often polypoid protrusions from pleural reflections or derived from soft tissue between the lungs
Microscopic (histologic) description
  • Bland spindle cells arranged haphazardly in fibrohyaline stroma resembling keloid
  • Abundant thick walled blood vessels, often with staghorn appearance
  • May have mesothelial lining
  • Usually few mitotic figures but may have up to 10 per 10 HPF
  • Occasional myxohyaline degeneration, storiform growth, nuclear pleomorphism, marked cellularity; no necrosis
Positive stains
Negative stains
Electron microscopy description
  • Nondescript spindle cells with prominent rough endoplasmic reticulum, focal intrareticular collagen fibers
  • No features of myofibroblasts, smooth or skeletal muscle, epithelial differentiation