Mediastinum
Soft tissue tumors
Solitary fibrous tumor
Author: Hanni Gulwani, M.B.B.S.
Topic Completed: 1 December 2012
Minor changes: 20 November 2019
Copyright: 2003-2019, PathologyOutlines.com, Inc.
PubMed Search: Solitary fibrous tumor mediastinum
Table of Contents
Definition / general | Case reports | Gross description | Microscopic (histologic) description | Positive stains | Negative stains | Electron microscopy descriptionCite this page: Gulwani H. Solitary fibrous tumor. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/mediastinumSFT.html. Accessed March 4th, 2021.
Definition / general
- Usually pleural but also elsewhere and in mediastinum
- No association with asbestos
- Either no symptoms or symptoms of mass effect
Case reports
- 18 year old man with 6 cm tumor (Gen Thorac Cardiovasc Surg 2010;58:205)
- 62 year old woman with stridor and a mass (Tumori 2007;93:508)
- 64 year old man with en bloc resection of malignant tumor (J Thorac Oncol 2008;3:1068)
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
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
