<aside>
Solitary fibrous tumor (SFTs) are rare mesenchymal neoplasms characterized by spindle cell proliferation in association with a network of thin branching vessels (staghorn).
https://doi.org/10.1016/j.ejrad.2021.110053
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It includes what was previously classified as hemangiopericytoma (HPC), now unified under SFT/HPC spectrum per the WHO 2021 CNS Tumor Classification.
Molecular features:
| Feature | Details |
|---|---|
| Cell of origin | Mesenchymal (fibroblastic/myofibroblastic) |
| Genetic hallmark | NAB2–STAT6 gene fusion (pathognomonic) |
| Immunostaining | STAT6 nuclear positivity, CD34+, BCL-2+, CD99+ |
| WHO Grades | – Grade 1: Benign (classic SFT) |
| – Grade 2: Intermediate cellularity | |
| – Grade 3: Malignant (former hemangiopericytoma, high mitotic index) |
<aside>
Solitary fibrous tumor (SFT) is composed of spindled to ovoid cells in a patternless architecture with prominent stromal collagen and hemangiopericytoma-like vessels.
https://doi.org/10.1038/modpathol.2013.164
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| Feature | Description |
|---|---|
| Classic SFT | Spindle cells with collagenous stroma, staghorn vasculature |
| High-grade SFT / HPC | Increased mitoses, necrosis, cellularity, nuclear pleomorphism |
| IHC Markers | STAT6 nuclear staining, CD34+, BCL-2+, CD99+, vimentin+ |
https://doi.org/10.3390/cancers13122913
https://www.actasdermo.org/es-cutaneous-solitary-fibrous-tumor-a-articulo-S1578219017304316
https://doi.org/10.1186/s13000-021-01095-2
https://doi.org/10.3390/cancers13102470
https://doi.org/10.1038/modpathol.2012.83
https://doi.org/10.3389/fsurg.2024.1332421
| Feature | Details |
|---|---|
| Incidence | Rare |
| Age | Middle-aged adults (40–60 years) |
| Sex | Slight male predominance |
| Sites | Pleura, meninges, retroperitoneum, pelvis, orbit, soft tissue |