Nonoperative Therapy
No evidence suggests that adjuvant chemotherapy is beneficial. In nondedifferentiated SFTs, antiangiogenic agents appear to be more effective than chemotherapy. Pazopanib is recommended as first-line antiangiogenic therapy on the basis of its favorable toxicity profile and the efficacy derived from a phase II trial. [2] At the time of progression, rotating antiangiogenics is a reasonable approach. Other antiangiogenics, such as sunitinib and axitinib, have demonstrated activity in SFT and could be used sequentially.
If the SFT appears malignant histologically, adjuvant radiation therapy (RT) may be considered.
Surgical Therapy
Because even benign-appearing solitary fibrous tumors (SFTs) can be locally recurrent and metastatic, wide resection is recommended for both benign and malignant SFTs. Preoperative vascular studies and arterial embolization should be considered because of the known bleeding risk with resection. [3, 15] Careful exclusion of other diagnoses (eg, synovial sarcoma) is important. Because of the favorable outcome with SFTs, it may be possible to avoid limb-threatening and deforming operations. [5]
Long-term follow-up is recommended because local and distant relapse is possible, even with benign-appearing tumors.
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MRI of solitary fibrous tumor demonstrates a deep soft-tissue mass in the anteromedial aspect of the thigh with heterogenous high signal intensity on coronal STIR imaging.
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Similar signal intensity as skeletal muscle on precontrast axial T1-weighted fat-suppressed turbo-spin echocardiography.
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Intense uptake on postcontrast comparison images.
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Histology of solitary fibrous tumor demonstrates a bland cell morphology and staghorn-type branching of vessels on low magnification of hematoxylin and eosin stained slides. Image courtesy of Paul E. Wakely, Jr, MD.
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Histology of solitary fibrous tumor demonstrates a bland cell morphology and staghorn-type branching of vessels on high magnification of hematoxylin and eosin stained slides. Image courtesy of Paul E. Wakely, Jr, MD.
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Positive staining for CD34. Image courtesy of Paul E. Wakely, Jr, MD.
