Disease Definition: Solitary fibrous tumor (SFT), also known as fibrous tumor of the pleura, is a rare mesenchymal tumor originating in the pleura or at virtually any site in the soft tissue including seminal vesicle. Approximately 78% to 88% of SFT's are benign and 12% to 22% are malignant. It is a heterogeneous group of rare spindle-cell tumors that include benign and malignant neoplasms. Their cell of origin is still debated. SFT is preferred by most pathologists as a better term than “hemangiopericytoma” that gathers numerous unrelated entities and is presently only employed by neuropathologists. We focus the present paper on the forms of this family of tumors occurring in adult patients. There are 3 typical primary locations: pleural, meningeal and extrathoracic soft tissue.
Disease Symptoms: Patients present with proptosis and possibly ptosis, eyelid swelling, tearing, diplopia or decreased vision. Malignant infiltrating lesions can sometimes cause pain.
Disease Treatment: Because even benign-appearing solitary fibrous tumors (SFTs) can be locally recurrent and metastatic, wide resection of both benign and malignant SFTs is recommended. Preoperative vascular studies and arterial embolization should be considered because of the known bleeding risk with resection. 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. No evidence suggests that adjuvant chemotherapy is beneficial. If the SFTR appears malignant histologically, adjuvant radiation therapy may be considered. Long-term follow-up is recommended because local and distant relapse is possible, even with benign-appearing tumors.
Statistics: The current four patients were two males and two females, ranging from 17 to 60 years of age. Magnetic resonance imaging scans of the current patients showed inhomogeneous low to intermediate intensity signal on T1-weighted images and inhomogeneous intermediate to high intensity signal on T2-weighted images. Histologically, the tumors were composed of a haphazard proliferation of spindle cells, although cellularity was variable in each case. Two of the four tumors showed hypercellularity of spindle cells with focally myxomatous or hyaline changes, whereas myxomatous patterns with scattered spindle cells throughout the specimens were observed in the other two tumors. Immunohistochemically, all four patients showed positive immunoreactivity for CD34, and two tumors showed focally positive immunoreactivity for bcl-2 protein. During the followup of 12 to 54 months, neither local recurrence nor distant metastasis was detected after wide resection.