Clinicopathological analysis of solitary fibrous tumors

Objective To assess the clinical,histopathological and immunohistochemical characteristics of the solitary fibrous tumor(SFT),and to discuss its origin and differential diagnosis.Methods Twenty-seven cases of solitary fibrous tumor were analyzed by clinical and histological observation,and immunohistochemical staining of CD34,Vim,CD99,Bcl-2,Des,SMA,CK,EMA,CD68,CD-117,S-100 protein was examined.Results In 27 cases SFT lesions were found in lung,thoracic cavity,abdomen,mediastinum,fossa orbitalis,conjunctiva,hypoglossis,cervical vertebrae,forefinger,pelvis,groin,spermatic cord,scrotum,thigh and so on.The size of tumors ranged from 0.8 cm×0.6 cm×0.5 cm～30 cm×20 cm×8 cm.The majority of patients had some symptoms due to compression from the large tumor.Most cases,separated by strands of rope-like collagen,showed haphazard growth pattern of short spindle cells presenting a storiform,fascicularor or spiral pattern in some areas.Immunohistochemically overexpresstion of CD34,Vim,CD99 was observed in all cases;positive Bcl-2 was showed in 23 cases,CD117 was detected focally in 2 cases;SMA and Des were detected focally in 1 case;CK,EMA,CD68 and S-100 proteins were negative.Twenty-one patients were followed up for 3~92 months and all were alive without recurrency or metastasis.Conclusions The diagnosis of SFT is based on histopathology and immunohistochemistry.Patients with SFT have a good prognosis after tumor removed completely.