Clinical,radiological and pathological diagnosis of renal solitary fibrous tumor(Report of 2 cases and review of literature)

Objective:To study the clinical,radiological,pathological features and differential diagnosis of solitary fibrous tumor(SFT)of kidney,to improve the diagnosis level of the tumor.Method:Two cases of renal SFT were analyzed from the clinical symptoms,radiological data and pathological features,and with related literature reviewed.Result:Two tumors all occurred in left kidney,one origin from the renal parenchyma,the other one origin closely related to pelvis,which was clinically and radiologically thought to be renal cell carcinoma and underwent left radical nephrontectomy.Grossly,the tumor was a well-circumscribed,with lobular or spherical mass,without necrosis or hemorrhage.Microscopically the bland spindle cells proliferated with the vortex-shaped or irregular-shaped arrangement,part of the collagen fibers mixed,in part showed hemangiopericytoma-like structure and were accompanied by hyalinized collagenous tissue.Immunohistochemical analysis showed that the tumor cells were diffusely positive for CD34 and CD99,negative stain for S100,SMA,CKpan,P63 and HMB45.From the characterized CD34,CD99 positive stain,two case were diagnosed as SFT and no tumor recurrence and metastasis with 6 months follow-up.Conclusion:Renal SFT is a very rare disease and often misdiagnosed as renal cell or pelvis carcinoma,immunohistochemical CD34 positive stain is characterized in this tumor,radical resection and long term follow-up is necessary for the treatment of this kind of tumor.