CT imaging features of retroperitoneal solitary fibrous tumor(report of 2 cases and literature review)

Objective To investigate the CT imaging features of retroperitoneal solitary fibrous tumor(SFT).Methods CT findings in 2 cases with SFT confirmed by histopathology and immunohistochemistry were reviewed retrospectively,and compared with pathological results.Results CT findings of retroperitoneal SFT were large,well-defined and smooth contour of masses and it was consisted of solid components of two different density.On enhanced CT scans,tumors showed strongly enhancing,the multiple vascular shadows were seen within the tumor in arterial phase.There was progressive enhancement from the arterial to venous phase,and capsule of tumor can be displayed.Histologically,the tumors were composed of spindle cells within a background of collagen stroma,and showed a wide range of growth patterns,alternating hypercellular(tumor cell–rich)and hypocellular(collagen-rich)areas.The diagnosis was confirmed by characteristic positive immunohistochemical staining for CD34.Conclusion The retroperitoneal SFT possesses a definite characteristic in CT imaging findings,the diagnosis is depended on histopathology and immunohistochemistry.