RESUMEN
OBJECTIVE@#To determine the CT imaging features for retroperitoneal solitary fibrous tumor (SFT). @*METHODS@#The imaging features of CT for 2 SFT cases, confirmed by pathological examination, were retrospectively analyzed and compared with pathological results. @*RESULTS@#The results of CT showed that retroperitoneal SFTs were large, well-defined and consisted of solid components with different density (equal or low). In the scan of contrast enhancement, tumors were strongly enhanced, and the multiple vascular shadows were seen in the tumor at arterial phase. There was progressive enhancement from the arterial to venous phase, and capsule of tumor was 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 positive immunohistochemical staining for CD34 and bcl-2. @*CONCLUSION@#The retroperitoneal SFT possesses a definite characteristic in CT imaging features, and the diagnosis can be confirmed by histopathology and immunohistochemistry.