Figure 1

Retroperitoneal solitary fibrous tumor in a 22-year-old woman. (A) Solid part of the tumor in arterial phase is in moderate, uneven enhancement with extensive vessel, and unenhanced low-density cystic areas are visible inside. (B) The solid part of the tumor in the venous phase is insignificant, with uneven or no enhancement in low-density cystic areas, but envelope enhancement is visible. (C) Tumor cells with admixed thin and thick, collagen fibers. There is a relative demarcation between the hypercellular and hypocellular areas under the microscope.