Fig. 3.

Axial contrast-enhanced T1 fat saturated images of the perineum (A) and pelvis (B), coronal T2-weighted fat saturated image (C), and axial proton density weighted image (D) of the pelvis. The tumor is seen extending from the left ischioanal fossa (thin arrow, (A)), through the levator ani muscle, into the pelvis (thin arrows, (B), (C), and (D)). The mass demonstrates marked enhancement and has internal low-intensity “swirled” signal on all image sequences. Adjacent structures, including the urinary bladder (curved arrows) and uterus (thick arrow), are shifted to the right but are not invaded by the tumor.