Figure 17b. Determining the origin of pelvic masses in a 32-year-old woman. CT scans show a complex cystic mass in the left lower pelvis, which was identified as ovarian because of its location medial to the ureter (U in a) and by recognizing the attachment of the suspensory ligament (SLA) to the mass. A structure in the right lower pelvis contains a small cystic mass; this structure was also medial to the ureter (not shown) and was confirmed to be the ovary (Ov in b) because the suspensory ligament (SL) leads to it. The bilateral cystic lesions proved to be endometriomas. ULM = uterine leiomyoma pedunculated from the fundus.