Hi. My Mom Showed Signs Of Abdominal Distension. An Ultrasound

Hi. My mom showed signs of abdominal distension. An ultrasound revealed a large multiseptated polycystic mass occupying her abdomen and pelvis. She got her CT scan done today. Results will be in tomorrow. She survived breast cancer 8 years ago. There's a family history of breast, uterine, and ovarian cancers. She is 59 years old. I'm just worried about the prognosis... Could this be something benign?