Hello...my Wife self-discovered an abdominal mass that was eventually diagnosed as rLMS...retroperitoneal leiomyosarcoma. She had a recommeded CT scan which confirmed size and location, and was referred to a gynecological oncologist. While a regular gynecologist visit may begin the process, I'm sure she'll need to see a gynecological oncologist for confirmation and possible surgical options. There are a number of websites that provide info and a starting point. Try Googling "leiomyosarcoma" to get you started. There's also info here on the Mayo Sarcoma site as well as the general Mayo clinic site. Early detection and treatment options will be your best path now. Best of luck to you and your Daughter. It's overwhelming for sure, but there is help, hope and support out there. ❤️