Dear Jason,
I agree with Islander. If your girlfriend has a 6 cm ovarian cysts and is having pain, she should ask her doctor about looking at the cyst by surgery. most cysts are benign but they can cause pain if they get over 4 cm in size.
best wishes
I look forward to the answer you get. All I know is that they can not tell if its cancer until they are in there. They take a peak, biopsy it and if its cancer take whatever needs to be removed out. I have a solid complex lesion / mass around the same size. Just had my obgyn oncologist appointment today and they will schedule me for the surgery to do just what I mentioned.
From what I have read around this forum you want to have an obgyn onc work on you. This way if it is cancer they can take care of it them and not have to reschedule for another surgery. Good luck to her!
I should also mention she has lower back pain as well.