I'm sorry it took so long to get this looked at. Most ovarian cysts, even complex ones, are benign so you should not need to lose your ovary. We need all our female parts our whole lives for good health. Studies have shown removal of even one part - an ovary, ovary, the uterus even Fallopian tube - has negative effects on our long-term health and well-being. Unfortunately, removal of women's sex organs is grossly overused. About 90% of hysterectomies (uterus removals) and oophorectomies (ovary removals) are unnecessary.
How big is the cyst and what exactly does the MRI report say? Imaging is not exact so cysts are not always the type they appear to be. Most cysts resolve on their own, no intervention / surgery needed. The CA125 test is not accurate at diagnosing ovarian cancer. Benign conditions, including harmless ovarian cysts, can cause elevated results. I'm surprised they even did a CA125.
If you do indeed need surgery, the frozen section done while you are in the operating room should dictate whether or not the ovary needs to be removed. If it's not cancerous (only about 13 out of 1,000 women get ovarian cancer) you would not need your ovary removed. In order to protect your organs, you will want to specifically state on the surgical consent form what can and cannot be removed under what conditions. Be sure you get the consent form days prior to surgery and that any revisions you make are signed off on by your surgeon. Keep a copy of the final. Most gynecologic consent forms are open ended allowing the surgeons to remove whatever part(s) they want. Hard to believe but true.
Doctors with good cystectomy (cyst removal) skills can almost always remove ovarian cysts and preserve the ovary or enough of it for normal function. It may be more difficult to find a doctor who will do a cystectomy than an oophorectomy (ovary removal) because it takes a little more skill and time and I've read it typically doesn't pay any better. I have read of at least one situation where a woman had to go outside her insurance network to get a surgeon who would do a cystectomy and she had to fight her insurance company to get the cystectomy. This website is helpful in understanding ovarian cysts - http://ovaryresearch.com/ovarian_cysts.htm.
Please keep us posted. I wish the best for you.
These are scary things going on and am sure you are anxious. You are working with your doctors and I'm glad of that. It is indeed true that other things can elevate the ca125 but yours is definitely high. The following list are things that can elevate the CA 125.
Pelvic inflammatory disease
The first trimester of a pregnancy
For my mother in law with ovarian cancer, the CA 125 was used to monitor her to see disease progression. But it's not the most reliable test. I think you are very wise to follow up though as the elevated numbers give pause and make you dig deeper.
I've had my own cancer scare and I know it's terrifying. I didn't have cancer. :>)) Let us know what happens next!