I just wanted to post my very recent experience of having two large dermoid cysts removed just to put people's minds at ease as I Googled until I found worst case scenario and was convinced I was either dying of cancer or going to have early menopause.
I am 30 years old without children and was first diagnosed as having a 5cm dermoid cyst on each ovary a few years ago but they were deemed too small to warrant an operation because I wanted children at some point and were forgotten about, having completely forgotten about them, I recently went to the doctors with pressure on my bladder especially around ovulation and was sent for an ultrasound which showed the cysts had grown significantly to 9cm and 10cm on each side. Despite wanting children and the rare risks involved e.g. infertility/early menopause, the risk of torsion/rupture along with the discomfort was too much for me so i opted to have them both removed. This has been done by open surgery due to their size and I am currently recovering fine, albeit sore! The surgeon managed to save about 10% of one ovary as more than expected was removed due to historic scarring and the other is completely fine. The reassuring thing is that even with a tiny bit of ovary left, hormones are still produced and early menopause can be prevented, it is super important to raise your initial concerns with the surgeon so they know to save tissue where possible. I also had the ovarian cancer protein screening through a blood test in advance so that he knew there were no issues there and wouldn't have to do a full removal if he saw anything unusual.
I totally understand what you are going through right now, I researched and thought the worst and was really worried about my future but surgeons can genuinely work miracles with the technology and knowlege they have access to, they would also have done the procedure by keyhole if it hadn't have been for their size and on both sides which is very rare.
I'm glad I pushed for this to be resolved ASAP as I can now move on with my life and look forward to my future, I hope you find the same quick resolution.
Good luck ladies and stay strong!!xx