It is serious enough that a 10 yr old has to go through surgery and it must be a very large size for them to be doing that. How big is the cyst? There is no way to tell what it is until she has her surgery. Are they doing laprascopic surgery or are they doing regular surgery? That might tell us something about the size of the mass. She is very young to be getting cysts. Has she started menstruating yet? I wish I had some answers for you. If it is any consolation, 99% of all ovarian masses are benign and the odds that a 10 yr old has OVCA, (while not impossible) are astronomical. I will be praying for your cousin and your family. I know this is a very scary time. It is not easy for us adults who have to go through surgery, but for a 10 yr old it must be really frightening. Take care and please let us know how it turns out Tuesday.
I don't have any other info about the cyst beyond what Jan has posted.
I did have surgery when I was 9 for a bowel resection.
Now adays everything is very well controlled. Just make sure that her pain is managed properly. If she is being treated at a Children's Hospital, most attitudes tward pain management are appropriate. If she is at a regular hospital, just make sure you don't get anyone with the attitude "kid's don't feel pain like we do'. Yes, some people in the medical field have this attitude.
There is a topical cream that can be applied to the skin about 20 minutes before iv insertion to dull the pain. Make sure she gets it. After that, they'll give her the 'giggle juice' (med in the iv) and she won't feel scared...just silly.
Sometimes they will even gas the kids out, then start the iv so they don't feel any pain. When they do this, they give them the 'giggle juice' by mouth. since it's such a tiny amount, anesthesia usually isn't concerned with it.
When she wakes up, she should be properly medicated so she won't feel any pain. Maybe just a little when she tries to sit up in bed, but nothing constantly irritating.
I don't remember being scared before my surgery as a child. I just remember feeling releived that the pain would be over when I woke up, as I was told.
Bless her heart.