Cysts are so very, very common in younger women. If you check the top right of this page at "Health Pages" you will see a lot of information about cysts. They many times, are just part of the cycle and will resolve themselves on their own. I don't know how they could be so sure it was a cyst without another ultrasound.
She needs to make another appointment and have another ultrasound if she's in that much pain.Was that a transvaginal ultrasound? The problem with larger cysts is that they can twist or rupture and that is extremely painful.. Please don't worry about cancer at this stage of the game. There are a lot of other symptoms with Ovarian Cancer ; bloating, feeling of fullness, gastric problems, etc. Remember that 95 % of all cysts are benign...
Take care,
Sandy
It is very scary not knowing what's going on inside your body. I have been dealing with ovarian issues for years and it is very nerve wrecking so I can relate. I hope your daughter is all right and that she is healthy. God Bless!