【How-to】How much does a 15 cm ovarian cyst weigh

But some cysts can grow to be very big, like the size of a watermelon,” says Dr Eloise Chapman-Davis, a gynaecological oncologist at Weill Cornell Medicine and New York-Presbyterian. “Many women will write that off as weight gain, but abdominal pain and bloating could be the result of a mass growing in the stomach.”