Not sure about the theory on the vascular hook up or how they could tell...what test did you have to find the cyst? Ultrasound, CT, MRI?? An MRI would be the most comprehensive and give the most accurate results. BUT a complex cyst could still be a LOT of things and cancer doesn't have to be one of them. What is the rest of your GYN history like? Theoretically your chances of it being ovarian cancer are very small if you are not menopausal. It increases with lack of estrogen production. Family histroy also plays a part. Complex cysts could contain any number of things. Hair, teeth, etc...The cyst is IN your ovary as all cysts are. It could also be a more common Endometrioma, or chocolate cyst. These are blood filled cysts and are VERY common to women with a history of endometriosis. Do you have a history of that? Common Symptoms of endometriosis are heavy, painful periods but increase overy the years to pain with ovulation, intercourse, IBS and/or bowel movements, Urinary pain, etc... No matter what the cyst is if it continues to grow it will need to be removed. This is generally a minor operation called a laperoscopy. They insert a scope through your belly button, another smaller one above your bikini line. You may or may not need the ovary removed but most doctors can remove the cyst without taking the ovary. It might depend on your conception desires, etc... With a complicated cyst ALL of it must be removed or it will return! What you DON'T want is for it to rupture! Your ovary is only 2-3 cm big. A cyst bigger than that is naturally going to hurt!!!! Some doctors say 6 while others say 8 cm's is a problem and needs to be removed. It really makes no differance! If a 4 cm complicated cyst ruptures you WILL feel it and it WILL hurt! The stuff in there can be compaired to super glue and will bind your organs together! I had a 4 cm Endometrioma ruputre that caused my tube to wrap around my lower large intesine and bind my bowel, ovary and uterus together. That hurts too! SO...While I know cancer is a scare!!!!!!! It is also most likely very slim depending on your age! But no matter what this is a problem that you need to take seriuosly!!!!! Don't let your doctor put it off when your CA125 comes back normal! The cyst has to go! Your pain is real and your doctor needs to do something about that! Good Luck to you!