fast growing cyst

I had a normal yearly gyno visit 3 months ago.  For the past few weeks I have been having pressure on my rectum.  This past week-end I started having trouble urinating.  I went to my gyno on Mon., she found a pelvic mass the size of a grapefruit.  I had an ultrasound on Wed.  The findings were that I have a cystic mass measuring 11.1x7.1x10.4 cm with multiple echoes within.It is in the cul-de-sac arising from right to left. It is definately from free fluid.  It is well defined and appears to be a complex cyst.  Help!! I'm scared! I have an appt with an oncologist Mon. morning.  What are the chances this could be malignant?  I just turned 39.  Whatever this is it is fast-growing.

[PFunk]

Do you mean gynecologic oncologist?

[becca-ann]

I had surgery on July 9th.  It turned out to be an endometrioma.  I had never been diagnosed with endometriosis before.  Thank God everything was benign!  I did have a total hysterectomy.