Post menopausal 47 yr old, large complex cyst: chances??

Hi, I am a post menopausal 47 yr old, healthy but with a history of small, benign ovarian cysts.

I have a rapidly growing, 8 x 5 inch multi-chambered cyst on left ovary.

My CA-125 was 16.
I am in a foreign country and they want to take out the cyst, biopsy it and then do an immediate full hysterectomy if the cyst is malignant or borderlne.

From what I have been reading on the web, I understand that this is normal procedure so I am ok with it....

but my ultrasound showed the cyst to be multi-chambered, which the physician says is not a good sign...and since I am past menopause, I am very worried.

There is no fluid, and the CA test was good....what chances does someone in my situation have of having a benign multi-chambered cyst?

I am nervous as the operation is in 4 days.
Thanks!