Can A Simple Ovarian Cyst Turn Malignant In The Future?

I am a 52 year old woman with a simple ovarian cyst 5cm x 4 cm x 5cm.
Ultrasound and MRI show no signs of malignancy and CA 125 blood tests normal.
I do not produce eggs due to hypopituitarism so cyst cannot be functional
My gynaecologist wants to wait for months and re-scan me but I am worried in case cyst is malignant or turns malignant.
How quickly can a simple benign looking cyst turn malignant, and should I wait as advised?
Thanks