20 weeks pregnant with a septated ovarian cyst

I am 20 weeks pregnant and at my most recent ultrasound they found a 10 cm x 8 cm septated cyst on my left ovary.  I understand that ovarian cysts are quite common in pregnant women but what about cysts that are septated?  There is a team of doctors, including an ultrasound specialist from the ovarian cancer department, reviewing my case in a few days.  In the meantime I am quite concerned about the likelihood of this being malignant. What are the chances of this being cancer?  I also understand that the size is quite large, given my pregnancy, at what point do they typically opt to remove a cyst of this size?  Lastly, if they opt to not remove it while I am pregnant, is it possible to biopsy the cyst to rule out malignancy?  Thanks for your opinions, these 5 days of waiting are quite hard on this pregnant lady.