Is Biopsy Required For Adnexal Cysts Classification?

I recently had a pelvic ultrasound with transvaginal imaging. I have a fibroid on the anterior wall and also adnexal cysts. The physician listed his impression as 1. Prominent follicles in both ovaries. 2. Small anterior uterine wall fibroid. I've read that the adnexal cysts can be benign or cancerous. Do I need to get a biopsy to determine this?