I recently had ovarian dermoid cysts removed, and I recall when meeting the physician they told me that dermoid cysts do have to be removed. Unlike "watery" ovarian cysts (like those you see in poly cystic ovarian syndrome) these dermoid cysts are very different, and are more similar to benign tumours that will keep on growing indefinitely (with dermoid tissue/hair/teeth/etc inside). I found this website by the National Library of Medicine that does a nice job of summarizing ovarian cysts (this might be too basic for your purposes), and it might be useful
NOTICE: The information provided on this site is not a substitute for professional medical advice,
diagnosis, or treatment. Never delay or disregard seeking professional medical advice from your
physician or other qualified health provider because of something you have read on Wellsphere.
If you have a medical emergency, call your doctor or 911 immediately.