It was a dermoid cyst and was removed by laparotomy (ie the big cut, not keyhole - to protect fetus) when I was 14 weeks pregnant. Let me know if you are facing the same decision (remove it or monitor it for rest of pregnancy after which you must get surgery anyway), and I can expand on this. Basically they didn't know it was benign until after cutting it out. So it was a cancer issue - hideous!