Sayang, this is something you really need to discuss with your gynae ASAP, don't worry, but dermoid cyst during pregnancy kena proper medical assessment la, especially at 16 weeks. Your doctor akan tengok if it needs monitoring or any action, tapi dia yang boleh assess your specific situation and baby's safety. I know it's scary lah being first-time mom with this uncertainty, but honestly the best thing is to get proper guidance from your gynae rather than wait. Jangan stress dulu, go book an appointment if you haven't already, and ask them all your questions about baby. Sending you strength!